Charging Two Batteries at the Same Time

I just got a 24v trolling motor and two brand new batteries. I was told in order to get 24v's I would have to connect jumper wire + from one battery to - on the other battery, and then connect by trolling motor leads + on one battery and - on the other. My question is can I charge both batteries in this order as well or would I have to change something.

Thanks mav

Re: Charging Two Batteries at the Same Time

If you have a 12 v charger you would need to disconnect and charge individually or hook them + to + and - to - to charge both at once.

Re: Charging Two Batteries at the Same Time

I do haave a 12v charger, by hooking them up + to + and - to -, how is the charger connected. Do I put both leads from the charge on one battery or do I put say + lead from the charger to one battery and the - lead from the charger to the other battery.

Re: Charging Two Batteries at the Same Time

Either way.

Re: Charging Two Batteries at the Same Time

You don't have to disconnect anything on the 24V battery bank to charge each battery. Connect the charger + & - to the first battery's + & - until it's charged, then place the chargers + & - on the second battery's + & - and charge.

IF you have an onboard charger with independent outputs you can connect the charger to both batteries at the same time, a pair of charger outputs go to each battery, so you can charge both batteries at the same time. (Don't do this with an automotive charger.)

An onboard charger is a good idea with trolling motor batteries as it's one heck of a lot easier to plug an extension cord into the charger and let it do it's thing,,, opposed to dragging the charger out, charging the first batt, then charging the second batt. Batteries left discharged will have a short life span, if it's easy charge them it will get done often, if it's difficult to charge them,,,, they will get neglected. The batteries should be charged as soon as you get home from fishing, not right before your next trip.

Re: Charging Two Batteries at the Same Time

I have 2 batteries powering my boat but not 24V and got a Geust 2 bank charger and love it, it has a recesed plug so you just plug it in and forget it and both batts are always charged.

Check here at iboats, should be @ $120

Re: Charging Two Batteries at the Same Time

I agree that an in boat charger will make your life with this a lot easier. Hook it up to your batteries and when you park the boat at home you plug it in... when you leave, you unplug it. Whether its 2 hours, 2 weeks, or 2 months between outings, your batteries are in good shape and ready to go. I had a 2 bank in old boat that charged the starter battery and 12V trolling battery... was about $100. The one in my current boat charges my starter battery and 2 trolling motor batteries. I think it was about $140. Both were MinnKota and they have worked out great.

Re: Charging Two Batteries at the Same Time

In a 24 volt system, even if you have a single output 12 volt charger you don't need to disconnect or reconnect anything. Leave the batteries alone -- period. Connect the charger to one battery and charge it. When done simply move both charger leads to the other battery. You CANNOT charge two batteries in series AT THE SAME TIME with a single output charger. Paralleling them for this purpose is simply a pain which is why so many bass boats of years gone by had a 12/24/RUN/CHARGE switch on a panel at the bow. It essentially disconnected the series connection and paralleled the two batteries so you could charge them at the same time.

Re: Charging Two Batteries at the Same Time

Question, If I paralleled the two batteries will I still get 24v's to run my trolling motor.

Re: Charging Two Batteries at the Same Time

No, you will get 12v by paralleling the batteries. You need to run them in series to get 24V.

Re: Charging Two Batteries at the Same Time

Two 12 volt batteries in parallel still provides only 12 volts but you essentially have one giant 12 volt battery and capacity is doubled. Two batteries in series are like the batteries in a flashlight -- the individual batteries ADD with each other but capacity is still the same as one battery.