Install Success - Sears Diehard Platinum Group 31M

DMOZ

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Well, one of my Optima batteries went kaput so I decided to take a stab at fitting the infamous Sears Diehard Platinum 31M. Some people have been successful getting this battery to fit, others have had difficulty. I thought I'd post my experience/thoughts on the getting it to fit properly.

The Platimum 31M has plastic fins that surround the left and right sides of the battery. My guess is that these provide a layer of protection around the battery more than do serve as heatsinks. Anyway, I took the drivers side battery tray out of my vehicle and started playing around with the fitment. I noticed that the fins around one small corner of the battery (bottom, rear, and closest to the fender) were hitting the tray and preventing the battery from sliding in.

I used some wire cutters and trimmed the first three fins on the bottom corner of the battery (see pic). Notice that you only need to trim between 0.5" and 2" of each of these three fins. After that, the battery slid right into the tray like a glove. I reinstalled the battery tray, slid the battery in, made a new battery hold down bar with some aluminum stock from Orchard Supply and Hardware, and voila!!! It's done!

Hope that's helpful for anyone thinking about installing one of these.
Battery.jpg
 
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I installed one of these bad boys in my second tray(passenger side) and it slid in all the way down but it was a tight fit. The only issue I have is the hold down bracket. The stock one doesn't work so I have to fab something up, although this battery is not going to move on me because of thetight fit, I still would lke to immobilize it just to be on the safe side.

-Juan
 

DMOZ

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Oh awesome. I considered it but never really took the time. Assuming it would work for either side but was this on the driver's side tray?

Yep, this was on the drivers side. I assume it would also work on the passenger side, though. Really happy with the results.
 
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I installed one as well. No mods aside from the wires being pretty stretched. Need to still get a retension device made up.

Of note.... this battery weighs about 70lbs. Lots of reserve 200 mins and plenty of CCA to start your rig. Expensive at over $200.
 
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Sears Diehard Platinum Group 31M - ON SALE

I just bought one and thought i would pass this along. Yes the battery is expensive but it is on sale and i thought i would pass the details along. It is normally $249 but it is currently on sale for $239. I was emailed a coupon from Sears (that expires tomorrow) for an additional 10% off (which was $24). So my total out the door (inc. LA sales tax) was $ 237.05. Still expensive, but at least i saved $35 over the normal price.

So here is the link to the battery: DieHard Marine Battery, Platinum PM-1 - Group Size 31M (with exchange)

And just use the coupon code: ExtraTenAug9 when you check out for the extra 10% off.

:cheers:
Sean
 

alia176

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Thanks for the heads up. I did the same thing!

A little trimming to three fins of the battery, as shown above, is all it took. I used simple nylon straps to hold this beast down. Had the straps for few months on other batteries in this location w/o any issues.

:cheers:
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Pathfinder

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I just bought one and thought i would pass this along. Yes the battery is expensive but it is on sale and i thought i would pass the details along. It is normally $249 but it is currently on sale for $239. I was emailed a coupon from Sears (that expires tomorrow) for an additional 10% off (which was $24). So my total out the door (inc. LA sales tax) was $ 237.05. Still expensive, but at least i saved $35 over the normal price.

So here is the link to the battery: DieHard Marine Battery, Platinum PM-1 - Group Size 31M (with exchange)

And just use the coupon code: ExtraTenAug9 when you check out for the extra 10% off.

:cheers:
Sean


I've seen a couple of posts here on mud about folks buying this battery for their cruiser. Am I missing why this and optima batteries are so great? Just curious as to why I should pay 5 times as much for a battery?

Thanks.
 
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Optima batteries suck. Sears Platinum and Odyssey batteries are amazing (I believe some military units uses the odyssey batteries, may be mistaken). Tons of juice to power the various accessories that start to put a strain on a regular old batter. Not to mention the cold cranking amps which give you more use out of your winch etc.

The Diehard 31M is sort of the holy grail of what we can fit in a cruiser tray. It has 1150 CCA for instance. There is more to a battery than CCA, but it's a good place to start

A run of the mill duralast has 500 CCA and costs 80 bucks
 
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The old Optimas weren't that bad. The new ones aren't that great.

If your alternator quits working, you'll appreciate a battery like this very quickly. With 205 minutes of reserve capacity, you can still run your engine (nothing else) for almost 3 and a half hours. Maybe half that with the lights on if it was a night.

A typical battery will be lucky if it can do a fraction of that. The heavier duty construction and dry allow these batteries to withstand off road vibration a lot more and their deep cycle and heavier duty capacity allows them to be drained repeatedly without damage.

A typical cheap battery can only be drained and die a few cycles, before the battery is toast.

And I haven't even touched on winching applications. Just one of these Diehard batteries is equal two typical Optimas (which is what I run) and close to three or even four typical run of the mill batteries.

I don't know much about Diehard or Odyessy, but when it comes time to replace my Optimas, I will definately consider one of these. The only reason I've stayed with Optimas is they keep replacing mine with brand new ones for free everytime they piss out on me, so it's hard to turn down a free battery.

My problelm is that I'd want two of these for my duel battery system and that would get expensive...but talk about piece of mind and reserve capacity! Who would need an alternator, LOL!
 
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two 31Ms is my dream as well lol

that would likely need a spring upgrade or some more spacers on my rig, as these things weigh a ton (75 pounds a piece, so 150)
 
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