Re: [EVDL] EVangel-about: San_Antonio-TX Tesla Supercharger site ...(Watt-me-worry)
tps://s3.amazonaws.com/plugshare.production.photos/photos/485546.jpg > >>& the rest are on a back row with the utility power cabinets > >> https://s3.amazonaws.com/plugshare.production.photos/photos/485547.jpg > >>(note: the huge boulders placed in front of the power cabinets. > >> Rocks, boulders, stone work are all valued on this n.west sa > >> side of I-10 Hwy. Stone colors, light tan to reddish brown are > >> worn or used everywhere. Those boulders cost the shopping center > >> the superEVSE is located in, a large chunk of moola. They also > >> protect againt inebriated 4x4 monster ice attacks from hi-speed > >> bashing those cabinets). > >> > >> In the 1st image link, I cane walked over to yak at the (red > >> on the left) Tesla-3 EV driver sitting while charging. He was > >> kind enough to share with me, that he was from San_Diego-CA and > >> was eco-touring, driving to FL using I-8 Hwys. > >> > >> In my trip to relocate to TX, I found parts of I-10 were > >> quite (teeth-chatteringly) rough on the suspension. So, I > >> slowed to 60mph in the right lane (on a Hwy with 70 &80+ mph > >> speed limits). It got better when I got near TX, but you need > >> to bring/have on you proof you are a citizen.us as there is > >> a check-point at El_Paso-TX. > >> > >> The Tesla-3 driver said he was down to 35mi range (and > >> getting concerned) when he pulled in. He said his > >> infotainment screen was showing he was pulling 144kW into his > >> EV pack. Since is SOC was low, he would be drawing near > >> maximum charging current. > >> > >> This tells me this was not your (old-school) 120KW superEVSE, > >> but a newer V2 touting 150kW capability (others please verify, > >> correct): > >> https://www.google.com/search?q=supercharger+v2 > > > >I could be wrong but I don't believe there is any hardware > >difference between 150kw SuperChargers and 120kw. I believe all 120kw > >were software upgraded at the same time to do up to 150kw for certain > >cars under certain conditions. I don't believe that there are any old > >90kw SuperChargers out there; I believe all have been hardware upgraded > >to 120/150kw. > > > >I believe only Model 3s can reach near 150kw, not Ss or Xs. Or maybe > >not all Ss and Xs; I would guess that Raven (new S) will do 150. As > >they age, the upper limit seems to get cut back; my old S (126k miles) > >has done no more than 86kw for over a year. > > > >A few months ago, I was within a few hundred miles of Las Vegas which > >hosts, I think, the only not California 250kw SuperCharger. I was > >sorely tempted to divert just to experience the 250. That is, with my > >newer Model 3. The 3 uses far less charging time than you might expect. > > A lot due to better efficiency than Ss and Xs and some due to faster > >charging batteries. Ss would typically start at about 400 mph (about > >110-115kw) and quickly drop off. 3s go to 500+ mph and do not drop off > >as rapidly. > > > >___ > >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >ARCHIVE: http://www.evdl.org/archive/index.html > >INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > > > >-- next part -- > >An HTML attachment was scrubbed... > >URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/1897dc7d/attachment.html > > > >___ > >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >ARCHIVE: http://www.evdl.org/archive/index.html > >INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > > ___ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/f1a5f0e2/attachment.html> ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] EVangel-about: San_Antonio-TX Tesla Supercharger site ...(Watt-me-worry)
n he pulled in. He said his infotainment screen was showing he was pulling 144kW into his EV pack. Since is SOC was low, he would be drawing near maximum charging current. This tells me this was not your (old-school) 120KW superEVSE, but a newer V2 touting 150kW capability (others please verify, correct): https://www.google.com/search?q=supercharger+v2 I could be wrong but I don't believe there is any hardware difference between 150kw SuperChargers and 120kw. I believe all 120kw were software upgraded at the same time to do up to 150kw for certain cars under certain conditions. I don't believe that there are any old 90kw SuperChargers out there; I believe all have been hardware upgraded to 120/150kw. I believe only Model 3s can reach near 150kw, not Ss or Xs. Or maybe not all Ss and Xs; I would guess that Raven (new S) will do 150. As they age, the upper limit seems to get cut back; my old S (126k miles) has done no more than 86kw for over a year. A few months ago, I was within a few hundred miles of Las Vegas which hosts, I think, the only not California 250kw SuperCharger. I was sorely tempted to divert just to experience the 250. That is, with my newer Model 3. The 3 uses far less charging time than you might expect. A lot due to better efficiency than Ss and Xs and some due to faster charging batteries. Ss would typically start at about 400 mph (about 110-115kw) and quickly drop off. 3s go to 500+ mph and do not drop off as rapidly. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/1897dc7d/attachment.html> ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
Cor van de Water via EV wrote: The leaves do not need to contact each other in any other point than at the battery terminal screw which compresses them into one flat ring. Ah yes; good point. Sometimes they are actually insulated from each other, such as in high current switchmode power supplies. The "skin effect" causes high frequency currents to flow predominantly in the surface of thick conductors. So, they laminate buss bars or use insulated strands of wire to keep the thickness small. I should also mention that it is important that the layers *do* make good contact at the ends. It is all too easy for only the bottom surface of the bottom leaf to make good contact with its terminal. The others have extra "contact" resistance, and so carry proportionately less current. The top leaf carries the least current. You might think the bolt will conduct current up to the top leaf. But the bolt is often steel (or worse, stainless steel), which has very high electrical resistance. Thermal imaging is a quick easy way to evaluate connectors. But for a more accurate indicatin, I prefer to draw a known current, and measure the voltage drop with a multimeter. This can readily show you the resistance of the bolt, current variations between leafs, etc. Lee Hart -- There is a computer disease that anybody who works with computers knows about. It's very serious, and interferes completely with your work. The trouble with computers is that you 'play' with them! (Richard Feynman) -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
Mr. Sharkey said (in part): > Soft aluminum and copper make me queasy when I have to test the > threads. I played it safe and only torqued to 8 ft.lbs. Anyone know > the official torque spec on Thundersky's? No idea on the Thundersky. The large Telecomm batteries we use at work are 110 inch pounds - or about 9 foot pounds. We torque them all correctly. 73 - Jim Walls - K6CCC j...@k6ccc.org ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
>> Glad you found something! Yeah, me too. I went all around the battery and tested torque on the rest of the 74 bolts, and only found a few that needed an extra foot-pound or two. The threads have been coated with anti-seize, so there is good lubrication, but I'm really gun-shy (wrench-shy?) about pulling down too hard and yanking the threads out of the cell posts. Soft aluminum and copper make me queasy when I have to test the threads. I played it safe and only torqued to 8 ft.lbs. Anyone know the official torque spec on Thundersky's? >> The leaves do not need to contact each other... Yes, I did know that, but I had some concern that the ends of the leaves were still a little wrinkly, and might not be flattening enough. Looking at the patterns in the "Bad_Straps.jpg" image, it looks like there was pretty good contact area going on, just not enough pressure. I guess the good news in all this is I only made one run into town and back with loose hardware, and the cell terminal posts looked fine, in spite of the straps getting a little scorched. Thanks everyone for the suggestions. Maybe next I'll launch into a tale about what happens when you short out a pair of series connected Leaf modules by putting the bus bars on wrong (surprising outcome!). ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
Mr. Sharkey said (in part): > Well, it looks like this issue may have been one of my own making. > When I went to remove the cell interconnect strap, both bolts into > the cell terminals were "just snug", not tight. Apparently I got > distracted when completing the BMS card swap, and didn't torque the bolts. That was the important part. The next few paragraphs were not the issue. Just snug was your issue. Glad you found something! Jim Walls ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
The leaves do not need to contact each other in any other point than at the battery terminal screw which compresses them into one flat ring. Sent from Mail for Windows 10 From: Mr. Sharkey via EV Sent: Wednesday, October 2, 2019 4:18 PM To: ev@lists.evdl.org Cc: Mr. Sharkey Subject: Re: [EVDL] LiFePO4 Thermal Imaging Opinions? Well, it looks like this issue may have been one of my own making. When I went to remove the cell interconnect strap, both bolts into the cell terminals were "just snug", not tight. Apparently I got distracted when completing the BMS card swap, and didn't torque the bolts. The straps are made up of four .025" "leaves" of copper stock, with a little hickey bend in the center for mechanical relief between the cells. A sleeve of heat shrink tubing protects the center of the completed strap, and holds it together for assembly on the pack. This was one that I had disassembled to repair, probably because it had been intentionally bent by the previous owner to do something that it wasn't intended to do. When I took it off, it didn't look at all unusual on the top, and the bottom looked fine, it had been in complete contact with the cell terminals by the appearance of the anti-corrosion grease. Inside was a different matter. I cut the heat shrink off and found this: http://www.westlanetv.org/~sharkey/evgfx/Hot_Strap.jpg The four leaves from right-to-left are top-to-bottom, respectively, and the bottom of the photo is the end that was connected to the too-warm cell in the IR photo. I wish I had been able to use some brand name green abrasive pads instead of the dollar-store pretend ones, cleaning the discoloration out of the straps would have been much easier. Afterwards, I hit them with real white Scotchbrite, then gave them a shine with Brasso for good measure. A wash with denatured alcohol, and I put them back on the cells. I'm going to go all over the battery and check all the fasteners for proper torque before putting the cover back on the pack. In the long term, I think I might build a new strap. If this one was so abused that I needed to take it apart to use it again, there may be some issues with the leaves not making as complete of a contact with each other as new, flat straps made from new stock. I don't have any .025 stock, so I use five leaves of .020 copper to build new straps. I hope to have another session with the IR camera next week to see if my efforts to correct this little screw-up have been successful. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/d9339c05/attachment.html> ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] EVangel-about: San_Antonio-TX Tesla Supercharger site ...(Watt-me-worry)
ers please verify, > correct): > https://www.google.com/search?q=supercharger+v2 I could be wrong but I don't believe there is any hardware difference between 150kw SuperChargers and 120kw. I believe all 120kw were software upgraded at the same time to do up to 150kw for certain cars under certain conditions. I don't believe that there are any old 90kw SuperChargers out there; I believe all have been hardware upgraded to 120/150kw. I believe only Model 3s can reach near 150kw, not Ss or Xs. Or maybe not all Ss and Xs; I would guess that Raven (new S) will do 150. As they age, the upper limit seems to get cut back; my old S (126k miles) has done no more than 86kw for over a year. A few months ago, I was within a few hundred miles of Las Vegas which hosts, I think, the only not California 250kw SuperCharger. I was sorely tempted to divert just to experience the 250. That is, with my newer Model 3. The 3 uses far less charging time than you might expect. A lot due to better efficiency than Ss and Xs and some due to faster charging batteries. Ss would typically start at about 400 mph (about 110-115kw) and quickly drop off. 3s go to 500+ mph and do not drop off as rapidly. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/1897dc7d/attachment.html> ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions?
Well, it looks like this issue may have been one of my own making. When I went to remove the cell interconnect strap, both bolts into the cell terminals were "just snug", not tight. Apparently I got distracted when completing the BMS card swap, and didn't torque the bolts. The straps are made up of four .025" "leaves" of copper stock, with a little hickey bend in the center for mechanical relief between the cells. A sleeve of heat shrink tubing protects the center of the completed strap, and holds it together for assembly on the pack. This was one that I had disassembled to repair, probably because it had been intentionally bent by the previous owner to do something that it wasn't intended to do. When I took it off, it didn't look at all unusual on the top, and the bottom looked fine, it had been in complete contact with the cell terminals by the appearance of the anti-corrosion grease. Inside was a different matter. I cut the heat shrink off and found this: http://www.westlanetv.org/~sharkey/evgfx/Hot_Strap.jpg The four leaves from right-to-left are top-to-bottom, respectively, and the bottom of the photo is the end that was connected to the too-warm cell in the IR photo. I wish I had been able to use some brand name green abrasive pads instead of the dollar-store pretend ones, cleaning the discoloration out of the straps would have been much easier. Afterwards, I hit them with real white Scotchbrite, then gave them a shine with Brasso for good measure. A wash with denatured alcohol, and I put them back on the cells. I'm going to go all over the battery and check all the fasteners for proper torque before putting the cover back on the pack. In the long term, I think I might build a new strap. If this one was so abused that I needed to take it apart to use it again, there may be some issues with the leaves not making as complete of a contact with each other as new, flat straps made from new stock. I don't have any .025 stock, so I use five leaves of .020 copper to build new straps. I hope to have another session with the IR camera next week to see if my efforts to correct this little screw-up have been successful. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] EVangel-about: San_Antonio-TX Tesla Supercharger site ... (Watt-me-worry)
... a sa Tesla SuperEVSE site https://www.plugshare.com/location/204964 -- Sent from: http://electric-vehicle-discussion-list.413529.n4.nabble.com/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
[EVDL] EVangel-about: San_Antonio-TX Tesla Supercharger site ... (Watt-me-worry)
Yesterday, I queued to get done lots of chores, as one of my twice weekly outings my VA hospital Dr. (she sez) 'You need to get regular exercise'. The frequency of those outings are to increase as now that September's NDEW EVents are completed, I've re-contacted my realtor to re-hook up with him and get back to my whole reason for moving from Silicon_Valley-CA to become a Texan: to buy a home so-as to live-out my last 10 good-years in (a ~$200k 3+bed,2bath home here, would be ~2+M back there). After I completed my tasks and before I headed back to my rented room (I was feeling the exercise burn and old-man arthritic pain only sleep would reduce), I swung by San Antonio's (sa) newest public EVSE addition: a new Tesla SuperEVSE site https://www.plugshare.com/location/204964https://www.plugshare.com/location/204964 This puts sa on the superEVSE map as an in-route charging destination, which also means we will see a whole lot more Tesla EVs in this area :-) The plugshare listing touts 10 stations, but 2 stations are still wrapped in plastic, thus are not available/not- powered on (perhaps this is for future growth?). I found it interesting that it is located within a couple blocks of my realtor's office. Some Tesla forum posts questioned Tesla's site location choice. But, I feel it is a worthy selection. There is ample food (restaurants), drink (starbucks), shopping (plenty to do while the EV is super-soaking-up high powered L3 juice). The site is just off the I-10 Hwy & the neighborhood is upscale (affluent, yuppie). So, I would feel safe anytime during its 24hr access (though streets tend to roll-up their sidewalks after hours in TX). Unlike the Walmart e.america site I posted about http://electric-vehicle-discussion-list.413529.n4.nabble.com/NDEW-updates-9-14-Austin-9-21-San-Antonio-vw-s-E-America-L3-EVSE-Walmart-tp4695078.html which is Not as easily found just off I-35 Hwy, where you have to zig (counting the drinking/sleeping homeless along side) the rough roads/streets. It too also has 24hr access, but that area is definitely not a safe location after hours. This Tesla superEVSE is easy to spot as most of the stations are in line with the street, see https://s3.amazonaws.com/plugshare.production.photos/photos/485546.jpg & the rest are on a back row with the utility power cabinets https://s3.amazonaws.com/plugshare.production.photos/photos/485547.jpg (note: the huge boulders placed in front of the power cabinets. Rocks, boulders, stone work are all valued on this n.west sa side of I-10 Hwy. Stone colors, light tan to reddish brown are worn or used everywhere. Those boulders cost the shopping center the superEVSE is located in, a large chunk of moola. They also protect againt inebriated 4x4 monster ice attacks from hi-speed bashing those cabinets). In the 1st image link, I cane walked over to yak at the (red on the left) Tesla-3 EV driver sitting while charging. He was kind enough to share with me, that he was from San_Diego-CA and was eco-touring, driving to FL using I-8 Hwys. In my trip to relocate to TX, I found parts of I-10 were quite (teeth-chatteringly) rough on the suspension. So, I slowed to 60mph in the right lane (on a Hwy with 70 &80+ mph speed limits). It got better when I got near TX, but you need to bring/have on you proof you are a citizen.us as there is a check-point at El_Paso-TX. The Tesla-3 driver said he was down to 35mi range (and getting concerned) when he pulled in. He said his infotainment screen was showing he was pulling 144kW into his EV pack. Since is SOC was low, he would be drawing near maximum charging current. This tells me this was not your (old-school) 120KW superEVSE, but a newer V2 touting 150kW capability (others please verify, correct): https://www.google.com/search?q=supercharger+v2 This isn't Tesla's latest. 250kW V3 is supposed to be coming: https://www.google.com/search?q=supercharger+v3+250 ?Is 250kW supercharging for the coming Tesla EVs with huge kWh packs? Or, is this a keep up with the Jones' competition of e.america's 350kW ccs ports at Walmarts? (Am I the only one that thinks 350kW ccs ports is an overkill-waste when no EV.us can use all 350kW? By that time, another Tesla-3 driver came sauntering over to also yak with us. He was a sa local so, he did't need a charge (his EV was parked in a side ice-spot). He wanted know if having access to the superEVSE was worth the effort The S.Deigo driver expressed, for him (a road warrior) it was great. I interjected with a question to know their EV experience level. Neither knew of nor had used plugsahre.com . After explaining it was much more up-to-date thus valuable than chargpoint's wannbe site, plugshare and its apps, were a valuable free tool for EV drivers to get the information they need for long trips, etc. I shared (IMO), knowing what his superEVSE options were would be valuable to his future needs. That although charging at home or rarely at
Re: [EVDL] LiFePO4 Thermal Imaging Opinions? (common mistake)
_ > >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >ARCHIVE: http://www.evdl.org/archive/index.html > >INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >Please discuss EV drag racing at NEDRA > >(http://groups.yahoo.com/group/NEDRA) > > > > ___ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA > (http://groups.yahoo.com/group/NEDRA) > > > > ___ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA > (http://groups.yahoo.com/group/NEDRA) > ___ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20191002/0c524ba0/attachment.html> ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] LiFePO4 Thermal Imaging Opinions? (common mistake)
> ...a couple years ago I used a thermal imaging camera to demonstrate > how hot a lighting controller board got under heavy load. > http://forums.lightorama.com/topic/45960-how-warm-does-a-sandevices-e682-g et/ Warning! A common mistake. The "heat" visible on the eithernet connector has nothing to do with that connector. That is nothing but a reflection of something hot (maybe the person taking he picture). Notice how in every view, there is variation in the "heat" image of that shiny connector. This is because SHINY METAL does not radiate heat very much but it does provide excellent specular reflection. So all you ever see of a shiny metallic component is what it is reflecting, nothing at all about its own temp. A very common mistake. The Thermal emissivity of everything in view is *assumed* to be about 0.9. The operator has to know enough to discount any reading of any material this is not 0.9 ish. True, most things are, but definitely NOT shiny metal! Aluminum is 0.03 or 30 times less emissivity. (that is why we wrap it around a baked potato!). Hold up a baking tin, it acts like a thermal mirror to everything in the room. You are seeing nothing about its own temperature. Bob, WB4AAPR -Original Message- From: EV On Behalf Of jim--- via EV Sent: Tuesday, October 1, 2019 2:21 PM To: Electric Vehicle Discussion List Cc: j...@k6ccc.org Subject: Re: [EVDL] LiFePO4 Thermal Imaging Opinions? Yes. Heat is going to conduct better through the metal plates of the batter vs the electrolite. Therefore, the heat if generated at the connector is going to conduct along the metal plates. Assuming that the plates in that battery are vertical, I would expect something similar to what is being seen. Also note that the strap is FAR hotter than the portion of the strap visible at the left edge of the IR image, and that the right end of the strap and the top of the cell on the right that is connected to that strap is also warm. There is a lot of heat being generated in the strap or more likely the connection between the left end of the strap and the top of the battery. We use IR images using similar equipment here at work for checking electrical connections quite regularly. For a little entertainment, a couple years ago I used a thermal imaging camera to demonstrate how hot a lighting controller board got under heavy load. I posted the results on a Christmas Lighting forum. You should be able to read it - although you can't post a reply unless you are a member of that forum. http://forums.lightorama.com/topic/45960-how-warm-does-a-sandevices-e682-g et/ Jim -Original Message- From: "Peri Hartman via EV" Sent: Tuesday, October 1, 2019 10:53 To: "Electric Vehicle Discussion List" Cc: "Peri Hartman" Subject: Re: [EVDL] LiFePO4 Thermal Imaging Opinions? Wow, hat's a great observation. Question: is it significant that the IR image also shows heat emanating vertically, appearing to be relatively uniform ? Peri -- Original Message -- From: "jim--- via EV" To: "Electric Vehicle Discussion List" Cc: "j...@k6ccc.org" Sent: 01-Oct-19 10:36:24 AM Subject: Re: [EVDL] LiFePO4 Thermal Imaging Opinions? >> A close-up of the cell, looking from the front of the pack. It's been photoshopped to blend the IR image with the visible image to provide some perspective of the actual appearance: >> >> http://www.westlanetv.org/~sharkey/evgfx/Hot_Cell_2.jpg > >Carefully check the connection on that cell that is closest to the camera. Note that only the one end of the cell is warmer - not both ends. I would suspect that the connection is marginal and causing the heat. The heat has conducted into that end of the cell. > >73 >- >Jim Walls - K6CCC >j...@k6ccc.org > > >___ >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >ARCHIVE: http://www.evdl.org/archive/index.html >INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org >Please discuss EV drag racing at NEDRA >(http://groups.yahoo.com/group/NEDRA) > ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
