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Author Topic: need new Chassis battery - what does the "MHD" stand for?  (Read 369 times)

Mike Shumack

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need new Chassis battery - what does the "MHD" stand for?
« on: May 19, 2019, 03:30:17 PM »
I have a bad Chassis battery. I'm going to replace both. The '05 Patriot Owners manual says the Chassis batteries are "31P-MHD 950CCA and 195RC". The "P" is for post terminal (it appears), so I guess the previous owner changed the cables from post style to stud style at some point.  I have 3/8" stud terminals on all my batteries which I think is a better terminal connection method.

So looking for best pricing, I see the "Interstate" 31-MHD, Group 31T (950 CCA, 195 RC) for $166 each. And Sams Club has "Duracell" brand model 31C for $110 each (with same specs).

I know the Interstate brand is top of the line.
I don't know anything about the Duracell brand (other than the small AAA batteries). Does anyone have experience with Duracell group 31 batteries?

Also, what does the "MHD" stand for. I looked at a bunch of battery type charts and could not find MHD listed.
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

David T. Richelderfer

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #1 on: May 19, 2019, 03:40:26 PM »
In Smart cars, MHD means Micro Hybrid.  Could be?

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Mike Shumack

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #2 on: May 19, 2019, 03:42:05 PM »
 ::)
ha. I don't think so - my coach is pretty dumb.
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

Bill Lampkin

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #3 on: May 19, 2019, 03:44:47 PM »
From Interstate battery chart, MHD means Mega Heavy Duty; Whatever that means!
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

Bill Lampkin

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #4 on: May 19, 2019, 04:01:46 PM »
Here's the Interstate size chart with the MHD 'definition'. For the two batteries with the MHD designation, they appear to weigh more (more lead, more capacity) than their siblings.

http://www.clarkegen.com/Libraries/PDF_Files/Specification_Sheet_-_Batteries.sflb.ashx

2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13
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Mike Shumack

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #5 on: May 19, 2019, 04:10:52 PM »
Hi Bill. I see now that MHD is = Mega Heavy Duty (sounds like a made up term). 

That MHD battery is listed as a "31P" (from what I can tell from picture of battery that is a "Post" terminal).

Since I need a "Stud" terminal, I guess I need the 31-MHD (which listed as a "T" style).

Nice how the warranty drops from 18 months for the 31P-MHD to 6 months for the 31-MHD.
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

Gerald Farris

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #6 on: May 19, 2019, 04:11:36 PM »
Mike,
The only thing that I have ever heard of with the acronym of MHD that could be associated to a battery is magnetohydrodynamic, which is the study of electrical conducting fluids like the electrolyte used in a battery. Personally, I would disregard the MHD when looking for a replacement battery, but be sure that they meet the minimum CCA rating.   

If your owners manual states that your coach came with post style chassis batteries, it is wrong. Your coach came with 3/8 inch stud connections on the OEM batteries.

Gerald
« Last Edit: May 19, 2019, 04:35:18 PM by Gerald Farris »
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Mike Shumack

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #7 on: May 19, 2019, 06:51:35 PM »
I just finished installing two new Chassis batteries. I got two Interstate 31-MHD (950 CCA 195 RC) which meets the original specs of the coach.
I'm glad the battery failed in my yard rather than on the road. That's the way it's suppose to happen.

BTW - with one bad chassis battery i could not start the engine even with boost switch held (it cranked a little, but too slowly and not enough to start her). So boost switch is just that, a "boost", and not a backup system for a failed chassis battery.
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

Mike Shumack

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #8 on: May 19, 2019, 08:25:20 PM »


If your owners manual states that your coach came with post style chassis batteries, it is wrong. Your coach came with 3/8 inch stud connections on the OEM batteries.

Gerald

The Owners manual just says the batteries are "31P-MHD" and gives the CCA and RC specs.
I made the assumption the "P" stands for Post Terminal from looking at a picture of a 31P-MHD on the Interstate website which shows post terminals (but that photo of a 31P-MHD could have been an error too).
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

Bill Lampkin

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #9 on: May 19, 2019, 11:39:28 PM »
Had the Beaver in the shop (Cat dealer) last spring and they replaced the chassis batteries w/ 2 CAT batteries; pretty sure they are 950 CCA like those you found. The batteries were $130ea, not bad, but boy did he hit me for the labor to install!
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

Roy Boles

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #10 on: May 20, 2019, 04:40:27 AM »
I installed a set of the Duracell chassis batters from Sams Club. Working fine, no problems so far.
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Jim Nichols

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #11 on: May 20, 2019, 06:03:54 AM »
We installed CAT batteries rated at 1000 CIA 2 years ago. CAT dealer took the old interstate's for cores bringing the price down.
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Fred Brooks

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #12 on: May 20, 2019, 02:04:48 PM »
    Hi Guys,
Not really sure what the acronym stands for, But I can tell you this. It has to do with how the battery cables attach to the battery. On Interstate batteries it is a threaded post instead of a lead post for a typical battery clamp.
Fred Brooks
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George Harwell

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #13 on: May 20, 2019, 03:39:29 PM »
Mike,
        Replaced my Interstate 31-mhd 2 years ago. They were only 14 years old. Dealer said it was a record as the oldest he had seen was 12 years. The solar panel keeps them from discharging. I also like sealed battery, no servicing, just keep them clean. You made a good choice in my opinion.
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Joel Ashley

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Re: need new Chassis battery - what does the "MHD" stand for?
« Reply #14 on: May 20, 2019, 09:27:55 PM »
George, I don’t know that I’ll quite overtake you yet, but my (threaded post) 31-MHD’s are now just at 13 years. 

The house set (U2200’s) started giving up last year at 12 yrs.  I’ll get new Interstates at Costco all-around just before we finally are healthy enough to resume our travels.

Joel
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