I’m planning to install a MP ll 2x120 but have very limited room for batteries, and everything else. At least for the AH that I’d like to have. Can I use two different AH batteries if they are both 12v and lithium and same brand? There are two sets of battery terminals on the bottom of the MP unit, can I use one set for say a 600AH and the other for a 300AH to give me a 900AH system? Because I’ve heard you can’t parallel different AH batteries? Does that work? Thanks!
Discuss that with the battery manufacturer that you plan to use. Some manufacturers allow it, some don’t.
in theory you can use batteries of different capacities in parallel - provided they have the same voltage/charge characteristic. i.e. they have the same chemistry. You also need to make sure that the larger battery can carry the total current of the multiplus, and the smaller 50% of that current.
For the connection to the multiplus, using an external busbar would be better than paralleling on the internal connections - these are expected to share current equally.
Thanks, guys, for your quick reply and advice. I’ll probably just stick with the one larger battery for ease of use and configuration.