Hey everyone! I'm in the middle of upgrading my solar power system and I'm planning to switch from a budget-friendly 12V 100Ah lithium battery to a more powerful 12V 150Ah lithium battery, which has its own Battery Management System (BMS). I was considering hooking these batteries up in parallel since they both are lithium and share the same voltage. However, I've heard that I need to use fuses to prevent any issues. I'm not sure about the maximum current draw for these batteries, but I know the new one is rated for a max draw of 150A. Should I get a fuse that matches this rating or maybe something else?
2 Answers
You can definitely connect those two batteries in parallel since they have the same voltage. Just make sure to get fuses that are rated slightly higher than what each BMS can handle. It’s super important not to skimp on fuses! I suggest looking at products from Blue Sea Systems—they have good terminal blocks and fuses. Also, consider putting in isolation switches for each battery; this way, you can easily manage them when needed without trouble!
Fuses are more about protecting your wiring than the batteries themselves. Make sure you find out how much current your wiring can handle and choose fuses accordingly. The biggest risk is if someone messes with the wiring and accidentally shorts things out, so pick a fuse that’s rated a bit above the main wiring fuse for safety.
Just a heads-up: while you can wire different Ah batteries together temporarily, it might shorten the lifespan of the lower-rated battery. Just keep that in mind!