charging 12v golf cart battery w/alternator

Saw factory installed systems to run accessories isolated from the cranking batteries. See if you cannot find something on 3 plus or + 1 battery systems and copy that.

 

On my 359 Pete with 3 batteries. 2 batteries go too starter. The third battery has a on off switch connected too the two batteries. When off you cannot drain the two starter batteries. Have another on off switch that comes off the third battery that I can turn off so no power too truck. Its just a hobby truck and I don't drive it in the winter. You could do the same with a 4 battery set up. Boats have always had this set up so you can't run everything down and not be able too start engine. Use the on off switches that race cars use. You do have too remember too turn them on and off.

 

3 plus 1 did the same thing with a relay wired to the ignition switch, the manual switches would be easier and less expensive to install. Mixing different type batteries and not boiling the guts out of some of them maybe a concern.

 

If you want to go all the way, get a remote battery regulator. You just wire it to your existing batterys and it keeps the other ones charged.