[prndl]

Years ago I installed a simple device I found somewhere that would use the existing trailer battery charger and spit the charging circuit to two separate batteries.

I have two 12V batteries that I use via a 1, 2, Off, Both switch. With both batteries off line I want to keep them charged from the existing trailer converter.
I wonder if anyone else knows of the device that will take in the charge line from the converter and send the charging circuit to the battery that is low.

I found dual battery chargers. don't want to go that route.
Found battery isolators, not what I am looking for.

The device I had would sense the battery that was low and charge it and I think after charging that it kept a float charge going to them both until again, one or the other needed a normal charge.

Any ideas?