I'm setting up a new battery system in my motorhome. My main house battery (100Ah AGM) is positioned up front, but my inverter charger is at the back, creating a 25ft run with 4AWG cable. I'm planning to add a second battery, which will be located near the inverter and only requires a 3ft run. According to Ohm's Law, it seems like 8AWG cable would suffice to equalize the current, but that feels a bit too thin for comfort. Should I stick with 4AWG for the second battery connection to avoid issues like boiling the closer battery?
1 Answer
Actually, 2AWG is thicker than 4AWG, but it sounds like you’re talking about using 8AWG which might be too thin. To connect your batteries, make sure the positive terminal from one battery connects to the negative of another for parallel wiring. You should also consider having a fuse at each battery's positive terminal for safety. Depending on how old your first battery is, the performance might be affected, and it could be better to use two new batteries if possible.
I misunderstood the gauge chart initially and just corrected my post to mention 8AWG instead.