Don, you probably know this already but on the Deka website it states that this model does not meet H-D oem specs. Can't find detailed specs on the H-D oem battery to compare. 
Harley is loathe to ever give full specs for any of their products, for fear of making it too easy for us to find substitutes in the aftermarket. Kind of like how they don't list full specs and industry standard ratings on all their various lubrication products, or industry numbers on bulbs, etc.
Harley rates the stock Touring model batteries at 28Ah, the Deka claims 26Ah and 400 CCA. The CCA rating for the stock battery in my 2005 was 300, but I have no idea if that is still a valid number for current model bikes (Harley lists the same battery part number for all '97 and up Touring). There are a lot of folks on the internet forums who claim to have purchased and used the Deka batteries with no issues, so the 2Ah difference doesn't appear to be significant. The old Amp-hour ratings aren't all that important anyway in applications with full time charging systems. They would be significant if we were talking about a battery for a trolling motor, or maybe if you like to play your stereo a lot while the bike isn't running. CCA is probably the best spec to use for comparisons, just make sure it's the CCA that's measured at 0°F for 30 seconds; some places like to use other standards to make their numbers higher, like CA measured at 25°F, or HCA measured at 80°F. Those standards are no longer used by mainstream battery companies.
One other point of comparison is the warranty. Harley has their usual 90 day service part warranty, while the aftermarket folks like Deka or Odyssey have one to two year warranties. While I don't necessarily buy all the advertising hype from the Odyssey folks (for instance, just because they call it a dry cell doesn't mean anything special, it is an AGM battery just like the Harley battery), if you can get one for the same price as what you'd pay for the Harley battery it would probably be a good choice. PC925LMJ, two year warranty, 28Ah and 380 CCA. I wouldn't pay the $232 regular price, but I've seen them online for around $180 with free shipping. Try not to fall too heavily for the advertising claims, most of which are comparisons to the old style flooded cell batteries, not the current AGM batteries that are standard in modern Harley's.
Jerry
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Topic: Battery of Choice (Read 4809 times)