00 Avalon Going through batteries every 2-3 months

[mhansen111]

I've never had a problem with this Avalon. I have owned it for 7 years now and have not modified my use. A battery will turn the car over for 2-3 months but then it will start dying if I don't drive it every day. So long as I drive every day, I can start the car the next morning for 3-4 months before the battery completely dies.

I took it to a mechanic and he said the battery was bad even after I explained how it will start if I drive every day. Said he checked the charging system and it was fine. Battery died in 2 months anyway. Then he said the alternator had to be replaced. Took it to Toyota and they said the charging system/alternator was fine and changed the battery as well as fixed the map light. Now the battery is dead again.

Seems like something isn't turning off and is draining the battery. Toyota checked and they said nothing showed up when they ran the diagnostics. Any ideas? I love this car and would hate to keep buying batteries.

[360glitch]

Is the car stock? Aftermarket stereo system or anything?

[buchaja]

Your battery should be under warranty. If Toyota put in a new one, checked the system and said everything is OK, then have them replace it.

Keep going back until they get it fixed. You paid for the work, right? It's on them now.

[eurobob1978]

I had a battery that had a couple of shorted cells. The car would start and drive, but if I ran the a/c even after a 30 min drive, the car would not start after that. The reason is because a typical battery has 6 cells of around 2.2v each in series. If the battery is reading around 10.4V off, most electronics in a car will not work at 10V which is a real problem when a current hunger device like the starter needs to go to work. Make sure the battery is secured as well, a bouncing battery will short out the plates and it will get worse before it gets better. I also noticed my positive terminal did not fit that snug anymore, double check that maybe?