I’ve done this many times I use an Iota or power max charger to run the DC.
Jay > On Apr 23, 2024, at 2:42 PM, Jason Szumlanski via RE-wrenches > <re-wrenches@lists.re-wrenches.org> wrote: > > > I have an off-grid client who is working on replacing old equipment at a > cabin. He has a lot of 12 volt distribution in the house for lighting, fans, > and a 12 volt refrigerator. He also has 120 volt AC loads that run through a > separate distribution panel where the only source is a 2000 Watt Honda > generator. There is no inverter present. The batteries are charged through a > Trace C40. > > He currently has a few ancient solar panels and a struggling Bank of AGM > batteries. It's time for an upgrade. I can easily supply enough PV power for > what he needs. He currently has a 9 kilowatt hour battery capacity that he > was happy with when the batteries operated optimally. Nonetheless, I would > probably future-proof him with a 10 to 15 kilowatt hour LiPo to double or > triple his usable capacity. > > For convenience, obviously it would be nice to have an inverter to eliminate > or reduce the generator requirement. But he seems committed to keeping his 12 > volt distribution because it would be costly to replace fixtures. I think he > would consider replacing the 12 volt refrigerator if he has an inverter. > > He definitely wants LiPo batteries. > > I don't like the idea of 12 volt direct from a battery plus connecting an > inverter to that same battery. It is going to be hard to measure and monitor > things. > > I am thinking about using a 48 volt battery with a single phase 120 volt > inverter, getting him to change to a 120 volt refrigerator, and using a DC > converter to give him somewhere in the range of 100 amps at 12 volts for his > existing DC lighting and fan loads. Is this a bad idea? Should I stick with a > 12 volt battery system? He does have a tiny 12 volt pressure pump which might > be an issue for the converter. I'm not sure. I am a bit worried about the > efficiency loss and capacity of DC converters and not sure how to size it. > > Jason Szumlanski > Florida Solar Design Group > > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
