12v trickle charger / 24v M38

[93vetteguy]

My 1952 M38 has the 24v system and the batteries will not turn over the engine. It will not start. They need to be charged and presently I only have one 12v trickle charger. Question! can I just hook up the 12v charger to each battery separately and charge them like you would a typical 12v car? I was hoping to charge each battery one at a time and not have to remove them from the M38. I currently do not have the 24v slave receptacle as my jeeps MC number is greater than 47771. It would be nice to have it set up like RickG's (battery tender 1/3!13) and took a 24v trickle charger to the slave. I guess I have been spending my free time working on the jeep and not driving it. My hope is to keep the the jeep running as long as I can while doing the restoration. Thank you for your advice!

[wesk]

Sooner or later the wise move is to obtain a 24 volt charger to keep life simple.

The cheap move is to disconnect the cable that connects the engine compartment battery's + post to the cowl battery's - post at the engine compartment battery. Then each battery is now a single isolated 12 volt battery and charge them individually.

The other wise move is to make certain you have no current draw on the batteries when all switches are off. To test for this problem you disconnect the engine compartment battery's negative cable and connect a 24 volt lamp between the disconnected cable and the negative post. If the lamp glows you have a current draw somewhere that is not suppose to be there. You will have to do this test one circuit at a time until you find the offending circuit. The most common culprit is the starter kick switch.

Another trait of lead acid storage batteries that are wired in series is for the two batteries to chase each other. Over long down periods this can result in both batteries discharging themselves even though only one battery is the weak one. This is why both batteries should always be exactly the same models and purchased together as a pair.

Finally a simple and cheap form of protection from battery current leakage through the jeep while it sets unused is the installation of a $5.00 battery cutoff switch on the engine compartment battery's negative post.

[oilleaker1]

Yes you can simply charge each one. They also recommend swapping them because one will drain faster than the other. I disconnect the dog bone in between when I charge. The dog bone is short on a M38A1 AND LONG ON A m38 . The frustrating part is it seems sooner or later one of the two batteries will die off and cause problems starting and the other is still good. I usually take a test light and look at the brightness of each after they have sat for a few days and it will show itself. Batteries are my # 1 irritation. Gas and tires are easy compared to batteries. John

[oilleaker1]

Wes is a faster typer than I------ John

[chrisk]

Insert a Battery Disconnect Switch between the batteries, turn the black knob a half turn to the left and the batteries are separated.
Even if you do not use the jeep long time, it is easy to disconnect the power between the batteries.
Along the way you have an additional theft protection, remove the black button.
Chris

[wesk]

By using the device between the batteries you do have the convenience of charging them with a 12 volt charger independently but you also introduce a source of increased resistance between the batteries as the surfaces of the disconnect start to corrode. This imbalance will add to the issue of the batteries chasing each other down when one battery (the closest to ground usually) discharges itself over time faster than the one removed from it's ground.

[93vetteguy]

Thanks everyone for the helpful info.

[chrisk]

Wes, you're right, there are some negative points, but you have no use a wrench.
Chris