Can you have dual batteries without a switch

[neilbedwell]

Good evening folks! I am new here. My name is Neil and I am from Southeastern Kentucky. I am not a new boat owner but am definitely new to the pontoon world. My wife and I just bought our first pontoon two weeks ago and we couldn't be happier. It is a 2009 G3 Suncatcher 188F with 50hp Yamaha 2 stroke engine. It's small, but we like it. It also has a Minn Kota trolling motor with the factory plug up front to connect it to power. We have it parked at a local lake in a covered slip. Our slip has power available so I decided I wanted to install a battery charger. My boat has dual batteries already.

I purchased a Guest 2611A charger. Here is where it gets a bit fuzzy for me. Like I said, my boat already has dual batteries. I have not yet found a switch of any kind for switching between the batteries. The only switch is a master switch on the dash which turns everything on the boat off with the exception of the motor. It will start and run just fine with that master switch turned off (found that out by accident it seems). Things like the radio and lights will not work with the switch off.

One battery is in a battery box like the ones found at Wal-Mart. The other is out in the open in what seems is the factory tray with a nylon strap buckled across it. The battery in the box has multiple wires hooked to it that run down and thru a grommet into the bottom of the boat. It is quite obvious that this battery has wires connected to it that run back out and connect to the motor (same black wire with white stripe). Like I said, there are many wires on this battery.

The other battery that is not in the box only has one heavy gauge wire running from it on each post. I did not have an electrical meter with me to test continuity between the leads on the battery. I know that's ultimately how I will have to test it to determine if it is a 24 volt system.

Each battery has what appears to be a resettable circuit breaker on one of the wires coming off it. They have 24 vdc written on the side. I did not read what amperage they were.

So, that leads to my questions. Did these boats come from the factory as 24 volt systems? Is that normal or would it be something the previous owner had installed? My Guest charger is capable of charging two batteries in a 24 volt system so I should be OK there. Will the alternator on the boat charge both batteries?

Any tips on where to mount the charger? I looked all around tonight and really can't find a good place to mount it.

Thanks so much for all your help!

Neil

[HandymanHerb]

You need to send us pictures of this and tell us what the batteries are wired too.

The only reason you would need 24 v is for T.Motor, could be they have a Start and a house battery, or they could have them wired parallel it they case it would be 12 v just as lot of amps

Welcome maybe I'll get to boat in my birth State of Ky one of these years

[pond tuuunes]

The batteries should be isolated somewhere, unless for a 24V system. On a 12v system with batteries in a parallel hookup if tgey are not isolated, the weeker battery will draw down the stronger one, and shorten battery life. But, if like said earlyer everything else on your boat is 12V, and your trolling motor is 24v system, it would be a series hookup for your trolling motor. So all negarives on the main battery would be hooked together on the main battery, and all but one of your positives would come from that one, also there would ve a positive from your main battery that goes to the negative on your trolling motor battery. Then on the positive of that battery, it would feed to trolling motor switch, or to trolling motor.

Welcome by the way. JT

[lakerunner]

I run 2. One for motor only and other runs all accessories. I have a dual charger hooked to them.

[neilbedwell]

UPDATE: Went back to the boat this morning. This time I was smart and took some tools. My dad is a retired certified mining electrician (I am an accountant - which means that I've been around electrical "stuff" all my life but I'm the farthest thing you'll find from an expert, LOL). Bottom line, we chased down the wiring and realized that the second battery's ONLY function was to power the 12 volt trolling motor that my boat came with. Nothing more. EVERYTHING else is hooked to the primary battery that is in the box.

We went ahead and hooked the charger up per the instructions for two independent 12 volt batteries. Lights were good and everything seemed to work as it should.

So, now I have more questions:

Is this an optimal setup? i.e. one battery powering ONLY the trolling motor and another battery powering the rest of the boat (I'm going to speculate that the answer is "no")

What would be a better setup for me?

How big of a deal is it to have a battery sitting there exposed to the elements (no box)?

You guys are awesome! Thanks so much for the help!!!

[smltooner]

Welcome to the club.....you came to the right place to ask questions.

[pond tuuunes]

Cant really help you there, maybe one of our fishing tooners can. I am guessing they use seperate systems so that if you kill the trolling battery, the other will still start the main engine? Thats all that makes sense, hope some one can help you. JT

[rockhound]

Thats the way to set it up if you are running a trolling motor, you dont want to kill your starting motor, not a bad idea if you going to be sitting around playing the stereo all day also

[Cycleman07]

I had a G3 and yes they run 24 volt systems...At least mine did with no switch