Is this a good four battery set up?

[roll_tide]

Here is the setup I am thinking of for my 19ft Bay boat. Basically a four battery setup: 1 cranking battery for starting, 2 deep cycles for the 24volt trolling motor, and 1 deep cycle for the "house" battery. The red lines represent the wires connecting the components to the batteries. The purple lines represent the batteries connected to the on board charger. I have a few questions....

1. Should I use a 3 or 4 bank charger? 3 banks would be charging the three deep cycles. 4 banks would charge the three deep cycles and the cranking battery. I guess I would be relying on the outboard to charge the cranking battery if I went with a three bank charger.

2. Battery switch? Should I use the battery switch to switch between the house and cranking battery, and use "both" if needed for an extra boost? I don't see why I would need the battery switch wired to the trolling motor batteries.

3. Should I put these two trolling motor batteries in the front compartment? I have room in the center console for all three but I know the shorter the length the cables run, the better.

4. What should I hook the bilge to? The cranking battery or the house battery?

5. Does the wet cell batteries cause problems when installed in center consoles? I know the emit gases when charging that could be corrosive to all the metal/rubber components above the batteries. The local dealer here says all they install is wet cells and regularly install them in customers center consoles with no problems.

6. What gauge cable should I go with? I plan on using 8 gauge unless told otherwise.

7. Should I just scratch the idea of four batteries and use three?

8. I plan on having an inline fuse for the bilge. Also, a 50amp breaker for the trolling motor. Any where else I need one?

9. Where is the best place to purchase the cables and hardware to attach everything?

The way it is currently set up is 1 "dual purpose for cranking and running all the electronics (gps and depthfinder, livewell, baitwell, nav lights, courtesy lights and bilge pump, am/fm radio...plan on adding vhf to the list) and two deep cycles in the center console for the trolling motor.

I think I am done for now, can't wait to get blasted by the pros on here!

 

[Chris1956]

Re: Is this a good four battery set up?

4 batteries is overkill, IMHO. You do not have anything other than the baitwell and trolling motors that takes any significant power, with the engine off. I would therefore reserve the 2 deep cycle batteries for the trolling motors and baitwell. I would leave everything else on the starting battery. If the motor has a 35A charging system, you might like to set it up with some combiners or isolators to charge all the batteries, the starting battery first. Also, if you can find a good way to do it, you might wire the deep cycle batteries thru a battery switch to allow you to start the motor from them, in an emergency situation.

Put the deep cycle batteries in a battery box to protect the boat from fumes and acid. Charge them slowly. If you run in salt water, I would recommend marine wire. Lets see, 8AWG is good for 30Amps. That should be enough to power your trolling motors. It should also be enough to carry the charger load to the deep cycle batteries as well. For attaching the connectors to the bare wire, a vaporproof crimp is best. Second best (IMHO) is flux, solder and shrinkwrap.

 

[Silvertip]

Re: Is this a good four battery set up?

While I admire the feeling that one cannot have too much power, I'm amazed at the number of people that just this boating season seemed to feel a boat full of batteries must be a good thing. Unless you are a serious off-shore or very big water boater or an overnighter the need for a house battery(ies) is really unnecessary. As was pointed out, you have very few high current draw items and even the bait well can be made energy efficient by using a baitwell/livewell timer switch (runs for 30 seconds and off for three minutes with some of them being adjustable). Not knowing your plans for the boat and your fishing habits, I would agree that four batteries is overkill. If you insist on the four, I would install a switch for the starting and house batteries. Leave the two trollers isolated and charge them via a two output on-board charger. Use a three output if you want to include the house battery. If you want to go overboard on charging as well, get a four output and include the starting battery. But now you have a charger that is almost as heavy as another battery. So my thoughs are the switch, a small battery
"maintainer" for the starting battery and a dual or triple output on-board for the other three. For my boat, it would be a starting battery with a switch to one of the troller batteries for emergency start. Or forget the switch, and just carry a set of jumper cables or a jump start unit and add a dual output charger for the trollers. The engine will take care of the starting battery.