I have a new ES300h with only 2700 miles and it already left me stranded 3 times because it won't start. I had the dealer send out a technician and he jump started the 12 volt battery so it would start. This happened once in a parking lot and twice in my garage. The dealer said he couldn't find anything wrong which made me even more concerned about being stranded in the future. I sometimes don't use the car for a few days but that shouldn't affect the battery. I hade a Lincoln hybrid prior to this car and had left it for 3-4 months and never had a problem starting it.
Any body have an idea? I beginning to lose my faith in the dealer not being able to fix it. I'm also looking at invoking the Florida Lemon Law.

​​​​​​​Thanks

 

The IC engine is started by the 288v Traction Battery, the 12v battery just closes a relay to start the process.
That 12v auxiliary battery (located under the right rear trunk floor) is jumped with a connection under the hood
in the fuse block. Because it is only used to power the lights, wipers, radio and heated seats and not for the
high amp starter motor it somewhat smaller than traditional car batteries. It doesn't take very long for a dome
light type draw to deplete it. Your dealer ought to conduct (pun intended!) a load test and perhaps replace it.

 

Maybe you should call Lexus Customer Relations to report the problem. If your dealer can't find the root of the issue, ask for a Lexus Tech to check out the problem.

 

Thanks for your suggestions .mcomer and MikeP. I appreciate your responses. I spoke to the dealer and they will pick up the car today. I suggested they tow it since I left it with the battery drained rather than charged so they can hopefully check it out with the problem as it is. We'll see what happens.

 

Same problem with my wife's new car this morning. Would not start. Took my car, and came back an hour or two later. It started right up. So no, I do not buy that it is the 12v battery not having enough charge. Unless they can self-charge if they get low. Something is wrong. They need to fix this. I also do not look forward to being stuck somewhere because this thing has an issue,

 

That can be a relay related problem.

 

I know it’s been over a year since you posted this issue but did Lexus ever figure out what the issue. Thanks

 

Yes, it's been fixed. Lexus didn't figure it out. I did. It was what I said the first time it happened. The 12 v battery had a cell problem and wouldn't hold a charge. The frustrating part was I had told them the first time it occurred that the 12 v battery was the problem since one contact was already corroded.. That doesn't happen on a new battery. They went through computer checks and all that high tech testing but didn't look at the obvious. After working on cars as a hobby all my life including restoring three classic cars, I know what I'm doing. Perhaps after I told them I've kept a running report on what's happened and I qualify for submitting a complaint under Florida's Lemon Law, that may have made them to finally take notice.

Sometimes the answer to a problem is the obvious one. It certainly rang true in this case.

 

A friend had a new Infinity QX, and had the same problem. It took several times of jumping the car, and finding nothing wrong when I said it sounds like the battery was bad. They didn't have a new battery to replace it and I told him to make them pull one out of another vehicle sitting on the lot.

Problem solved!