I thought it was because companies meet specs, go through the required testing, submit the results with the other required paperwork, and get approval. Other parts may be equivalent quality, but without the appropriate blessing, aren't authorized. Not a bad thing, for aircraft.

Fortunately, parts for our Harleys don't need to be approved, TSO'd, or covered by a type certificate.

 

The Interstate batteries with 500CCA is made by Yuasa for Interstate. Same batteries.

 

How do you know that?

 

It seems there is a pretty common misconception out there that all parts (batteries in this case) are identical that come out of the same manufacturing plant regardless of branding. This couldn’t be further from the truth. Every variation has unique specs to be met. Unfortunately in my experience some accounting person will have a lot of influence on these specs when it comes down to manufacturing cost and competitive pricing. A lot of “common parts” ( filters, hardware, batteries, etc. come out of the same facility under various brands but I assure they are not all identical every time.

 

I had the 500CCA Yuasa in my ‘03, for a year, then I sold the bike. Loved it. If my new bike needs a battery, I’m going with that.

 

"Interstate Batteries, also known as Interstate Battery System of America, is a privately held battery and marketing distribution company. Interstate is not the manufacturer, just the brand. They are made by Johnson Controls and Exide."


Even if Yuasa made that battery for Interstate, it doesn't mean it's the same as other 500CCA batteries Yuasa makes, to include their own brand 500CCA battery. All battery manufacturers make batteries to a spec, for the various contracts they supply. Yuasa can make a premium quality battery AND a bargain basement battery... It all depends on what the contract calls for.. The specs are supplied by the contractor, not the manufacturer.

Almost always, when a manufacturer is contracted to make a battery, part of that contract includes a clause that they cannot make the same spec battery for other brands.

That is why you see some of the "made by the same company that makes Harley OEM batteries, and they are just like Harley OEM" batteries will have different terminals... that is so the manufacturer doesn't violate their contract with HD. If the battery is significantly cheaper than HD, it could also have other cost saving differences like less virgin lead in the plates, thinner plates, etc, etc, etc...

I doubt that Yuasa would supply another vendor with the exact same battery they market under their own label.

 

As I recall, some of the comments we've seen over the years have been by folks who worked in the battery factory.

 

I’ve never had any complaints about the HD OEM battery but this time I went with the Duracell from Batteries +Bulbs, comes with a 2 year replacement warranty.