Do you need some fancy huge charger unit or does a trickle charger or standard car battery charger work okay?
Can you install in the deck somewhere a plug attachment for charging like shore power?
Jason

I have seen several set ups where they had a 1000ah starting battery for each engine and a deep cycle for the accessories. The deep cycle battery is connected to one of the engines via an isolator so it will charge when that engine is running.

Jay-A fridge will pull down a 27 deep cycle in 8 hours. I don't use mine unless I'm plugged in. The good news is that if you use a cooler most of the weekend most of the stuff in the fridge is still cool at the end of the weekend. If you are going to use an inverter I would also recommend a dedicated battery. On my boat I have a 27 deep cycle and a 1000 watt inverter that will run everything but AC. I bought a Guest battery maintainer for about 25 bucks and wired it in to that battery. It starts charging as soon as I plug in at the dock. I have also left it on for weeks with no appreciable water loss in the battery. If you go with an inverter keep the battery cables fat and short , the more amps, the better when feeding those things. If you wnat to feed a 600 watt stereo, might as well get a battery for that too. Then another engine to get back all the speed you just lost with all the freekin' batteries

Oh, and try and stay away from isolators-they are very inefficient-battery combiners work much better-or just switch them all.

Insptech, can you expand on the "dont use isolators" comment please. Why are they no good? And what do you mean combiners? I need to get my whole batterey situation dialed in too when I get the new motor put in. My prob. is I seem to always blow up the alternators. I would like to run a battery for just the motor and then two batteries for the stereo. But I would like to be able to charge all the batteries (even if one at a time) off of the alternator.

Sorry Jay to jump in on your thread!!

Tank

Isolators are basically just 2 diodes branching off a single pole. A diode by it's nature has lots of resistance one way and a little resistance the other way. It is the little resistance that gets you into trouble. As charge amperage goes up the resistance in the isolator hampers full flow to the batteries and develops heat(ever notice the heat sinks on an isolator) as the heat goes up so does the resistance and on and on....
So some companies have come up with battery combiners that sense charging and use a relay to route the charge to the batteries. West Marine and others have them out there-they are more expensive than isolators but will allow much more efficient charging. I believe there are some that will jumper the batteries together for emergencies(jump starting)also. This takes the place of the jump solenoid found on some performance boats(Scarabs for sure). If you have been trying to charge 3 batteries with one standard alternator I suspect that is why you keep popping them. I think a high output alternator might be in your future

Thanks Ted I will have to check into the combiners instead of the isolater I'm using. I'm not charging all the batteries at once. What I usually do is play the system but the battery dies then I switch to the other battery....by the end of the day its just alot of strain on the alt. every weekend you know!? People have told me those high output alt. cause more heat and more heat kills alternators too so you are dammed if you do and dammed if you dont!

A HO alternator can build up heat but theoretically it shouldn't work so hard so the heat should stay down. You can also go to a larger pulley and slow it down some for high perf motors while still getting some charge at low speeds.