I'm looking to expand my battery bank from 4 to 6 batteries and need help figuring out how to wire them together to achieve a 36V output. Currently, I have 4 batteries set up in parallel, and it's been working great for over a month. However, I'm limited to adding just 2 more batteries along with a new inverter, and I'm struggling to find a clear image or instructions on how to connect everything. Any detailed guidance or visual help would be much appreciated!
3 Answers
When wiring your 12V batteries, connect the positive terminal of the first battery to the negative terminal of the second, and do the same for the second and third. The free terminals on the first (negative) and the third battery (positive) will connect to your busbar, which will be at 36V. Make sure to include disconnects for safety!
Just a quick note: lots of battery manufacturers recommend using a maximum of 4 batteries in parallel regardless of how you set them up. For instance, Weize suggests this for their 12.8V LiFePo4 batteries. You might want to think about this before going ahead.
So, if you're set on 36V, you'll need to wire 3 batteries in series first, connecting them to a busbar. Then, do the same with the other 3 batteries and connect that set to the same busbar. Don't forget to use balancers and fuses on each string to keep everything safe! Just keep in mind that 36V isn't super common, so you might want to consider 24V or 48V instead if that's an option for you.
Just to clarify, when connecting batteries, linking a positive terminal on one battery with a negative on another increases the voltage. But linking batteries of the same polarity keeps the voltage the same but increases capacity. So if you connect two 12V 100Ah batteries, you'd have 12V 200Ah.