First question is why a new battery in 3 years they should last at least 5 years and many go 6 and 7.
For a battery to only last 3 years would rase question on how it was cared for when bike was not ridden and if connection are good.
I use Deka batteries in everything. Deka is from what I have heard is the oem supplier to Harley. I do not like giving money to Harley Davidson.
Kemo
From what I have researched, Deka is the house brand that is made by East Penn Mfg. Co. who are the OEM suppliers for HD. The Deka has extra heavy duty terminals with top and side bolts. When it's battery time, I will be buying a Deka.