How can I recharge a 2nd 24V battery in my boat while running the motor with my main battery?

Question

I have a Deep Cycle 24V marine battery for craking, running the boat, etc. I just bout a 2nd battery for my trolling motor. I want to be able to put a charge on that 2nd battery while I am running the motor (cruising, finding new spots, etc). How can this be done?

Thanks in advance!

Answer 1

Hook them up in a parallel circuit.

Answer 2

im not sure if you can daisy chain because you might burn the boats electrical up or get a solar charger and connect it to the trolling battery. it wont put much of a charge but will keep it alive.

Answer 3

Another option to the above is to set up a second 24 volt bank with a switch to change over from one to another. Then you have 2 sets of 24 for emergency as well as splitting a single off to run your troll, and a second single for the added time. Easier to wire than trying to isolate a 12 volt bat. on a 24 volt system. You just need a switch. There are electronics to separate a 12 and 24 and allow charging for things like marine electronics but the cost is right up there.

Answer 4

Buy a battery isolater switch from your local marina. It will allow you to connect both batteries and you use the switch to choose between Bat 1, Bat 2, Both, or Off.

Answer 5

There are two basic problems with this set up. First of all, if you are running an outboard, they usually have a 5 amp or 10 amp alternator, so it takes a lot of running to recharge a trolling motor. Second, if you wire them in parallel, you will be using both batteries for cranking, running the boat, etc.

You should isolate the trolling motor off from the other battery by installing a diode on the positive cable to prevent this battery from putting out juice to running the boat, cranking, etc.

If you have an inboard or an I/O check the alternator to see what its output is. It may be sufficient, or you may be able to get a higher output one.

However, it is probably better to use 110 V AC to a battery charger to charge up your trolling motor on a routine basis.

Regards,

Dan