Added a winter/cloud cover boost to my solar array

Author	Message
analog8484 Senior Member Joined: 11/11/2021 Location: United States Posts: 222	Posted: 04:08pm 21 Jun 2025         Solar Mike said   So I cobbled together a 24v bank 200AH bank of Lifepo4 cells (8 cells) wired in parallel to the lead carbon setup. As the end point voltages of both batteries are similar, it makes a great combination. The Lifepo4 cells can take 150 or so amps charge with no issues and absorbing any excessive charge from the additional PV. Besides giving some extra capacity, the Lifepo4 bank really does all the heavy lifting, with the lead carbon bank taking over when the Lifepo4 cells start going flat, a high current vacuum relay switches them out of circuit when they get too low. I've wondered how such setup might work.  Assuming you have a BMS on the LFP bank, do you see the lead batteries help with surge power that goes beyond the LFP BMS surge limit? Would you mind sharing the vacuum relay you are using? Thanks