Another difference may be that 2011 and newer's have the HD CAN/LAN system on them and if I'm not mistaken it draws a little power full time.

Look here for some good info. http://harleytechtalk.org/htt/index.php?topic=44738.0

 

MY org batt lasted 5yrs almost to the day..
I knew at the end of the 4th summer it was slowing down a little on starts. So at the start of the 5th summer it didn't come as a shock I needed a new one.

I tender the batt all winter also. so 4-5 yrs is normal, some make it 5-6yrs

I prefer not to be stranded on a ride somewhere with a dead one.

and yeah, the lights still light up good, but she just wouldn't turn over after a couple days of not being on the tender.

I got a Battery + battery (AGM) (made by Dekca - same as the HD maker) mostly cause their 2 blocks from home instead of driving a 120 miles to get a HD batt, and it was only $98 with Senior Discount)
Also it has a 1yr vs the HD 6months warranty. Fit perfect but does have universal lugs (Top and side bolt app) on top instead of one like the HD batt.

With any battery just make sure its made to fit Ur bike..




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