On three occasions in the past three months battery has required jump when parked overnight or all day. Do not believe it to be user error since driver 1 had not been in car for two weeks prior to third occurrence. Dealer ran diagnostic tests on all three occasions but found nothing wrong. Dealer did replace battery. Want to keep the car...but. Any suggestions?

08 LS 460

 

Dead batteries have three possible causes.

1. Defective battery

2. Defective charging system.

3. Abnormal parasitic load. (Two subcategories: A - defects and B-operation errors)

The easiest place to start is to replace the battery.

The fact that you "had not been in the car for two weeks" has no relevance. A fully charged good battery with no abnormal parasitic load would last many months and a defective battery could have been dead when you turned the ignition off.

 

The first thing I would do is have a load test performed on the battery. This will tell you if the battery is good. Next have a multimeter put on the alternator to see if its putting out the right voltage.

If both those tests check out OK, then you need to start searching for something drawing current. The first suspect is the trunk light.

 

He said the dealer replaced the battery. My car sits in the garage and I don't use it a lot. I keep a battery tender hooked up to my car when it's garaged. I only have 14,000 miles on mine in 5 years of use. I just replaced my factory battery yesterday at the dealer. I also got rid of the crappy Dunlop tires my car came with and replaced them with Michelin's. I had the dealer load test my battery and it failed.

 

I found a way to avoid changing the battery on the 2007 LS (October 2006) I had.

 

I know - you bought a new car?

 

Yup. Very, very minimal wind noise.

 

Is there a way to disable the factory installed anti theft alarm system? I too only use my car on occasions and park in a indoor attendant garage.

Happy and Safe Holiday season wishes.

TIA