Dual vs quad battery packs

[cranetruck]

Some solid arguments for the 4-pack battery systems, please.

My XM757 originally came from factory with a dual battery system (besides the fact that it it's a Ford, engineering figured that two batteries were enough), but a field mod later turned it into a 4-pack.

Why are four batteries needed in most (all ?) 5-ton trucks and ony 2 enough for the 2-1/2 tonners?

Thanks.

 

[rizzo]

I think the trucks with the NTC 250 have 4 batts.

commercial semi trucks have 4 batts too. considering they have 12v that is twice as many as the 5tons. They also have bigger motors.

I don't know why though

 

[5tonpuller]

2 is for the amps to start. 4 i would think would be for a longer crank or drain.

 

[cranetruck]

Thanks, keep it coming, of course we know the multifuels start immediately, if not sooner, still they added two batteries to the original two on the M656/XM757 trucks.

 

[Recovry4x4]

Were there any power requirements for the pershing missle system that used truck power? That's my only thought!

 

[yorkgulch2]

Cold weather starts seem like the best reason for the 4 pack. This is probably not problem in Virginia, but further north the extra juice really helps.
I run dual 12 volts in my pickups mainly for better starting but also for the plow. I believe your amps are reduced about 40-50% at 0 F.
Or it could be the Army's department of redundancy department was involved. You know a HIAB would look pretty good on a m757.

 

[cranetruck]

Re: RE: Dual vs quad battery packs

Were there any power requirements for the pershing missle system that used truck power? That's my only thought!

Yes there were, a separate slave cable kit was provided, but the dual battery set remained the same. May have been a factor later, the TM's from the period all show the dual battery pack with or without the Pershing kit.

 

[nf6x]

Why are four batteries needed in most (all ?) 5-ton trucks and ony 2 enough for the 2-1/2 tonners?

My M543A2 wrecker has 2 batteries, but then it runs almost the same engine as a 2.5-ton.

 

[DDoyle]

RE: Re: Dual vs quad battery packs

The Class 530B and 530C fire trucks on the M44/M45 chassis have four batteries. The TM indicates this is due to the current load imposed by the additional electric systems found on same (most notably the two motors powering the hose reels - but there are additional lights as well.)

I would guess - and it is strictly a guess - that the erector/launcher towed by the 757 has additional lighting to aid in the set up. Perhaps that would be a reason for the additional battery capacity.

Another possiblility - the Fire Truck absolutely, positively has to start on the first try - no casual slaving is an option. Simillarly, given the intent of the Pershing Missile system that the Ford 8x8s were used with - slave starting was not an option - in the event of nuclear attack they needed to move out right then. Remember, this is an era when we kept SAC ready to go 24/7 - I bet the Pershing crews were too.

My .02,
David Doyle

 

[BKubu]

I am not sure of the complete history of the four battery set up, but I know they began to use it religiously on the M809 series trucks with the NHC-250. If you have ever tried to start one up in the cold you know why. It takes a lot of juice to crank those 855 cubes when they are ice cold. I always hit my trucks with a sniff of ether when it is cold, but, when I got my first 5 ton M813A1 in 2000, I did not know enough to do that. Below freezing, you will be lucky to get two minutes of cranking time (which translates into about 4-5 tries to start the beast...at about 20-30 seconds of cranking each time). By the 5th time, the engine was turning over slowly to put it mildly. Anyway, they carried the same basic motor into the M939 series trucks and kept the four battery set up. Then, when they switched to the 6CTA 8.3 motor in the M939A2, they kept the four batteries, although I have been told (and seen) that this motor really only needs two batteries since it is only slightly larger than the LDT/LDS motor (506CI vs. 478CI). I have no knowledge about the latest 5 tons so I am unsure what they are doing with them as far as batteries are concerned.

 

[M215]

Cummins 250?

Hello SS,
Can you start / run the 5 tonners with the NHC 250 on only two batteries in warm climates? I'm waiting to purchase one from GL and was wondering if the purchase of four batteries was necessary.
Thanks, Karl

 

[groundog]

I have a 813-a1 and run two batteries---but then I am in Aizona----two 900 amp batteries---

 

[DaveP]

Re: Cummins 250?

Hello SS,
Can you start / run the 5 tonners with the NHC 250 on only two batteries in warm climates? I'm waiting to purchase one from GL and was wondering if the purchase of four batteries was necessary.
Thanks, Karl

I dont think it would be a problem in warm places.

 

[timntrucks]

RE: Re: Cummins 250?

on my m816 with the nc-250 it came with 4 batteries but i havnt had it in cold wheather yet, starting that is. there is a pre heater on mine and i think it works. the light works anyway. the two bat system is alot cheaper to buy.

 

[cranetruck]

RE: Re: Cummins 250?

So it's based on current needed for cold weather cranking. Makes sense. The upgrade to a 4-back on the XM757 must have applied to the Pershing missile only, no reference shows it needed for the other versions of the 8x8 trucks.

Guess they can get away with dual batt systems in the desert if they wanted to save a few bucks on the 5-tonners.

 

[jwaller]

RE: Re: Cummins 250?

my 818 has 4 and even in warm weather it needs them. nhc-250 eng

 

[Gamagoat1]

My 816 has two batts.
I'm in Colorado so it gets cold now and then. I, too, give it a sniff of ether when it's cold.

 

[loslobos11]

I am in Maine, even with a snort of ether, in cold weather 4 batts are something I have to have with the NHC250. It is a lot of motor to crank over, but with 4 batteries and ether I know it will start in the coldest weather....would like a blockheater though...

 

[Gamagoat1]

The block heater is a big help when temps get low. It takes a while to warm up tho.

 

[Cdub]

I do believe that it comes down to cranking amps. when trying to
turn over an 855 cubic inch engine during the winter months.

you'll find that most batteries are rated by cold crank amps.

A quad battery set up would be standard for most all climate
condition except in extreme regions where addition options
would be required like a block heaters.

Even in NJ during the winter months plugging in any diesel
will always be to your advantage.

Cheers,

C'dub