A couple of times I've run down the battery in my car when in the ACC or IG-ON modes. This has been while I was programming the bluetooth and NAV units, and also when I installed the iPod/SAT interface. Typically the drain occured withing about 20-30 minutes in the ACC or IG-ON modes. Battery voltage was at about 10v after drain. Charges to 12.4v (engine off), and is 13.4v with engine running.

Vehicle is a 2006 GS300.

Is this a normal depletion time for battery drain in the ACC or IG-ON mode?

should be about 14.4v with the engine running, if its 10v after a drain of just 20 min, I would say you may have a bad cell. How old is the battery?

For a point of reference I have used my GS300 with a fresh battery installed within the last year for over an hour with the acc on and no issues at all. most of the lights in a Lexus will shut themselves off after a certain number of minutes to help prevent a dead battery. If you have the audio system really cranking then.. it is possible to drain it down rather quickly, but 20 min is still too low.

Thank you. I didn't realize that I could check each cell on this battery. Thought it was a "maintenance free" type. Sure enough, all the cells were low on electrolyte. Checking the specific gravity, one cell was at 25%, and two more at 50%. Added a total of about 1/3 gallon of distilled water across all six cells. Battery is on the charger now. I suspect that will take care of this issue.

good to hear, I have made it a habit of checking my battery levels about every 3 months, when I do a good detail on the car and the motor compartment its a good time to check stuff like that and will keep you out of trouble if you consistently check it.

Would have been nice if the previous owner had checked the levels. I've had the car for 2 weeks. I bet the cell caps had never been opened...until yesterday.

It should last longer than that though so to answer your question if this is normal depletion time, no.

It does now appear that one cell is dead. Specific gravity of the electrolyte in that one cell is zero.

I called the local dealer and they tell me that the battery is -not- covered under the 48 month, 48,000 mile warranty, rather it is only warrantied for 36 months. Then I chat, and phone, Lexus, and they state that the battery is covered under warranty. How should I handle this when I go to the dealer (and who should I believe)?

my understanding is that everything except wear items (brake pads, tires rotors and wiper blades) is covered under the initial 4yr/50k miles warranty.
The battery is covered.

When in doubt, have your supplemental owners manual in hand and ask them to show you in writing where it states the battery is not covered. If it is expressly stated it is not covered, then it has to be covered. Now, be careful here. Since you have opened up the caps on a "maintenence free" battery, be prepared, they may try to lupole you by saying the battery was tampered with and therefore the warranty is null and void.

steviej

Thanks to all for their input. Got things resolved today.

Car would not start today. Called roadside assistance for a jump. Drove the car directly to the dealer who put in a Toyota Interstate Group 24 battery (84 month), under warranty, at no charge.

So be it for the gal I spoke with at the dealership yesterday who insisted it was not covered under warranty...

Also put a set of Kumho Ecsta Platinum LX 245/40-18's on the car today. Nice tire. Very quiet (but then many of them are that way when new). Nice handling. Hopefully they'll live up to their reputation.

Thanks again.