Hey everyone! I'm looking for help with my RV battery setup. I have two isolated 12V battery banks: one primary bank made of three 200Ah Renogy batteries, and a secondary 600Ah battery that I recently bought. I want to connect them using a heavy-duty selector switch that allows me to choose between these two banks. The problem is, most selectors have a 'both' option, which isn't something I want because my secondary battery is strictly a backup with its own inverter. Does anyone have suggestions for a switch that meets these needs?
3 Answers
What you're searching for is a transfer switch—it’s like switching from shore power to battery power. Just make sure that your backup battery's inverter is wired correctly; you likely won't be able to use it with the transfer switch unless it's set up right.
Sounds like the right move! The other user mentioned I might be overthinking this—tying the new battery into my current setup should work fine despite the age differences.
The reason you likely can't combine those batteries is because they have different ages and possibly different charge states. New batteries might try to help out the older ones, which could end up damaging them. I think balancing issues are indeed a big factor—harder to charge old and new together just because they won't work in sync very well. So you're right to keep them separate!
That makes sense! Would adding older cells affect how much capacity the new battery can charge to?
You nailed it! Newer batteries are likely to try and help the older ones, but that could drain them faster. Better off keeping them isolated!
Check out the Blue Sea Systems 6008 switch. It’s just what you need! It lets you select individual banks without an option for both, so you won’t accidentally drain both. Great stuff!
Exactly what I was looking for! Appreciate it, man! Sounds like it’ll fit my needs perfectly.
If I connect two battery banks with a switch like this, would their negatives be combined? Just wondering how that works!
Right! I did remove my generator, so the transfer switch will connect to my primary battery. It's nice to know it’s all possible!