Can anyone give me the low down on 12/24 volt battery chargers. I have a 24 volt trolling motor with two 12 volt batteries running them. I also have two 2 bank on board battery chargers, I am charging 4 batteries in my boat. what I have been doing is disconnecting the negative to positive wire between the trolling motor batteries to charge this system. Is this the correct way to charge these batteries? They don't seem to be charging to full capasity every time I go out. Seems like sometimes they do fully charge and sometimes they don't. any suggestions?

msivey
just leave your trolling motor battery wires alone. do not disconnect any wires from the batteries. if you did return them to the original factory setting. now all you have to do is connect your charger to your batteries and turn on your charger. they should take a full charge now if you haven't built up a memory. rust a reminder to always charger your batteries after every trip. hope this helps any other question please feel free to write or email me. scotty

Since you didn’t get very specific I’ll give you the standard fifty cent schpiel I give a new boat owner..

Shaf is 100% right about disconnecting any wire, it is totally unnecessary as the battery chargers are two bank, charging each battery on a stand alone basis.

I don’t know what type or brand of charger you have but I can say from experience that many units commonly available commercially for this purpose simply don’t do a proper job of charging deep cycle high capacity (DCHC) batteries.

While they do resemble Automotive batteries they are not, the inner construction is different in some important ways that I won’t go into here, but it is enough to say they need a different charging cycle than you truck battery.

I use the ProCharger, Sportsman, 10-10-10 three bank. It gets plugged in as soon as I park my boat, and unplugged just before I take off the next trip. Whether overnight or a week later. One of the advantages of this particular unit is its ability to shut completely off when full charge is reached. (Float Voltage for a DCHC battery is 14.7 - 15 volts according to most battery manufacturers). And restart the charge cycle if the battery discharges enough to require it. All liquid lead-acid batteries self discharge at some rate, most can be considered at least partially discharged if left sitting for more than 30 days.

I consistently get three or four years out of a set of TM batteries.

I charge them as soon as I can.
I check the water in them at least every two weeks, more often during hot weather when used heavily.
I use Distilled or Osmotically filtered water to top them off.
I keep the batteries and terminals clean and tight, with a coating of anti-corrosion compound.


I use Group 29 batteries instead of G27whenever I can. They have a lot more capacity, they don’t get stressed as much under high load cycling. I’d like to go to G31's, but they won’t fit most battery compartments, they’re heavy, some weigh as much as 90 pounds.