Lexus dines on batteries

My wife’s 1998 ES300 has taken a liking to batteries. The first time, we were away on vacation. Returned, wouldn’t start. Lexus said it was a bad battery. We replaced the battery, and it was fine. For a time. This has repeatedly occurred, but the Lexus service people can’t find anything wrong. They have put quality batteries in the car, and it starts for a while.

Last week my wife got in the car, ran a bunch of errands, starting and stopping. After the third stop, she returned to the car, turned the key only to hear that “click” but no turn of the engine. AAA guy jumped it, it’s now parked in the garage. My wife refuses to drive it. Help. Otherwise it’s a new car.

Does she keep the blower motor on high all the time? The blower motor if left on all the time can run the battery down, especially if most of the driving is low speed with lots of stops and idling.

@arrjay perhaps the starter is failing. If the starter is getting 12V when you turn the key to start position, and it just clicks, I’d say there’s a good chance the starter is the real problem.

It sounds to me like you have a “parasitic draw” or “parasitic drain”. Here is a good video on how to diagnose it:

A parasitic load test and a proper test of the alternator should reveal the problem…

Guys, if parasitic draw is the real problem, that must be the mother of ALL draws, if it’s killing the battery in the few minutes it took for OP’s wife to go in the store, and come back out.

I have seen parasitic draw kill batteries in several hours, NOT several minutes.

Parasitic draw COULD be a factor if it is depleting the battery so badly overnight, that the alternator doesn’t have the chance to recharge it sufficiently during short trips.

On my ES it was the contacts in the starter solenoid. If they’re original I bet that’s the problem. Very common, your techs should have known this.

AAA guy jumped it, it’s now parked in the garage.

Did you trickle charge it to restore full charge? This happens a lot. It would take hours of driving to fully restore the battery to a full charge. And lead-acid batteries are damaged when consistently left in partial charge state.

If you’re not charging it once it’s discharged to the point it won’t start the car, even a relatively small parasitic drain can eventually kill the battery. If you’re routinely making short trips it will accelerate the process.

You need to find and fix the cause of the battery drain (charging issue, parasitic draw, etc) but in the meantime, when it won’t start you need to fully recharge it before using it. Otherwise, you’re just killing the batteries prematurely…and over stressing your alternator to boot.

If that car is traded in for a new Lexus could I guess just how quickly the problem would be diagnosed and repaired? My first guess is JIT for the next auction.

Auction, no. that car would be grabbed by someone working at the dealership.

Car has new battery. But new battery can be drained in 1 week or more. So if charging system is bad, new battery could already be depleted. Does car start today? I know it’s parked. If it does not start, have battery load tested.

One area to check is the harmonic balancer. The alternator pulley on the balancer has a rubber isolator that can delaminate from the balancer. This then causes the pulley for the alternator to turn slower than the rest of the balancer thereby not turning the alternator fast enough to keep the battery charged.

Take a piece of chaulk and mark a line across both pulley’s on the balancer. Start the engine and rev up a couple times and shut the engine off. Now look on the balancer to see if the two lines are still lined up. If not the pulley for alternator is slipping and harmonic balancer requires replacement.