Replacement for the Sears Diehard Marine Platinum Battery

Electrical and electronic topics for small boats
jimh
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Replacement for the Sears Diehard Marine Platinum Battery

Postby jimh » Sat Mar 26, 2016 1:24 pm

As noted elsewhere, the USA retailer SEARS is no longer selling a battery under the designation Sears Diehard Marine Platinum. As previously discussed, those batteries were believed to be a private branding of the Odyssey battery made by ENERSYS in Missouri.

A possible replacement battery in GROUP 34 size is the NORTHSTAR NSB AGM 34M battery. The MSRP of the NORTHSTAR NSB AGM 34M battery is $345, but it can currently be found on-sale at their on-line web shopping site for $295.

A similar battery in GROUP 31 size is the NORTHSTAR NSB AGM 31M battery. The MSRP of the NORTHSTAR NSB AGM 31M battery is US$ 435, but it can currently be found on-sale at their on-line web shopping site for $380.

It is believed that the retail chain BATTERIES+BULBS is also selling these NORTHSTAR batteries under a branding of X2POWER, and they are also having a promotion at this time. The 31M battery has a regular price is $380, and there is a 10-percent price reduction offer if you order on-line and pick-up at a local store. This appears to be the lowest price for the 31M battery.

It is also believed that some batteries sold at CABALA'S under their branding are made by NORTHSTAR Batteries.

The NORTHSTAR company is a privately-held Swedish battery manufacturing company which was founded in 2000. They have two primary product lines and manufacturing centers. For telecommunication power systems, NORTHSTAR has a manufacturing facility in Sweden. For manufacturing lead-acid batteries, NORTHSTAR has a manufacturing plant in Springfield, Missouri, USA.

The absorbed glass mat lead-acid batteries made by NORTHSTAR utilize 99.9-percent pure lead material for the positive plate. Although for a long time there was a widely held misconception among boaters that the AGM construction technique itself accounted for the lower rate of self-discharge from AGM batteries, it is now better known that the purity of the lead used in an AGM battery is responsible for this advantageous feature. NORTHSTAR explains this in their FAQ:

Why can AGM batteries sit so long without needing charging?
Higher impurity levels are one item that can greatly accelerate self discharge and shorten shelf life. The high purity lead used in the NorthStar grids and plates contain very low impurity levels giving it very long shelf life characteristics.


The battery manufacturing facility in Springfield, Missouri is reported to have a production capacity of about 1.8-million batteries units per year. In the USA, the most significant deposit of lead is located in the Missouri area, which may account for the location of a lead-acid battery manufacturing facility in that region.

NORTHSTAR also sells batteries to EXIDE, who then markets them under their branding. It is clear that NORTHSTAR is one of just a few actual lead-acid battery manufacturers in the USA. These limited number of manufacturers supply many retailers with private label branded batteries, as discussed here.

Note that ENERSYS continues to manufacture and offer lead-acid marine AGM batteries under their ODYSSEY brand, using their Thin Plate Pure Lead (TPPL) technology and absorbed glass mat (AGM) contstruction. The 34M-PC1500 and 31M-PC2150 ODYSSEY Extreme Series Marine Dual Purpose batteries are still available via their on-line store and elsewhere. On-line the 31M battery sells for $403; the 34M battery sells for $302. The ODYSSEY website offers free shipping in the USA. This makes their prices quite competitive with NORTHSTAR.

Unfortunately, none of these sources have pricing as low as SEARS was offering on their private-label versions. For some time one could buy a Sears-brand battery of these general specifications for about $230 to $260. The pricing from these actual battery manufacturers and their retail partners runs about $100 more.

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John_Madison CT
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Re: Replacement for the Sears Diehard Marine Platinum Battery

Postby John_Madison CT » Sat Mar 26, 2016 2:44 pm

I get group 29 deep cycle batteries from Advance Auto for around $90. Regular, reliable lead acid. I don't see the real gains going with these expensive ones.

jimh
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Location: Michigan, Lower Peninsula
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Re: Replacement for the Sears Diehard Marine Platinum Battery

Postby jimh » Sat Mar 26, 2016 5:17 pm

If you can buy a pure-lead AGM battery with the same specifications (1,000-MCA) as Sears Diehard Marine Platinum Battery in Size 34M or 31M for only $90, I am sure everyone would like to have more details. Please give the manufacturer, model, and all specifications. At $90 retail that price would be only one-third of the Sears battery price, which, as seen above, was at least $100 less than comparable batteries from other sources. Let's have a pointer to the details and a vendor. Thanks.

I don't want to pay any more than necessary to get a pure lead AGM battery 1,000-MCA battery from a quality manufacturer with ratings that match the Sears Diehard Marine Platinum. That was the point of my initial article--finding the best replacement source for the Sears Diehard Marine Platinum Battery.