Charging 24 volt trolling motor

[1simplemann]

 I graduated to boat ownership after a life time of canoes and kayaks. I'm new to this kinda stuff. So I'm prepping the boat for my trip to Fort Peck. Charged the outboard batteries. Then I look at the trolling motor batteries. Not sure what i'm looking at. Are they in series or parallel? Where do you hook the leads? Hot wire comes from trolling motor to positive. From the negative, a wire goes over to the positive of the other battery then  the black goes from the negative of that battery to the trolling motor. Don't want to make a mistake.

[Ohio Archer]

Your batteries are hooked up in series...12v + 12v = 24 v.  If your charger is 12v then hook it to one battery to charge it (red to red, black to black).  When the first one is charged then move the charger to the second battery.  If you have two chargers, hook them up the same way at the same time (one charger per battery).  One charger is going to take a while to charge both batteries and they both need to be charged equally.  Don't fully charge one and only 1/2 charge the second.  Better to use two separate (identical) chargers or get a 2 or 3 bank (to charge the starting battery) onboard charger to charge them.

[1simplemann]

That's what I thought. Thanks. Since they're jumpered together won't the 2nd battery charge as well?

[EllisJuan]

2 hours ago, 1simplemann said:

That's what I thought. Thanks. Since they're jumpered together won't the 2nd battery charge as well?

No.

[S Hovanec]

4 hours ago, 1simplemann said:

That's what I thought. Thanks. Since they're jumpered together won't the 2nd battery charge as well?

No.  Only if they were parallel would both charge from one charger.

[Ohio Archer]

5 hours ago, 1simplemann said:

That's what I thought. Thanks. Since they're jumpered together won't the 2nd battery charge as well?

Only if you were using a 24v charger.  If you were to hook up a 12v charger to the (-) of one battery and the (+) of the other battery it would probably burn up the charger and hurt the batteries.  Here's a good reference...page 5 has your (and my) setup.

http://www.nyc-arecs.org/batt1.pdf

[Further North]

Your best solution is to get an on-board charger - I'd go 3 bank - so all you have to do is plug it in at the end of the day.

[1simplemann]

So after further inspection, My SnL noticed what appeared to be an inverter tucked behind the batteries. It's hard to see under there especially for a guy without his glasses. This got me to thinking. Why would there be an inverter by the batteries? Then it hit me. That's not an inverter but an on board charger! I started looking for a plug by the bow which is where the plug has been on every boat that an on board charger that I've ever been in. No plug? I go back to the battery box and start looking in there w/ a flashlight. Wa La! All coiled up, tucked out of sight was the plug cord! I plugged her in and we're good to go, except I just realized the wife turned the garage light off which is the plug the boat is hooked up to. Could have been bad since we're leaving tomorrow. Thanks for the help. I post pic's when we get back.

[GetJigginWithIt]

Sweet find. Like finding a dollar bill in your coat from last winter after you put it away.