Just got back from 2 week Disney World trips with kids and I was worried that I would have this issue but my car started up right away even after sitting in my garage unused for 16 days.

 

The battery on my 3IS died today just 24 hours after I last drove it. I have just under 6000 miles on it, and I've had the car since December. I jump started it, left it running for half an hour, and was able to start it on its own again.

I'm guessing parasitic drain is the issue (maybe from a sporadic bug in the software?). I don't make a lot of short drives, so I don't think that's the issue; my last drive was 50 miles.

 

Dead battery for me as well. I haven't started the car since Monday and just went to my garage to grab something from the car and the doors wouldn't open. Used the valet key to get in and the car wouldn't start. I'll call Roadside tomorrow since it's late. I changed the interior lights to LEDs so does anyone think this can be the problem. Trying to figure out what it could be and that's the only thing I can think of.

 

Well if you have read the comments on this post, the Led lights you are concern about shouldn't be the caused. It's an error made by Lexus and seems like it's still unknown. Love the car, but the battery issue is no good.

 

Well, I woke up this morning to a dead battery on my 3IS. Only 2500 miles on it.

I have a battery charger on it now to hopefully get it recharged. I will report the issue to the dealer but probably not take it in until I have a recurrence or I hear of a solution or admission of an issue by Lexus.

I went through a similar issue with my previous vehicle (2012 Infiniti M) and I feel like it's Groundhog Day for me.

 

I have an update on the dead battery issue. Got it towed in to the dealership on Sat. Got the call today from the tech and they said it was a bad battery. Left a meter on the new one to see if any electrical components were causing the drain and he said everything is fine. He said it was just a case of a bad battery.

 

Well I honestly doubt it's a bad battery, seems like the dealership just wanted to swap it out and see if this happens again. Just my opinion from reading previous replies on this post that people did swap out batteries and same thing happened to them again. Japanese Lexus is too reliable to make small mistakes such as faulty battery in my opinion, this issue must be an underlying mystery yet to be solve.

 

Left car unstarted for 6 days, started right up.... alarm was not set either, so not sure if alarm is causing some people's issues.

 

Just happened to me. Left it in the garage over the long weekend and wouldn't start this morning. A little over 1000 miles on it. Going to try to take it to dealer today.

 

I purchased the 2014 IS250 back in November last year. I drive it every day. Recently, I went on vacation for 6 days and left nothing on in the car. When I came back the battery was completely dead (drained) and it had to be replaced. My dealer said it was a known issue. Now should I worry if I take vacation again? How many batteries can I expect to go through?

 

I've had the same problem last week, I didn't drive my car for 2 days and the batteries died on me. I took it into the dealership and they told me I must of left the light on but I know I didn't because the last time I drove was when I got home at around 3:00 in the day.

 

That's crazy cause I just came back from a 6 day vacation and mine fired right up. Maybe it's an F-sport issue, I didn't have my alarm set either so that couldn't have been draining it.

 

Lexus Master Technician here,

Lexus knows about the battery drain issues. It is currently under investigation for the IS/GS models. My dealer alone has seen several complaints about it. At first, we tried putting in high CCA rated batteries, but that did not fix it. It seems like every week, we have a Lexus field engineer at our dealer to examine another dead battery. Just yesterday, our diagnostic specialist had 3 different 4th gen IS models in the shop comparing parasitic draw. Hopefully soon there will be a TSB on the issue; until then i'm afraid there is no fix as of right now.

 

Everyone just needs to have a on/off switch on the battery cause.old Porsches had the exact same issue

 

Great to know this is being looked at! Is there anything I can do in the meantime? I have a few vacations planned this summer and no one to start my car while gone. Lexus replaced my first battery. I’m hoping that fixed the issue so far. I don’t have the F-sport model, but the IS 250 fully loaded.