U8pilot

I have a 2003 LS430 with 57000 miles on it. If the car is not driven every 5 to 7 days, the battery goes dead. If anyone has experienced this problem, I would appreciate hearing from you. Thanks

lexman52

Something is drawing a very little power. Do u leave the key close to the car? Or maybe the battery is going.

bmore430

How old is the battery?

Smart Key?

U8pilot

I failed to mention that the battery has been replaced 3 times in the last 5 years. I thought the problem might be the little light that shows that the anti-theft system is armed, but the Toyota dealer says no.

lexman52

Replacing the battery 3 times in 5 years tells u the there is a bigger problem then u think. There is something drawing power 24/7. Or the altinator is bad.

BradTank

Did you pay the Lexus dealer to diagnose? They should have given you an answer

There's clearly a draw somewhere, the "old school" way was to hook a test light between the car battery's negative cable and negative post and pull fuses until the test light goes off, but with newer cars there is sometimes enough of a draw that you have to use a multimeter

Tom57

The "draw" could be the alternator not putting out enough amps to recharge the battery. I'd have the alternator checked first by a reputable technician, before you spend time trying to track down a short somewhere. While your mileage (57K) isn't typical of alternator failure on the LS, you are in a hotter climate than snow belt folks, and heat alone can take its toll on the alternator.

Bocatrip

For what it's worth, you can also pick up a cheap multimeter for $10 at harbor freight and check your voltage output once you start the car and again after it's warm. With the car off, it should be around 12.5+ At startup you should be 14.2-14.5 and once totally warm it can be as low as 13.4-13.6. If you are not within these ranges, that could be your culprit for the premature death of your batteries. Batteries like to stay fully charged or close to it at all times. If your battery is not getting enough replenishing from your Alternator, the chemical degradation of your battery is sped up thus causing it to fail prematurely. Of course you can also have a constant drain when the car is off frojm another source. Start with a fresh fully charged battery to get the best and most accurate results. Good luck.

Lexie's LS

270k miles

Dead battery syndrome for 2 years. Toyota replaced combo controller which drew heavily on battery at operating temp. Problem solved--for several months.

Johnhav430

What's the on/off switch btw? My uncle has an Acura RL which has the same issue, can't be started if it sits 2 days, dealer could not find any problem, nor could the indie. I can imagine it's frustrating....

BryanHall

Are you using the SmartKey? The car sends out a signal looking for the SmartKey on a regular basis. If you don't drive the car very often this will drain the battery. Turn off the SmartKey by clicking the button under the dash on the right side and see if that helps, or you can always trickle charge the car when its in the garage.

Johnhav430

Is that how it works? If so very poor design such that a car can't sit a few days? My LS has sat around 6 days and fired right up...

BryanHall

The previous owner of my LS had a similar battery drain issue that disappeared once he turned off the SmartKey. I don't know how long it should last between starts but between the SmartKey, security and whatever else they have running all the time I can imagine the battery would die eventually. I assume you can leave the SmartKey in the car and it may stop the constant pinging from teh car looking for the key, but thats just a guess.
The manual has a page about disabling SmartKey if the car is going to sit for an extended period of time so they must know its an issue.

XJSFan

Find a Batteries Plus store and go in and have them test your electrical/battery system. They will tell you what is wrong if anything... If you need a battery, they will install it correctly.

Johnhav430

Hmmm....doesn't sound quite right....in its life, my BMW has sat in the garage for 5-6 mos. and starts right up. It has comfort access which is the equivalent....now I throw a tender on it in an attempt to prolong battery life