New M923, battery issues. . .

[Entropy455]

We jumpstarted my M923 at the Fort Lewis DRMO, using another M923 that did not have dead batteries. We drove my truck onto a 30-ton tilt-bed trailer for the trip home. The batteries that were installed my truck (NATO part numbers) will simply not hold a charge. They are sealed lead-acid batteries, and were manufactured in late 2010. The stock configuration has (qty 4) of these batteries in a series-parallel configuration.

Correct me if I’m wrong, but isn’t this a bad way to connect batteries? I.E. there’s no battery isolator, and the batteries will drain themselves via the closed loop. Perhaps that’s why the truck is marked “check batteries daily”, and why my batteries were drained so dead, that they'll never recover.

Anyway. I pulled out the NATO batteries, and installed two 12-volt deep-cycle/starting batteries (500-CCA each) - about the size of a 60-lb pickup truck battery. These batteries "almost" had enough guts to turn over the engine. Needless to say - not enough cranking power to start it.

So I purchased two new commercial truck batteries that fit perfectly in the battery compartment. They are NAPA part number 7271. They are 12-volt vented lead-acid, weigh about 130 pounds each, and are each rated for 1750-CCA. The truck immediately starts with these batteries - with zero hesitation.

I took the truck for a drive, and it runs great!

 

[nf6x]

Congratulations on your new truck!

That black text is hard to read on the forum's green background.

 

[Entropy455]

I asked nicely, and Napa lowered the battery cost to 204 dollars each. That was the best price they could give me.

There was also a 50 dollar core charge per battery! Thankfully they took two of the old NATO batteries as cores.

I'm pretty happy with this truck. It's a 1984, M923, and I paid $4000.89 out the gate. Additionally, I paid a guy 550 dollars to haul the truck home (about 50 miles).

Now I have to convert my equipment trailer over to a Pintle Hook!

 

[juanprado]

You got quite a deal on the battery cores. A 6tl core is not the same as a 8d battery. They are almost half unless you had to pony up all 4 then it would be square.

Congrads on your truck and you need to post pics.......

 

[nf6x]

That sounds like a good price on your truck!

 

[Entropy455]

The best vehicle I ever purchased, was an old US Navy Shipyard Forklift.

It came in quite handy today for installing those 130 pound batteries! I lifted them up level with the battery compartment, and basically slid them into the truck.

I was also wondering about the core charge. It takes two of the stock NATO batteries to equal the weight of one Napa 7271 battery.

I'm not sure what lead is fetching now, but a few months ago it was fetching 55 cents per pound!

I think I'm going to store the last two dead batteries as just-in-case cores. . .

I'll post some pics this weekend.

I REALLY like this truck!!!!!!!! I took my wife for a ride, and I told her it's like being in the Army, without actually being in the Army! (then I got the look. . . .)

I served 8 years US Navy on Submarines, and I never got to drive anything bigger than the duty vehicle, I.E. a 1-ton passenger VAN.

 

[renovate7]

I used the 2 group 24 batteries out of the Deuce to start my new 925 and move it around. They seem to fire it right up. I'm going to get 2 new batteries for the 925 and am most likely looking for 1000ca. I'm not going to put 4 batteries back in, here in FL we don't get the cold weather.

 

[crownjewel4]

Pictures

We jumpstarted my M923 at the Fort Lewis DRMO, using another M923 that did not have dead batteries. We drove my truck onto a 30-ton tilt-bed trailer for the trip home. The batteries that were installed my truck (NATO part numbers) will simply not hold a charge. They are sealed lead-acid batteries, and were manufactured in late 2010. The stock configuration has (qty 4) of these batteries in a series-parallel configuration.

Correct me if I’m wrong, but isn’t this a bad way to connect batteries? I.E. there’s no battery isolator, and the batteries will drain themselves via the closed loop. Perhaps that’s why the truck is marked “check batteries daily”, and why my batteries were drained so dead, that they'll never recover.

Anyway. I pulled out the NATO batteries, and installed two 12-volt deep-cycle/starting batteries (500-CCA each) - about the size of a 60-lb pickup truck battery. These batteries "almost" had enough guts to turn over the engine. Needless to say - not enough cranking power to start it.

So I purchased two new commercial truck batteries that fit perfectly in the battery compartment. They are NAPA part number 7271. They are 12-volt vented lead-acid, weigh about 130 pounds each, and are each rated for 1750-CCA. The truck immediately starts with these batteries - with zero hesitation.

I took the truck for a drive, and it runs great!

Can you post pictures of the new batteries, and how you hooked them up. I have, what I believe is the same problem with my M923. Batteries will not hold a charge, circa 2010, look brand new. Jump started at Fort Meade, drove home 5 hours, turned off, still dead.
Would like to see how you hooked up terminals now, from the 4 battery set up, to the 2 battery.
Much appreciated. I will have my M1009 going this week, want to slave start the M923, and figure out if it is a battery issue or something else once I put meters on.

Thanks much,

 

[crownjewel4]

M923

PM or post pictures directly.

Thanks much,

 

[Jared]

I have the same battery just from a different manufacturer: Deka 908D. They are big. Have an M813 and it cranks it really well. I had to put the Battery Minder on for a couple of days earlier this month because I haven't been driving it enough. After that they're just like new.

 

[jcappeljr]

I never put 4 batteries back in.I have had over 30 5-tons.I always put 2- batteries back in.Yes 4 -batteries will give you better starting in cold weather.2 batteries work fine for me in Pa.

 

[crownjewel4]

M923 pictures

Can anyone post or PM some pictures of the 2 battery conversion. Just want to be sure I get the wiring correct. I currently have 4 battery set up.

Much appreciated.
Thanks,

 

[crownjewel4]

Pictures



Any pictures??

 

[Stein12501]

I had to replace my batteries with 2 Optima batteries. I will try to attach pictures. On mine I have one 24v ground and one 12v ground for the heater. It shows it in the TM's.

 

[Eddiejj]

I currently have two dead NATO batts in my M923a1. So I buy to 12 volts with high cranking out put and follow the plus and minus and I should be good to go? What I read was there is some thing else I am supposed to connect for the 12 volt batteries? Thanks Ed.J

 

[juanprado]

In Pa, you might need all 4 bad boys to crank in cold weather.

Deka makes the 6tl and they are in Pa. Also O'reillys sells them by special order.

 

[trooper632]

I put two WalMart batteries in all of my trucks, never have had a cranking issue, 3 year exchange at any Walmart in any part of the country.

 

[Bighurt]

I put two WalMart batteries in all of my trucks, never have had a cranking issue, 3 year exchange at any Walmart in any part of the country.

When I recovered my M925 I bought two walmart cheapo's, they are puny. Still in the truck...

 

[tobyS]

Here is a picture of the 1400 cca 8D in my 923 and 817. This is the easiest of systems to connect. They go in series since it is 24 volt. ALWAYS clean the terminals on both ends as they are known for building up an insulation layer. Do a search and you will find numerous posts on battery connection if you need it.

 

[Rifleman]

Just a question, did you happen to try a very slow, deep charge on your 6TL battery's before you traded them in. The reason i ask, when i got my truck, it had gone through RRAD in 2009, they installed 4 new 6TL battery's. My truck only had 36 miles, and 6 hours of use since the RRAD overhaul . The problem with my battery's, almost all of the cells were low on water, and would crank the engine over one or two turns before stopping, i guess that's what happens when you leave a truck sit for 3 years without use.


Another member here told me to first try a slow deep charge before i spent any money on new ones. I said, what the heck, saving money is always a good thing. It took me over a day each to charge them up, and by doing the slow charge i was able to save all 4 battery's. After i had them all charged up, i bought one of those solar panel chargers that the military uses on Hummers. Now if you watch the "parts for sale" section, they pop up from time to time, for right around 140 bucks or so. Since installing that solar charger, i have not had any problems with my battery's, every time i press the button on the solar charger to check the state of charge on my battery's, they show 100% charge., it doesn't get any better then that. YMMV