The mistake people often make is that just because a battery is made by East Penn (or any other manufacturer for that matter), it doesn't mean it's as good as other batteries made by East Penn.

East Penn can make an exceptional battery, and they can make a bargain basement, low-grade battery.... it all depends on what the particular vendor specs for them to make....

Additionally, when they have a large contract with a vendor, there is usually a clause in that contract that the battery East Penn makes for the vendor, cannot be exactly duplicated for anyone else... A vendor with a large contract can, and usually does, make their battery(s) an exclusive...

So I feel pretty confident saying that the Big Crank, et al, batteries that are made by East Penn, are NOT the exact same specifications as the ones made for the MoCo...

The differences can be small and subtle, or substantial...

For example, that is why all of the Harley clone batteries need terminal spacers, because to make the terminals the same as the Harley battery terminals would be in violation of their contract with the MoCo...

We will never know what other differences there are between the actual HD battery and the clones... it could be plate thickness, content of virgin led, and a myriad of other design differences.... most of which could/would affect the power and longevity of the battery.... some of the differences may actually be better than the OEM HD specs... HD has spec's parts (e.g.- OEM Dunlop tires) that weren't the best they could make, only to have a competitor make a similar, but better part (the Dunlop American Elite)..

While I am confident HD probably has a bigger mark-up than the competition, I seriously doubt the entire price difference is profit.... I'm sure there are differences in quality too.....

The age old question is...... Are they a bargain battery as good as the HD battery, or just a cheap, substandard knock off....?

For me, I avoid the HD batteries..... I have had a few OEM batteries last a very long time, and several HD replacement batteries fall far short with their longevity.

I have had very good luck with Yuasa batteries as first my choice and the Duracell grey case as a close second.... I recently needed a new battery for one of my Softail bikes. The proper sized Yuasa wasn't available from the vendors who usually offer good pricing on them, so I went with the Duracell grey case..

 

I just bought a Duracell Ultra from Batteries Plus in my 2008 Streetglide for about $170.


It works great but next time I am going with this bad boy:

 

To me, nothing beats the Yuasa GYZ32HL 500 CCA cant be beat been using these batteries in previous bikes too.

However for whatever reason maybe supply issues a year ago I ended up at battery mart and got a MEGA Crank 425 CCA because of price. (its important not to confuse bullshit CA (cranking amps) with the real industry standard of CCA (COLD CRANKING AMPS) It blows my mind how confused people are on that BS CA (cranking amps) number, IT means nothing at all and is complete BS.

I dont mind paying more for quality but I couldnt at the time, for the first time ever find a good price on the Yuasa so went with the MEGA Crank for like $110 instead of $180 for the Yuasa which in the past I was always able to buy around $140.
The Mega Crank is good, construction not nearly as good as Yuasa but sufficient. Cranks like a beast and not sure how much longer Ill have this bike anyway... I think.