Getting 12V out of a 24V setup ...

[jrb5789]

I've got a weird one here.

I recently replaced a two bank charger with a three bank charger (Minn Kota). You're typical setup for a 24V trolling motor and the cranking battery. I thought nothing of it, its pretty simple.

So today I got done getting the boat ready to hit the water this weekend and do some fishing. I figured I would check the trolling motor since it seems like everything else was acting up. I was not disappointed. It wasn't working.

-Checked the voltage at the trolling motor: 10V
-Checked the voltage across the series batteries on the TERMINALS: 24V
-Checked the voltage from the (-) to the (+) cable SPADE (not the terminals): 10V

So at this point, I'm figuring I just need to clean my spade connectors. But I did not think it would be that large of a drop in voltage. I took the fuses out of all of my charger hookups so that I could isolate the charger from the batteries, and the voltage went from 10V to 19V.

I haven't thought it all through, but I was hoping somebody may have some feedback or suggestions. I figure my next step is to take the (+) lead that goes to the trolling motor and disconnect it and put the chargers back on the batteries and see what happens.

Any feedback is appreciated. -Jerod

 

[Georgesalmon]

Re: Getting 12V out of a 24V setup ...

I think you need to clean all your connections to every battery including the charger and trolling motor and battery terminals. Then put the charger on and check the voltage at each battery. It should be over 13.7 volts (or more) on each battery when charging, and still 13+ volts when the charger is off.( on each battery) 10 volts is a very dead battery or very corroded connections.

 

[Silvertip]

Re: Getting 12V out of a 24V setup ...

or you wired the batteries or charger incorrectly.

 

[glenn property of pam]

Re: Getting 12V out of a 24V setup ...

what model charger. Most 3 bank chargers are 3 batteries at 12v in any comination on a insulated charger so if you hooked one charger bank over 24v then that could be a problem. The voltage climbed from 10vdc to 19vdc when you unhooked the charger which shows the charger was taking power from the batteries and not adding to them. Another note is that one of the charger banks may be marked as starting battery only as most 3 banks now come equiped with a built in transfer relay.

see if you can work it out or post the model number to see if we can help you

 

[jrb5789]

Re: Getting 12V out of a 24V setup ...

Well all, thanks for the feedback. It ended up being corrosion. I'm surprised that it would have been that large of a voltage drop.