I've had good luck with the Interstate ECONOMY batteries. They are $39.95 each and have a 30 day warranty. I have bought a grand total of 6 of the Economy batteries (2 sets in the Ex, one is a previous vehicle and one currently in the Jetta) and have had no issues with them. The only bad thing about the Economy batteries is they either have to come from an Interstate All Battery Center, or off an Interstate Truck, but I have a shop on the way home. Honestly, if a battery doesn't fail fairly quickly, it should give you a good life. I got 4 years out of the last set in the Excursion, and with all reports I have read, I was EXTREMELY lucky to get 4 years from a set of batteries in a 6.0. The 6.0 is very ******* batteries, and most guys report getting about 3 years from a set before they start to go south. This is even with the more expensive batteries also, like the DieHard Golds, and even the high end (not AGM) Interstates. The one in my Jetta would start it with a failing starter (The battery confirmed it was the starter) without help, the battery that was in there needed a boost to start the car with the same starter. I look at it this way, I can buy 2 or 3 sets of Economy batteries for the price of 1 set with a warranty that will get me 20 bucks of my next $100+ battery...... I will stick with the Interstate Economys.... they have not caused me any issues........