I bought a new trolling motor. My previous motor was a 12v. I bombed up to a 24v 70lb. It's working very well, however, it's time to charge up the batteries. My only charger is a 12v charger. My question is... Can I use my 12v charger to charge the system or should I charge one battered at a time? If I charge one at a time Do I need to remove the jumper while charging?

With a 12 volt charger, you much charge each battery individually. You do not need to disconnect them, just make sure you connect the respective charger cables to the negative and positive of battery 1 and when its charged, connect them to battery two.

I do hope you bought two new batteries and not just one that you are using with an older battery you already had. If you did, it probably won't be very long before the new battery is bad. When connected in series, both batteries need to the same. Same age, same make, same size, approx. the same number of charges on them.

I bought a new trolling motor. My previous motor was a 12v. I bombed up to a 24v 70lb. It's working very well, however, it's time to charge up the batteries. My only charger is a 12v charger. My question is... Can I use my 12v charger to charge the system or should I charge one battered at a time? If I charge one at a time Do I need to remove the jumper while charging?

 

I get the impression that you have used the motor more than once. 

 

Anytime you use the trolling motor, the batteries should be charged as soon as you get home.  Not keeping them fully charged will shorten battery life.

Thank you fellas.  Looks like I will need to 2 bank charger in the near future or this will become a big of a pain in the arse.  

 

Yup I bought two new batteries of the same size and make.

 

I was unaware that leaving them for short time uncharged has a negative effect.  I figured they were rated on charging cycles so I would be better off leaving it for a few 10 hours.  In the future I will keep them charged up.  Thanks for the tip.  

Yes, they have a cycle life, but, discharge level affects that cycle life. Run it down 100% every time and it may last 200 cycles, run it down to 80% and it may last 250 cycles, at 50% discharge it may last over 300 cycles and at 75% it may last 400 or more cycles.

As for letting one sit, 10 to 12 hours is not a problem, it's when one is left discharged below 80% charge for 20-24 hours or more is where the problem starts, that's when the plates start to sulfate, and as they sulfate, they loose charge/discharge capacity.

Great info thanks.

Buying a 3 bank charger was one of the best things I did for my boat. Just get home, plug it in, and forget it. Then all 3 batteries are charged. And I keep mine plugged in all winter to keep the batteries in good condition.

I got a Dual Pro because I couldn't find one bad review on them. Couldn't be happier.

I have 3 batteries and they shouldn't be working yet 2 years later they are. One is a 4 year old Comcast battery, ones a 7 or so year old battery that sat on the concrete floor of my dads garage, and the 3rd is a 5 or so year old Walmart battery. The Dual Charger is a little more expensive but worth it. Not sure these batteries would still be going strong if it wasn't for this charger.

Since I got all the batteries used and for free as soon as one goes bad I'll replace them all.