it looks by your picture that you might have a Berkshire.... I wouldn't think you'd already need to worry about replacing your house batteries - if you have the Magnum Inverter/Charger and it's LCD panel, you can push the CHARGER button for several seconds, if memory serves correct, and it will take your batteries into EQUALIZING mode, as long as you are plugged into 50a service.
This is a way to 'balance' your batteries, by the system carefully 'overcharging' them for a set period, usually about 3 hours or so. This brings each battery level with the other, and often times will 'refresh' your battery's outputs, like new!
but, look at your Magnum manual, or this website link, to be sure:
https://www.manualslib.com/manual/53...c.html?page=32
enjoy your Berkshire!