People can get pretty wrapped up into brand names and original equipment brands. My first job out of college was a somewhat short stint in a factory making air filters. Very short as it wasn’t my cup of tea, no offense to anyone who makes their career doing so.
We slapped various name brand stickers on the same product, some of which I sell today. My primary job is no longer sales in the automotive aftermarket, but I still keep up on some. When it was, there were only three manufacturers of automotive batteries in the United States. I sell name brand manufacturer’s products, they are not relabeled as some suppliers are.
Unfortunately, as a consumer, there’s not a lot of information available to you as to what quality you are purchasing, other than a price difference. I can tell you there are some differences in “cheap” batteries. In a conventional battery, you can tell by weight. They lighten them up by using less lead in the plates, which reduces manufacturing costs. It also causes batteries to fail more easily and the lifespan of economy batteries is not as long.
Interstate has gone through some changes, I know they don’t make all of their own batteries any longer. Not sure if they make any. In AGM batteries, you are really buying the backing behind the battery, and really, that’s in any battery other than what we’re starting to see come out of China. Lithium is a different cat, there are some differences in quality but yet to see if the life holds out on what the manufacturers are saying for them.
You don’t generally see a lot of failures in name brand batteries, or those that have a name brand behind them. Many we see in warranty are neglect by the owner, but we still stand behind them. I’ve had customers tell me flat out they have clearly neglected their battery, let them freeze without charging, not strapped them down, things like that, and we still take them back if they asked.
If you ask yourself, how many Chevy battery factories do you see out there, or Ford battery factories? None. Why is that? Because they don’t exist. I’d wager a bet that is totally the same for Mercedes-Benz battery factories.
I wouldn’t sweat the battery brand. The change is probably due to the major shortages that are happening because of the COVID shutdowns. We had a hard time getting AGM house batteries this year, it took months for them to come in. Interstate has always stood behind their batteries, and they are a good product. Might be the same battery Mercedes purchased and slapped their OE sticker on.