Converting a 2 bank charger to a 3 bank, Is it Possible?

[blu72nova]

I recently upgrading my trolling motor to a 24V system. I have a 2 bank charger right now (1 for the trolling battery and 1 for the starting battery). Is it possible to convert the 2 bank charger to a 3 bank? Or do I need to buy a new charger? Thanks!

 

[Texasmark]

Re: Converting a 2 bank charger to a 3 bank, Is it Possible?

I doubt it as you would have 3 separate circuits and your charger currently only has 2.

I used my dual on my 24v batteries and periodically (when the boat wasn't used often) recharged my engine battery with a separate portable charger.

Mark

 

[Silvertip]

Re: Converting a 2 bank charger to a 3 bank, Is it Possible?

You need to understand the make up of a multi-bank charger. Those units are like two completely separate chargers in one housing. As such it has two pairs of wires. The key thing is that the grounds are totally isolated from each other. The reason for that is if the charger is connected to a 24 volt system, this is the way it must be as the negative terminal on one battery is connected to the positive terminal on the other. What you are probably thinking is that you want to simply pair up one set of wires and connect them to two batteries. That will work only if you connect that doubled up pair as follows:
One of those two MUST go to the start battery. The second half of that pair MUST go the first battery in the 24 volt pair of batteries. This would be the battery with the ground wire attached to it. The remaining charger output would then go to the second battery in the 24 volt system which would be the one that has the positive terminal feeding the trolling motor. Hook this up any other way you will get smoke and sparks. Also understand that because you have one output feeding two batteries, those batteries will take twice as long to charge as the one with only one output.

 

[Texasmark]

Re: Converting a 2 bank charger to a 3 bank, Is it Possible?

Y That will work only if you connect that doubled up pair as follows:
One of those two MUST go to the start battery. The second half of that pair MUST go the first battery in the 24 volt pair of batteries. This would be the battery with the ground wire attached to it. Also understand that because you have one output feeding two batteries, those batteries will take twice as long to charge as the one with only one output.

I didn't suggest this because he would have to have his start and lower troll batt wired in parallel and that might pose problems for him if the parallel wiring wasn't temporary (for charging only, not knowing his electronics expertise and all. But that is the way my boat is currently wired.

Actually I did away with the second battery (don't need 24 volts with my big troller and light boat and I only had to buy 2 new batteries this time rather than 3) and just run a start and a troll, both wired up in parallel. Since I don't troll all that much, the engine alt can keep them both charged which it does nicely and I have one heck of a starting current....the engine leaps to life. Ha! An the trickle keeps both of them up with no wiring changes/hassle.

Since these chargers ARE completely separate circuits, I thought I'd just wire both my 5a internal chargers in parallel and hook both up to my wired combo of start/1 troll. It worked ok but on topping off, the red/green combo lighting never would finish the charge and go green only. So I took one off line and no more problems.

Mark