I'm gearing up to build my first solar battery generator and I have a couple of questions to make sure I'm on the right track. I plan to use either an 8s2p or an 8s1p configuration with LiFePO4 cells. If I decide to create two separate 8s1p packs and then connect them in parallel, will I need a battery balancer to ensure both packs stay at the same voltage? I've seen some discussions where users with 2-3 24-48V batteries ran into issues where one battery would die while the others remained fully charged.
Another thing on my mind is the bus bars for connecting the cells. I can get some aluminum bars for free, measuring 1/4" thick and 2" wide. Is there a downside to stacking two bars together to make them 1/2" thick instead of buying thicker aluminum? I'm planning to use high amp batteries and run devices like an 1800 watt heat gun that draws 75 amps at 24V.
1 Answer
For your setup, if you're going for 16 cells, I'd suggest going with 48V. It maintains lower current on the DC side which is more efficient and makes wiring easier. If you're connecting multiple battery packs in series, an external balancer is a must to keep everything in sync. Also, when it comes to bus bars, copper is definitely the way to go. Aluminum isn't ideal since it forms an oxide layer quickly, which could cause future issues. Just my two cents!
Thanks for that insight! I considered 48V but wanted to keep it portable with just 8 cells. The case I have can fit 16, and weight isn't too big of a deal for me since I have a truck. I was also looking into the LEV60s batteries, which handle 180A per cell, so I thought 24V could work. Do you think I should reconsider if I can fit the extra cells?