Anyone install 4 batteries in their humvee?

Now I know this isn't required but I was wondering if anyone has done it? Was thinking about adding 2 more batteries in the rear and a equalizer between all 4. The only reason is we get some really cold days here was -20 the other day and while I have a block heater that doesn't do me any good if I decided to drive it to work and have it cool down at -20. I also have a manual glow plug control and all brand new glow plugs but I still need to pull one and test it hooked up to the wiring harness and grounded to see how long it needs to be lit at sub zero temps.

She might start now at -20 but knowing the exact glow plug timing and having more than enough juice to turn it over with ease only sounds like a good thing.

A simpler but maybe more expensive way would be to find a pair of Hawker batteries, they're 1100cca each.

Greg841 said:

A simpler but maybe more expensive way would be to find a pair of Hawker batteries, they're 1100cca each.

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I started my M998 at -17* with two >8 year old Hawkers.

I'm currently running 65 series batteries with I believe is 850 CCA so 4 of those would be 3400CCA vs Hawker's at 2200CCA.

thompsoncustom said:

I'm currently running 65 series batteries with I believe is 850 CCA so 4 of those would be 3400CCA vs Hawker's at 2200CCA.

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4 850 CCA batteries wired in series parallel will be 1700, compared to the 1100 of the Hawkers, but the main issue is the space considerations. 2 6TAGM batteries will fit with no modifications, 4 group 65 will require some type of modification to the battery box, wiring, or other install location in vehicle.

The original 6T battery was only rated around 700CCA, and these vehicles were operated in arctic conditions with them.
It's important that the batteries be in excellent condition, and the vehicle properly set up/maintained for the conditions it will be in.

Coug said:

4 850 CCA batteries wired in series parallel will be 1700, compared to the 1100 of the Hawkers, but the main issue is the space considerations. 2 6TAGM batteries will fit with no modifications, 4 group 65 will require some type of modification to the battery box, wiring, or other install location in vehicle.

The original 6T battery was only rated around 700CCA, and these vehicles were operated in arctic conditions with them.
It's important that the batteries be in excellent condition, and the vehicle properly set up/maintained for the conditions it will be in.

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Thanks for the correction on the CCA as I have no idea just assumed that stacked together.

4 group 65 batteries would never fit under the passenger seat up front but could be spilt between the front and rear passenger side easily. Ya i'm not really sure you need more than 700CCA as I started mine with ease the other day at -10F so maybe it's a none issue but it would put less amperage on the starter from the reduced voltage drop and maybe it would live a longer life?

Anyone add extra batteries for other reasons? lights, electronics, or whatever tho i'm more curious how it turns over in the really cold with 4 batteries vs 2.

thompsoncustom said:

Thanks for the correction on the CCA as I have no idea just assumed that stacked together.

4 group 65 batteries would never fit under the passenger seat up front but could be spilt between the front and rear passenger side easily. Ya i'm not really sure you need more than 700CCA as I started mine with ease the other day at -10F so maybe it's a none issue but it would put less amperage on the starter from the reduced voltage drop and maybe it would live a longer life?

Anyone add extra batteries for other reasons? lights, electronics, or whatever tho i'm more curious how it turns over in the really cold with 4 batteries vs 2.

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The U.S. military operates these vehicles in every operation theater on the planet…to include Artic environment,they don’t add additional batteries .
The Hawker battery is an incredibly robust battery, albeit expensive, they seem to last what seems forever.

Retiredwarhorses said:

The U.S. military operates these vehicles in every operation theater on the planet…to include Artic environment,they don’t add additional batteries .
The Hawker battery is an incredibly robust battery, albeit expensive, they seem to last what seems forever.

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True but you left out the part that the Hawker batteries alone aren't enough in Artic environments and the military has a addon artic diesel powder heater to warm the engine. It is good to know that the Hawker last a long time but 4 batteries would still provide more CCA.

The instruction for the artic heater are Low position from 0 degrees to -25 and High for -25 to -50.

I do see temps in the -20 or more a couple times and year and don't need to drive the humvee on those days but I might look into a artic heater setup as that's the way the military went for the cold stuff and would provide the best cold weather starting.