adding batteries

[Jason B]

I currently have 2 batteries (start and radio) both are connected to the altenator to charge with the relay thingy between them to prevent the start batt from draining while playing the stereo.

My question is--how do I add 2 more batteries to the system? Must I COMPLETELY seperate the batteries from the altenator so it doesn't try to charge them? Which, effectively, would mean the stereo would be on its own closed system. Then I would only be able to charge them with an external onboard charger.

Then, how should I connect the onboard charger? One "bank" lead to each battery or one "bank" lead to all three of the batteries?

I really don't want to have to be connecting/re-connecting a bunch of crap everytime I get home

[chpthril]

I currently have 2 batteries (start and radio) both are connected to the alternator to charge with the relay thingy between them to prevent the start batt from draining while playing the stereo.

My question is--how do I add 2 more batteries to the system? Must I COMPLETELY separate the batteries from the alternator so it doesn't try to charge them? Which, effectively, would mean the stereo would be on its own closed system. Then I would only be able to charge them with an external onboard charger.

Then, how should I connect the onboard charger? One "bank" lead to each battery or one "bank" lead to all three of the batteries?

I really don't want to have to be connecting/re-connecting a bunch of crap everytime I get home

What amp alternator does your boat have, this may weigh heavily on whether you build a stand-alone battery bank or just add the 2 additional batteries in parallel with the current stereo battery. You may also want to consider an amp upgrade is plugging a battery tender in at night is not convenient, as it's hard for an alt to recharge even 1 run down battery more less 3.

Adding is actually simple: connect the + and - of both new batteries to the + and - of the current stereo battery. If you want to make it a stand-alone system, just disconnect the current stereo battery's + from the ACR/Iso.

For an On-board charger/tender, just get a multi-stage, 2-bank smart charger. It will have to sets of leads......one goes to the + and - of the starting battery, the other set of leads goes to a + and - on one of the other bank's batteries. They will all charge as they are wire together in parallel. When you're ready to charge, pull out the plug and plug it into an extension cord, nothing to hook up or unhook.

[Jason B]

My boat has the standard alternator--whatever came on it I assume.

What do you mean by "upgrade the amp?"

Thanks Chp!

[chpthril]

Swap it out for a Hi-Output. I'll bet it's a 60A alt

[KonaKing]

I hate batteries