My 'stang is about 2 1/2 years old, and for the past few months, the battery has been getting progressively worse. I had the dealer check the battery last November, and they said it was good. When the dealer did an oil change in January, they also said the battery was good.

Well, it was to the point that when the car sat for four or five days the battery was almost dead. (Yes, I turn the Shaker 500 off with the switch.) There was also a differential among the cells when measured with a hydrometer. So I was set for battle today.

The service adviser (SA) tested the battery with a little hand held device.

SA: See, it says battery good, 12.6 volts.
Me: That's with the surface charge. How about we turn the headlights on for two minutes?
SA: Okay.

Reading was then 12.18 volts and said battery needs charge.

Me: And what about the differential among the cells? How about using a hydrometer?
SA: We probably don't even have one around any more.
Me: You want to borrow mine? I have it in the trunk.
SA: No, we use a machine. I'll have a tech test the battery. Do you know where the waiting room is?
Me: Yes. And just give me a new battery.

Ten minutes later.
SA: We're going to replace the battery.
Me: Fine.

Ten minutes later.
SA: The car's ready.
Me: Thank you.

When I drove in, the initial "test" showed the battery was good. The final service order said, "Failed parts test and verified engine cranks over slow. Test - low charge - charge battery failed - replaced battery..."

Overall, getting the new battery under warranty wasn't too bad for me. I was in and out of the dealership in half an hour. I really feel for those people who go to the dealer, are told things are good when they are not, and then get stranded somewhere.

For you guys who don't know much about cars yet--get yourself a GOOD book about basic car care. I like the Popular Mechanics Complete Car Care Manual. Auto Repair for Dummies is awful--it does contain some useful material, but there is too much in the book that is just plain wrong.

Sometimes knowledge can be better than a mod.

 

You lucked out with your dealer. Good job.

Batteries are considered terminal hardware like brakes and tires and typically not covered under warranty. I'd stick with that dealer.

 

I recently had to replace my battery (Arizona EATS batteries) and had to call around to 6 different places before I found the right battery. 150 bucks for the battery. Common car, rare battery.

 

My battery died after almost exactly 2 years. Drove down to the dealership, parked in the wrong spot and when I went back to the car 2 minutes later the battery was dead. Still they did their tests and after they found it bad, they gave me a new one, no problem. My sister had the same problem in her GTCS after 2 years.

 

My battery in my 08 F150 didn't even last 4 months, it had to be replaced, unfortunately after it leaked acid all over the engine compartment and they had to repaint everything under the hood, my service manager said it was a rare occurance, oh well, I guess things happen. I have a 6 cell Optima gel battery in my GT, the previous owner said he didn't want any starting problems since the car sat for weeks at a time without being started, so hopefully I should be good. My question is has anyone else ever seen a yellow top Optima battery, I only seen red ones?