Here is my problem with Interstate batteries. There are two prices on each battery, a list price and a sell price. If you buy a battery, and it goes bad before the warranty expires, they pro-rate a new one. But they pro-rate at the list price, not the sell price. So if you buy a battery for $100 the list price might be $150. If you have to pay 50% for the new one, you pay 50% of $150 not $100. So you fork out $75 instead of $50. I don't know the exact numbers and I don't know if they still do this so you might want to look into it and read the fine print before you deal with them.