Originally Posted By: Vikas
All warranties are like that. No warranty gets "reset" once manufacture replaces the faulty part. Otherwise, somebody would get it free "forever".
I can't think of any other warranty like this, actually. If you buy an alternator with a lifetime warranty, and it conks out, you bring it back and your replacement alternator carries that same lifetime warranty.
Using a proration example, if you buy 80,000 mile tires that last 40,000 miles, and you warranty them back to the manufacturer for the prorated amount, and buy new tires, your new tires don't have a voided treadlife warranty -- they have a brand new warranty.
A proration is supposed to allow the customer to "sell back" to the manufacturer the remaining life that SHOULD have been left in that product, as indicated by the duration of the warranty (miles, years, etc). Using that concept, I believe Walmart SHOULD have given me a prorate back from my old battery that didn't last the advertised life, I would buy a new battery with that amount off, and my new battery SHOULD have a brand new warranty on it.
This is how battery warranties used to work. It's how most warranties still work.