Re: [WISPA] Remote Powered Access Pont
One source: http://tnrbatteries.com/genesis.html - Original Message - From: Chuck McCown - 3 [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:12 PM Subject: Re: [WISPA] Remote Powered Access Pont http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf Genesis pure lead EP or XE version will work down to -40. They are rated for 100% depth of discharge. Repeatedly. 400 times. And can come back from 100% discharge at -40 to be fully charged. They are good for 2 years sitting on the shelf totally unused. I don't know of any other battery that can do that. They also have most of their energy available at super cold temperatures, where flooded cells lose most of their energy when cold. But you will pay 2 to 3 times more than for a Trojan. I figure everything by watt hour first. So you need 5 watts * 24 hours * 30 days = 3600 watt hours. At 30 cents per watt hour, you will end up paying more than $1000 for that battery. Hopefully you can shop around and find them for less. I used to pay 20 cents. I don't know why they went up so much. Watt hours / system voltage = amp hours 3600/12=300 amp hours. One of our supervisors recently found a good price (if you can call it good) for the gates/hawker/enersys batteries. If I can find the source I will post it. - Original Message - From: rabbtux rabbtux [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 8:27 PM Subject: Re: [WISPA] Remote Powered Access Pont Thanks for the great info Chuck! Almost made the trojan battery mistake. what exactly is the battery technology and brand you suggest? if I have a 5 watt system you suggest a 120W solar panel. Also 30 days or 360AH of usable capacity at 12V? Thanks for the clarification, and the pics that make your experience clear! On Wed, Nov 19, 2008 at 7:38 PM, Chuck McCown - 3 [EMAIL PROTECTED] wrote: At 60% depth of discharge they freeze at 0F. Once frozen they are dead. Liquid electrolyte batteries need to be liquid to work. Not to mention the risk of a broken case. (You most likely mean you try to avoid taking them below 40% DOD, but 60% has a nice freezing point to exploit for purposes of rhetoric). Trojans were designed for the cabin with the fireplace and the intermittent use of the residential solar application.(Really, they were designed for golf carts). Constant load, constant nightly cycling, periods of no charging and deep discharge during the coldest days of the year is a different application and takes a different battery technology. Here is a good VLRA white paper on the temperature issue: http://www.cdtechno.com/custserv/pdf/7953.pdf We use VLRAs inside central offices where there is HVAC. Not in the field. And they are much better than flooded cells like the T-105 AGMs go in the field. And for solar only a few types of AGMs can be trusted. This app note is full of lots of good info. It is on the batts we use that will still deliver 40% of their power at -40 degrees. http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf But the only really important point is that in a solar situation, where you have weather and you have low temps, very few batteries will totally recover from an extreme deep discharge. And that happens all the time when people scrimp on their battery capacity and solar panel capacity. 20X watts 30 days autonomy = you will sleep all winter long. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:56 PM Subject: Re: [WISPA] Remote Powered Access Pont Ok. our answer to that problem has always been to double up on our total battery size so we never discharge them below 60% Sounds like you are in a much more inaccessible environment than we are! And in that kind of location, I'd likely be looking for the same thing. But, for us, inaccessibility won't last more than a week or so... Chuck McCown - 3 wrote: We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming
Re: [WISPA] Remote Powered Access Pont
Depending on where this is, you may be able to mount a small wind generator. http://www.solardyne.com/air403wingen.html John Chuck McCown - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
They must not be subject to ice storms. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:22 AM Subject: Re: [WISPA] Remote Powered Access Pont We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Good point :) It's not too severe down here in So Utah. Randy Chuck McCown wrote: They must not be subject to ice storms. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:22 AM Subject: Re: [WISPA] Remote Powered Access Pont We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org
Re: [WISPA] Remote Powered Access Pont
Wind generators are good if you have plenty of wind and no ice. Our problem has been that we need their power during the worst weather. And that is when they fail. They wear out or get loaded with ice and tear apart. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 11:04 AM Subject: Re: [WISPA] Remote Powered Access Pont Good point :) It's not too severe down here in So Utah. Randy Chuck McCown wrote: They must not be subject to ice storms. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:22 AM Subject: Re: [WISPA] Remote Powered Access Pont We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org
Re: [WISPA] Remote Powered Access Pont
Your panel sizing is right on, but you don't need that much battery cost. Golf Cart batteries, which are near 200 each, are more than enough for a 12 volt system. insert witty tagline here - Original Message - From: Chuck McCown - 3 [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Wednesday, November 19, 2008 4:47 PM Subject: Re: [WISPA] Remote Powered Access Pont I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Lead acid batteries won't freeze unless discharged more than 50%. for winter, just insulate them well to shield them from severe temperature spikes and make sure you have more charging power than you need, and you're good to go. insert witty tagline here - Original Message - From: Chuck McCown - 3 [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Wednesday, November 19, 2008 6:48 PM Subject: Re: [WISPA] Remote Powered Access Pont We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:25 PM Subject: Re: [WISPA] Remote Powered Access Pont What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless
Re: [WISPA] Remote Powered Access Pont
I have used a AIR-X for 4 years now. The blades are a composite plastic and the ice WILL NOT stick to them. I've been there when the pole supporting the generator had nearly an inch of ice on it and the antennas were all coated too thick to break off, and the genset blades were ice free. Mark insert witty tagline here - Original Message - From: Chuck McCown [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:13 AM Subject: Re: [WISPA] Remote Powered Access Pont Wind generators are good if you have plenty of wind and no ice. Our problem has been that we need their power during the worst weather. And that is when they fail. They wear out or get loaded with ice and tear apart. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 11:04 AM Subject: Re: [WISPA] Remote Powered Access Pont Good point :) It's not too severe down here in So Utah. Randy Chuck McCown wrote: They must not be subject to ice storms. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:22 AM Subject: Re: [WISPA] Remote Powered Access Pont We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071
Re: [WISPA] Remote Powered Access Pont
You're special, Chuck. :-p - Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: Chuck McCown [EMAIL PROTECTED] Sent: Thursday, November 20, 2008 2:07 PM To: WISPA General List wireless@wispa.org Subject: Re: [WISPA] Remote Powered Access Pont Oh, ice will indeed stick to an air-x. Can you spot it in these photos... I have been doing wind and solar for 30 years. There are those with frozen batts... And then there is me. - Original Message - From: [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 1:01 PM Subject: Re: [WISPA] Remote Powered Access Pont I have used a AIR-X for 4 years now. The blades are a composite plastic and the ice WILL NOT stick to them. I've been there when the pole supporting the generator had nearly an inch of ice on it and the antennas were all coated too thick to break off, and the genset blades were ice free. Mark insert witty tagline here - Original Message - From: Chuck McCown [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:13 AM Subject: Re: [WISPA] Remote Powered Access Pont Wind generators are good if you have plenty of wind and no ice. Our problem has been that we need their power during the worst weather. And that is when they fail. They wear out or get loaded with ice and tear apart. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 11:04 AM Subject: Re: [WISPA] Remote Powered Access Pont Good point :) It's not too severe down here in So Utah. Randy Chuck McCown wrote: They must not be subject to ice storms. - Original Message - From: Randy Cosby [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 10:22 AM Subject: Re: [WISPA] Remote Powered Access Pont We recently visited a solar-powered site that had a supplementary wind-generation system. Seemed to work well for them to have wind power when the weather is bad, solar when it is good. Pretty windy place as well. Chuck McCown - 3 wrote: Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours
Re: [WISPA] Remote Powered Access Pont
feelin' da luv today (As some might suspect, I do have a passion for mountain-top solar and wind power, having had to risk human life on more than one occasion to keep things alive or restore service. $2000 helicopter rides after the storm blows through is also a good reason to get it right. I have quite a few sites and I think I have made every possible mistake you can make. Just one helicopter ride more than pays for the batts that will not freeze.) You're special, Chuck. :-p - Mike Hammett WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Thanks so much for the insight and great information. You just saved me having to make all those mistakes all over again. I was definitely undersizing the system and I'd bet most folks would tend to do that, trying to save costs. One more question: I read that solar panels will still output on cloudy days, maybe 75% of sunny day capacity. Have you any experience with this? Regards, Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck McCown Sent: Thursday, November 20, 2008 1:42 PM To: WISPA General List Subject: Re: [WISPA] Remote Powered Access Pont feelin' da luv today (As some might suspect, I do have a passion for mountain-top solar and wind power, having had to risk human life on more than one occasion to keep things alive or restore service. $2000 helicopter rides after the storm blows through is also a good reason to get it right. I have quite a few sites and I think I have made every possible mistake you can make. Just one helicopter ride more than pays for the batts that will not freeze.) You're special, Chuck. :-p - Mike Hammett WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
We can even detect a little charge due to moonlight. Clouds are such variable density it is hard to give a meaningful answer. Plus there are days that are scattered, broken and overcast cloud conditions. We typically see a 50% reduction of current when clouds pass over on the telemetry. If you are trying to scrape together a system and feel you are falling short, cheap insurance is a small generator (assuming you can access the site). Don't neglect the telemetry. The RMS - BND system is ideal. Packetflux just came out with a new system too. With telemetry at least you can watch it die and not be surprised. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Thursday, November 20, 2008 2:15 PM Subject: Re: [WISPA] Remote Powered Access Pont Thanks so much for the insight and great information. You just saved me having to make all those mistakes all over again. I was definitely undersizing the system and I'd bet most folks would tend to do that, trying to save costs. One more question: I read that solar panels will still output on cloudy days, maybe 75% of sunny day capacity. Have you any experience with this? Regards, Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck McCown Sent: Thursday, November 20, 2008 1:42 PM To: WISPA General List Subject: Re: [WISPA] Remote Powered Access Pont feelin' da luv today (As some might suspect, I do have a passion for mountain-top solar and wind power, having had to risk human life on more than one occasion to keep things alive or restore service. $2000 helicopter rides after the storm blows through is also a good reason to get it right. I have quite a few sites and I think I have made every possible mistake you can make. Just one helicopter ride more than pays for the batts that will not freeze.) You're special, Chuck. :-p - Mike Hammett WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
I appreciate the fact that you not only have made the mistakes for us, but that you are willing to share the experiences instead of sitting back an snickering. Randy Chuck McCown wrote: feelin' da luv today (As some might suspect, I do have a passion for mountain-top solar and wind power, having had to risk human life on more than one occasion to keep things alive or restore service. $2000 helicopter rides after the storm blows through is also a good reason to get it right. I have quite a few sites and I think I have made every possible mistake you can make. Just one helicopter ride more than pays for the batts that will not freeze.) You're special, Chuck. :-p - Mike Hammett WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Randy Cosby Vice President InfoWest, Inc office: 435-773-6071 WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Thanks for the great info Chuck! Almost made the trojan battery mistake. what exactly is the battery technology and brand you suggest? if I have a 5 watt system you suggest a 120W solar panel. Also 30 days or 360AH of usable capacity at 12V? Thanks for the clarification, and the pics that make your experience clear! On Wed, Nov 19, 2008 at 7:38 PM, Chuck McCown - 3 [EMAIL PROTECTED] wrote: At 60% depth of discharge they freeze at 0F. Once frozen they are dead. Liquid electrolyte batteries need to be liquid to work. Not to mention the risk of a broken case. (You most likely mean you try to avoid taking them below 40% DOD, but 60% has a nice freezing point to exploit for purposes of rhetoric). Trojans were designed for the cabin with the fireplace and the intermittent use of the residential solar application.(Really, they were designed for golf carts). Constant load, constant nightly cycling, periods of no charging and deep discharge during the coldest days of the year is a different application and takes a different battery technology. Here is a good VLRA white paper on the temperature issue: http://www.cdtechno.com/custserv/pdf/7953.pdf We use VLRAs inside central offices where there is HVAC. Not in the field. And they are much better than flooded cells like the T-105 AGMs go in the field. And for solar only a few types of AGMs can be trusted. This app note is full of lots of good info. It is on the batts we use that will still deliver 40% of their power at -40 degrees. http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf But the only really important point is that in a solar situation, where you have weather and you have low temps, very few batteries will totally recover from an extreme deep discharge. And that happens all the time when people scrimp on their battery capacity and solar panel capacity. 20X watts 30 days autonomy = you will sleep all winter long. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:56 PM Subject: Re: [WISPA] Remote Powered Access Pont Ok. our answer to that problem has always been to double up on our total battery size so we never discharge them below 60% Sounds like you are in a much more inaccessible environment than we are! And in that kind of location, I'd likely be looking for the same thing. But, for us, inaccessibility won't last more than a week or so... Chuck McCown - 3 wrote: We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:25 PM Subject: Re: [WISPA] Remote Powered Access Pont What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels
Re: [WISPA] Remote Powered Access Pont
http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf Genesis pure lead EP or XE version will work down to -40. They are rated for 100% depth of discharge. Repeatedly. 400 times. And can come back from 100% discharge at -40 to be fully charged. They are good for 2 years sitting on the shelf totally unused. I don't know of any other battery that can do that. They also have most of their energy available at super cold temperatures, where flooded cells lose most of their energy when cold. But you will pay 2 to 3 times more than for a Trojan. I figure everything by watt hour first. So you need 5 watts * 24 hours * 30 days = 3600 watt hours. At 30 cents per watt hour, you will end up paying more than $1000 for that battery. Hopefully you can shop around and find them for less. I used to pay 20 cents. I don't know why they went up so much. Watt hours / system voltage = amp hours 3600/12=300 amp hours. One of our supervisors recently found a good price (if you can call it good) for the gates/hawker/enersys batteries. If I can find the source I will post it. - Original Message - From: rabbtux rabbtux [EMAIL PROTECTED] To: WISPA General List wireless@wispa.org Sent: Thursday, November 20, 2008 8:27 PM Subject: Re: [WISPA] Remote Powered Access Pont Thanks for the great info Chuck! Almost made the trojan battery mistake. what exactly is the battery technology and brand you suggest? if I have a 5 watt system you suggest a 120W solar panel. Also 30 days or 360AH of usable capacity at 12V? Thanks for the clarification, and the pics that make your experience clear! On Wed, Nov 19, 2008 at 7:38 PM, Chuck McCown - 3 [EMAIL PROTECTED] wrote: At 60% depth of discharge they freeze at 0F. Once frozen they are dead. Liquid electrolyte batteries need to be liquid to work. Not to mention the risk of a broken case. (You most likely mean you try to avoid taking them below 40% DOD, but 60% has a nice freezing point to exploit for purposes of rhetoric). Trojans were designed for the cabin with the fireplace and the intermittent use of the residential solar application.(Really, they were designed for golf carts). Constant load, constant nightly cycling, periods of no charging and deep discharge during the coldest days of the year is a different application and takes a different battery technology. Here is a good VLRA white paper on the temperature issue: http://www.cdtechno.com/custserv/pdf/7953.pdf We use VLRAs inside central offices where there is HVAC. Not in the field. And they are much better than flooded cells like the T-105 AGMs go in the field. And for solar only a few types of AGMs can be trusted. This app note is full of lots of good info. It is on the batts we use that will still deliver 40% of their power at -40 degrees. http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf But the only really important point is that in a solar situation, where you have weather and you have low temps, very few batteries will totally recover from an extreme deep discharge. And that happens all the time when people scrimp on their battery capacity and solar panel capacity. 20X watts 30 days autonomy = you will sleep all winter long. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:56 PM Subject: Re: [WISPA] Remote Powered Access Pont Ok. our answer to that problem has always been to double up on our total battery size so we never discharge them below 60% Sounds like you are in a much more inaccessible environment than we are! And in that kind of location, I'd likely be looking for the same thing. But, for us, inaccessibility won't last more than a week or so... Chuck McCown - 3 wrote: We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General
[WISPA] Remote Powered Access Pont
I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Here is a note I posted several days ago on the Motorola list about solar powering. From: Chuck McCown [mailto:[EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:17 AM To: Dave Crim Subject: Re: solar Continuing on a bit, lets say you have 5 lousy days and one good sunny day followed by 5 more lousy days. That one sunny day needs to store enough to charge the batts totally. 75 watts * 5 days * 24hours * 1.25 (batter efficiency loss) + (75watts * 24 hours) current day = 13050 watt hours. To make 13050 watt hours in one 10 hour day you go: 13050/.707*10=1845 watts. You need 1845 watts of panel to do this. That is 24 times the load. So, my rule of thumb of 20 times the load is still a little shy of being conservative. The thing that saves you in a situation like this is a massive battery. A one month battery with 20 X panels will never fail due to a lack of sun energy. A 2 week battery and 10X panels will fail now and then every single winter. Sometimes for several days at a time. - Original Message - From: Chuck McCown To: [EMAIL PROTECTED] Sent: Friday, November 14, 2008 9:09 AM Subject: solar Several thing you may not be including. Assuming this panel is somewhere in this neck of the woods, December 21 has 10 hours of time between runrise and sunset. But if you don't have tracking mounts (most don't) the amount of energy you get out of a panel follows the first half of a sine wave. To estimate that energy, you integrate the area under the curve. That will equal .707 of what you thought you were going to get. So, let's say you put up a 500 watt panel, your daily sunny output will be an average of 353 watts. The sun shines for 10 hours solid and you store 3530 watt hours in your battery. Now your load is on during the daytime, so if you have a 75 watt load, you are now able to make 278 watts. You are down to 2780 watt hours. You put in 2780 watt hours into a battery and you get maybe 80% back out. So you have 2224 watt hour available (if you drain the batts which is not good for them). You have 14 hours of darkness and actually more like 16 hours before the panel starts making any useful amount of energy. 16*75=1200 watt hours. But that next day is not sunny, there is frost and a light coating of snow. The whole works dies 16 hours later. About 9 pm. One other note, you only want to draw your batteries down no more than 10% each night or they won't last long. That means a minimum of 12000 watt hours. If that is a 12 volt system, 1000 amp hours. If it is a 24 volt system, 500 amp hours. And that is a minimum because here we get a week with snow and ice and no sun easy, sometimes two weeks. You really need a generator, less load, or a whole bunch more batts and panels. WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: "Scott Parsons" [EMAIL PROTECTED] To: "'WISPA General List'" wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:25 PM Subject: Re: [WISPA] Remote Powered Access Pont What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Remote Powered Access Pont
Ok. our answer to that problem has always been to double up on our total battery size so we never discharge them below 60% Sounds like you are in a much more inaccessible environment than we are! And in that kind of location, I'd likely be looking for the same thing. But, for us, inaccessibility won't last more than a week or so... Chuck McCown - 3 wrote: We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says "avoid locations where freezing temperatures are expected". It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:25 PM Subject: Re: [WISPA] Remote Powered Access Pont What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: "Scott Parsons" [EMAIL PROTECTED] To: "'WISPA General List'" wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access to grid power. I was curious what you guys use for this type of thing? I figure I need a 30W solar panel, controller, battery and enclosure. How much should I expect to pay for a setup? Is there anything available off the shelf? Thanks for your help. Scott WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ WISPA Wants You! Join
Re: [WISPA] Remote Powered Access Pont
At 60% depth of discharge they freeze at 0F. Once frozen they are dead. Liquid electrolyte batteries need to be liquid to work. Not to mention the risk of a broken case. (You most likely mean you try to avoid taking them below 40% DOD, but 60% has a nice freezing point to exploit for purposes of rhetoric). Trojans were designed for the cabin with the fireplace and the intermittent use of the residential solar application.(Really, they were designed for golf carts). Constant load, constant nightly cycling, periods of no charging and deep discharge during the coldest days of the year is a different application and takes a different battery technology. Here is a good VLRA white paper on the temperature issue: http://www.cdtechno.com/custserv/pdf/7953.pdf We use VLRAs inside central offices where there is HVAC. Not in the field. And they are much better than flooded cells like the T-105 AGMs go in the field. And for solar only a few types of AGMs can be trusted. This app note is full of lots of good info. It is on the batts we use that will still deliver 40% of their power at -40 degrees. http://www.enersysreservepower.com/documents/US-GPL-AM-003_0906.pdf But the only really important point is that in a solar situation, where you have weather and you have low temps, very few batteries will totally recover from an extreme deep discharge. And that happens all the time when people scrimp on their battery capacity and solar panel capacity. 20X watts 30 days autonomy = you will sleep all winter long. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:56 PM Subject: Re: [WISPA] Remote Powered Access Pont Ok. our answer to that problem has always been to double up on our total battery size so we never discharge them below 60% Sounds like you are in a much more inaccessible environment than we are! And in that kind of location, I'd likely be looking for the same thing. But, for us, inaccessibility won't last more than a week or so... Chuck McCown - 3 wrote: We buy batts that are rated to give you the energy down to -20F. Survive being at-20F while discharged to a stone cold state. And recover when the next available bit of sunlight hits the panel (perhaps days later). And last 2000 cycles. For that you pay 30 cents per watt hour. And can sleep at night. (we used to get these for 20 cents, I don't know why they are so much more now) I just found a website selling a T-105 for $160\each 6 volts, 225 aH That comes to 11.8 cents per watt hour. The Trojan website says avoid locations where freezing temperatures are expected. It also says the must be kept fully charged when freezing. Hard to do with solar on a mountain top. http://www.trojan-battery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf So, if you have a nice warm place to keep the trojans then they are a very good value. (assuming they are in an air conditioned place in the summer too, else they won't last too many summers) But most solar powered sites don't have a heater to keep them from freezing and splitting. - Original Message - From: Blair Davis To: WISPA General List Sent: Wednesday, November 19, 2008 7:25 PM Subject: Re: [WISPA] Remote Powered Access Pont What type of battery's are you using? That price sounds very high. 4x T-105 will provide 225Ah at 24V for a cost of about $500 Chuck McCoy's - 3 wrote: I would use a 100 watt panel minimum. And a one month battery. 5watts * 24hours * 30 days = 3600 watt hour battery If you are running a 24 volt system then you need 3600/24=150 aH battery. If you are running a 12 volt system, you need a 300 aH battery. You will pay about 30 cents per watt hour for a battery. So $1080 for the battery. You will pay about $5/watt for the panel, so $500 for the panel. Charge controllers are about $100 or less. If you build it this way it will always work. You can put in half the battery for half the price. But then you have only two weeks of insurance against bad weather. Never ever go below 10X the load for the panel, that will just barely cut it in the sunniest of climates. Even then you will probably have to put in a back up generator and you will be cycling the crap out of your batts causing them to only last a couple of years. If you want 99.999% reliability you have to use a panel 24X the size of the load (unless you have a tracking mount, then you can reduce that). I try to always use 20X panels and no less than a 2 week battery. But even then, a week or two of snow on the panels and gray skies every day can cause an outage. - Original Message - From: Scott Parsons [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Wednesday, November 19, 2008 5:33 PM Subject: [WISPA] Remote Powered Access Pont I'm looking into setting up a remote access point/repeater. Power requirements are 5W. No access
