Interstate makes their own batteries; they don't buy them from anywhere. Mercedes and BMW batteries are Interstate batteries (Mercedes and BMW don't make batteries); check with your dealer for proof. I have.

As for warranties and longevity, if a battery lasts 5 years, then you've done good. Often, when we run the proration on a battery, the prorated price exceeds the purchase price right at about the 4.5-5 year mark. When that happens, we just sell the battery at it's normal price. Yes, the 7 years warranty is a marketing ploy whose proration will actually cost you more than a new battery.

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- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600