Battery Life

I have a 2004 Toyota Avalon and it’s on its third battery. Can you tell what would be causing this?

How many miles are on the odometer?
What are your driving habits? Is is purely local driving, with a lot of shutting down the engine and restarting it?
When was the last time that the serpentine belt was checked for correct tension?

Something to consider is a test of the charging system.

Adding to VDCdriver’s list, how many times have you let the battery go dead or near dead?

Another thought: If you’re putting a 3rd battery in a 2004 car, it could have been built in mid 2003. That means you had two batteries in a 6 year period. One of them could have had a ‘normal’ life and only the other one was simply defective. We need more information.

If you can provide any context and background information on when the first two batteries died, that could help us give you feedback.

The first battery was replaced in November 2006 and the second battery was replaced August 2009.

Thank you for that piece of information. Any answers to the other questions? The more you can provide, the less we’ll have to simply speculate.

I have 160,000 miles on the car and most of the driving is commuting 120 miles a day to work. About 50% of my commute is in bumper to bumper traffic. I will have to check with my mechanic to see if he’s checked the serpentine belt. I know he has checked the electrical system and didn’t see any abnormalities. Each time I’ve had to replace the battery there has been no warning, the battery just dies and the car won’t start.

"…most of the driving is commuting 120 miles a day to work. About 50% of my commute is in bumper to bumper traffic."
The alternator, even if 100% good, can’t be carrying the electrical load, and charging the battery in creep and crawl traffic. In that traffic, the engine is, mostly, at idle rpm. At idle, the alternator is only putting out about half its rated amperage.
All of the electrical things turned on: headlights, radio/stereo, wipers, A/C, etc., exceed the alternator’s output. The shortfall comes from the battery’s charge. The remainder of the drive doesn’t fully replenish the battery’s charge. So, day by day, the battery runs less than fully charged, which shortens its life.
You can turn off, or to a lower setting, the electrical stuff. You can raise the engine rpm, when sitting in traffic, which increases the alternator’s output. You can monitor the charge gauge, if your vehicle has one, for discharge periods, and make adjustments to electrical usage, when charge goes low (negative).

My batteries seem to last about 3 to 4 years. Your experience isn’t out of line with mine. BTW, my experience is with a 1998 Regal, 2003 Silhouette, and 2005 Accord. All different cars, but with similar experience.

I am going to guess the charging system is having a problem. Did you have the charging system checked when you had the battery replaced. If the charging system is weak that could explain both the original failure and the second battery problem.

BTW I don’t totally agree with the comment about idling in traffic. While it is more demanding on the charging system, it should not cause a problem with a charging system that is functioning properly. It might cause a marginal charging system over the edge however.

Heat is the battery killer. Stop and go traffic is going to allow heat to buildup under the hood, so 3 to 4 years doesn’t seem too out of line.