Battery maintenance and disconnects

[Kiwi3]

I was thinking for the starter batteries because they seem to draw down over time if you don't specifically pay attention to them. This would cut them out before they could drop low enough that you need to tie the house batteries in to start up. I don't really need it on the house because the inverter/charger can already cut those out at low voltage. DC loads could be pulled from the house batteries beyond that though, but hey - deep cycle. I just hate having my starter batteries pulled down because I forgot to tie the house-starter banks together when I parked. And 3 starter batteries getting pulled down a few times is an easy way to spend $500 on new ones (got the T-Shirt, and the additional $800 expense of replacing a starter on the road, and a set of alternator belts due to a low battery).

[badandy]

Ah I didn't know how you were configured... If you're already taking care of charging the house bank and not really having problems there I would just install an isolation relay between those two banks. This will automatically charge both banks when you have charging voltage applied to either bank, but separates the banks when there's no charging voltage. If you're going to down the road the alternator will charge both banks. If running the inverter/charger it will do both banks. If you aren't charging at all the banks are not combined.

https://www.waytekwire.com/item/8000...ry-Separator-/

One of these things along with maybe removing some loads that are connected to your starting bank that may be drawing current when you're not moving would prevent your issues in the future.

A low-voltage cutoff is a bandaid that will save the batteries from an early death, but it's not the "right" way to do this.