Battery Life?

[rboltz]

Just a general discussion of battery life even though I'll show the batteries from my M-37.

The batteries that came with my M-37 were not replaced during restoration. The cab was not removed although everything else was so the batteries remained in the box although disconnected. You could not see the labels in there. The entire truck was rewired.

Yesterday the truck would not start even though it was on a maintainer. 24.2 volts just sitting there and a drop to 9 volts when trying to crank. My '715 will show 28 volts on the maintainer. Of course it did not crank. Pulled the batteries and was surprised to see the date of Mfg.



1988?? Now I know military batteries are shipped and stored dry so I have no idea when they were "activated". The PO says right before I bought the truck but that seems a short life as I have it 4 years now. Even so, that means the batteries sat 24 years before activation.

So, how long will a "dry" battery last on the shelf? Must be a long time but I would think they will degrade. I used to see these mil-spec batteries for sale on Gov. Liq., the surplus site, as "expired" when only 8-10 years old so that age may be conservative.

Anyway, I'll replace with civilian ones as no need to be "correct" at this stage of my operations with these trucks.

[Don Cavey]

Ron, unless contamination gets into the cell, I would have to believe that a dry charge wet cell (that's a mouthful!) should last a ong, long time. My only thought would be that if the battery were sitting in a wet or humid location, there may be an issue.

I remember activating batteries when I hung out at the local gas station. But that was messy and really, I don't think that we want the average shade tree mechanics having the leftover sulphuric acid sitting around. Who knows where it would be dumped?

Batteries can be a pain for sure. But they're decades better than they were when I was a kid.

[WVcharlie]

I got seven years out of the last set of batteries in my M725. I drive it regularly but I was pleasantly surprised. Normally I expect about four or five years of battery life in civilian twelve volt systems.

[kwai]

I had an Odyssey AGM battery in my ranch jeep that went 10 years. But I used a battery cut-off when it would sit for more than a couple of days.

Generally, I have found that disconnecting the battery from all current draws using a battery cut-off switch makes the batteries last longer. It also helps keep the engine and radiator from filling with crud since there is no stray currents to create electrolysis.

[venominjected]

Always look to find Duralast Platinum AGM batteries.... its the same as an Odyssey or Deka AGM battery with just a different sticker (no really... same case, same factory same everything etc.)....

I had a Duralast Platinum in my 1966 C-10 5.3L LSx swap.... ran my fuel pump, computers, electric fans without issue....sat an entire Wisconsin winter(s) without charger or tender and popped right off every spring.

battery cut off switch I'll second...