83 am General Truck batteries

[wauchsam]

I just got my first am General need to learn a lot. But my first problem is the batteries.
it has Four US 6tmf's, Which are dead, I need to replace them, I need a cheaper way than with the US 6tmf's. Second is I am not understanding why there are four. If the system is 24V it would take two 12V's or 4 6V's But the US 6TMF's are 12V Can someone please explain....

Thanks

 

[Warthog]

Welcome to the site.

First some house cleaning issues. Per the rules you just agreed to you need to edit you profile to list your State of residence. The US is not a state.

Now to your question. Batteries have been talks about for many, many years. Nothing new there. There are hundreds of post covering them.

Most MVs are 24v per NATO requirements. You make 24v by using two 12v batteries in series. 12+12=24

Some trucks need some extra cranking power so the come with two sets of 24v. By wiring them in parallel you get double the cranking power.

What truck do you have? You may not need 4, maybe just two.

I had a M818 that had to have the four batteries. It was so cold natured that two fully charged batteries just wouldn't crank it.

 

[machinist75]

You need 4 when it's cold to start that big ole motor. I run two. Just measure and maker sure the new ones will fit. Get the biggest ones you can.

 

[gimpyrobb]

You have a series parallel connection. Think of it as 2-24 volt batterys in parallel.

You could just get two "8d" batterys(in series) and be done with it.

 

[wauchsam]

Cool Got the Battery understanding, I am not sure what series it is I have no idea where to find it all I know is it is an AM General c525-01285 it has a Cummings 250 6

 

[gimpyrobb]

http://lmgtfy.com/?q=series+parallel+connection#seen

 

[wauchsam]

I paid 3800.00 runs great paint is good it's pretty clean has the canvas and tires are like new
has 43,000 miles has everything but a radio and good batteries starts right up with a jump.

I drove it home

 

[gimpyrobb]

Or this...

 

[gimpyrobb]

You need to be careful running it with bad batterys. That can burn out your alt.

 

[wauchsam]

yeah well I only drove it 3 miles home and now it won't start but it had good Volts on the meter the batteries are dated shipped 2010 but I was told the truck sat around a while and they went dead

 

[wauchsam]

Could I run 4 Group 24 500 CCa

 

[gimpyrobb]

You might be able to charge them one at a time and bring them back, hard to say till you do it.

 

[Warthog]

If you are going to own an MV, three items I recommend everyone to own are: battery charger, battery load tester and a multimeter.

Before starting any electrical troubleshoot you must make sure you batteries are fully charged and load tested. No need to spend hundreds of dollars on new batteries if you old ones are fine and just need charging.

Harbor freight has a loadtester for about $20. I use mine all the time.

 

[Warthog]

You have a M939 series truck. That covers many variants.

Have you downloaded the free tech manuals for the truck? Very important that you at least skim through the Operators manual to know how to start and turn off you truck. If not done properly, it will be a costly mistake.

 

[gimpyrobb]

Thats awful low on amp hours, why not group 31?

 

[Warthog]

Could I run 4 Group 24 500 CCa

No. 500 cca is not enough for the Cummins 250

 

[gimpyrobb]

It could work, but why go with the bare minimum? I look for the highest CCA battery that will fit. As I said before, look for some 8D batterys.

 

[wauchsam]

ok Got me a battery Charger and a load tester via harbor freight Thanks I got two of the batteries out, did notice one thing everything was loose cables mounts everywhere


yes I got the pdf's for op's and maint.


now the adventure begains

 

[73m819]

ok Got me a battery Charger and a load tester via harbor freight Thanks I got two of the batteries out, did notice one thing everything was loose cables mounts everywhere


yes I got the pdf's for op's and maint.


now the adventure begains

If everything was loose, there IS a good chance someone SWITCHED batteries on you.

 

[juanprado]

Welcome to the madness!

Cool truck, I take it was from GSA as I was browsing those but a little far from me....

nice score!