Answers to questions:
The batteries are Discover EVL16A-A batteries. A single string of 8: 390AH @48V nominal. We had one fail last year, showing a significantly raised internal resistance when tested under a load then under charge. There is another one showing signs of weakness, but currently under a 30A draw it is only 0.12V lower than the highest battery in the mix, and 0.05V from the average battery voltage. Readings were: 6.0, 5.88, 6.0, 5.93, 5.92, 5.91, 5.93, 5.94 using a 1500W space heater as a constant load during the test. There are more loads than just networking and security that the client just recently disclosed. Gotta love the added loads to the design. There is a satellite DVR, 2x4 camera webcam systems, cell modem, simplisafe security system, chest freezer, 4 wifi range extenders to serve the less reliable security camera system, and 26W LED dusk-dawn light. I have already talked to them about thinking hard on what items can be removed for the winter at least (DVR is going away, and one of the camera systems too, likely the one requiring the wifi range extenders). All other seasons the system is fine. As for the DC converter(s) we would get a voltage specific converter for any unique voltages, depending on the # of unique items, we would likely abandon that approach if it got to bee too complicated. But thank you to all that provided guidance there. The meanwell units seemed to have the right specs to do the job if we go that route. We would also install them using a LVD of some sort, set somewhere above the standard low voltage cutoff of the rest of the system. We would also only go this route if all AC loads could be removed by doing this, allowing us to remove the 36w idle draw of the Outback. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 Lead Systems Designer for: <http://www.dovetailsolar.com/> www.dovetailsolar.com Ph: 740-274-0139 We’ve completed nearly 400 renewable energy projects! Check out a few in our photo gallery: <http://www.dovetailsolar.com/Our-Work.aspx?path=commercial+-+solar+electric> http://www.dovetailsolar.com/Our-Work.aspx?path=commercial+-+solar+electric This email message and attachments are intended only for the addressee. It may contain information which is legally privileged, confidential and exempt from disclosure. If you are not the intended recipient of this message, you may not disclose, print, copy or disseminate this message and/or the information contained in the message. If you have received this message in error, please reply and notify the sender (only) and delete this message along with any attachments. Unauthorized interception of this email is a violation of criminal laws and laws covering electronic communications privacy matters. From: RE-wrenches [mailto:[email protected]] On Behalf Of Starlight Solar Power Systems Sent: Tuesday, January 16, 2018 11:08 AM To: RE-wrenches <[email protected]> Subject: Re: [RE-wrenches] Off grid DC Loads: DC Converter I too would like to know the make and model of batteries that are loosing capacity. In the past 5 years we have experienced abnormally high failures from 2 brands. Larry On Jan 15, 2018, at 2:00 PM, Jay <[email protected] <mailto:[email protected]> > wrote: Can you tell us: Battery make,model and size? Jay Peltz power. On Jan 15, 2018, at 12:32 PM, Daniel Young < <mailto:[email protected]> [email protected]> wrote: Hello Wrenches, I have a client that is running into an issue with his off grid system. The system is 3yrs old and they are starting to notice their AGM battery bank is loosing capacity, in reality they are noticing the generator is triggering more often. They want to try to lower the frequency of the generator triggering if possible. The system is not occupied during much of the winter (unconditioned, which further hurts the battery bank capacity), but the client has a security system with a cell modem installed and always on. This fortunately allows Optics-RE access, but unfortunately based on the FNDC shunt readings, is pulling a consistent 150w from the battery bank. Currently the network and security equipment is powered from standard wall-warts running on AC. I’d like to help the client extend the time between generator cycles by taking the network loads and powering them directly from the battery bank (the loads are all 12Vdc). Does anyone have any recommendations for a decent quality DC_DC converter that would be applicable? Given inverter losses and the efficiency of the typical wall-wart, I’d expect the running loads to be closer to 80-100w rather than the 150w we see now. The intent is to then take the inverter into search mode, or even switch it off, to remove the tare losses there, and also to take all the wasted power from the standard wall-warts and go to a single, more efficient dc power supply. Any recommendations on a good DC_DC converter are appreciated. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 Dovetail Solar and Wind __________________________ _______________________________________________ List sponsored by Redwood Alliance List Address: <mailto:[email protected]> [email protected] Change listserver email address & settings: <http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: <http://www.mail-archive.com/[email protected]/maillist.html> http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: <http://www.re-wrenches.org/etiquette.htm> www.re-wrenches.org/etiquette.htm Check out or update participant bios: <http://www.members.re-wrenches.org/> www.members.re-wrenches.org
_______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
