I have a 2019 UX 250h with 67k miles. I service the car at regular intervals at my local Lexus dealership. Last one was about 3k miles ago.
I've never had any issues with the car starting.

Last week I went to a doctors appointment - car was running just fine. I parked the car in the lot, went in for my appointment and was back in my car in about 30 min. When I went to start the car nothing happened, I tried again and lights started flashing across the dash. I called Lexus to ask what I should do and they told me to not do anything else and to not drive the car even if I got it started, so I called a tow company and had it delivered to Lexus.

The next morning, they looked at my car and told me my 12 volt battery was dead. To make a very long story short, I had the battery replaced, but I asked why I didn't have any warning the battery was going bad and apparently there isn't any type of warning light on this car. This is really a problem.

Does this make sense to any of you with mechanical knowledge? Fortunately it was daytime and somewhere where I could get a tow and an Uber home, but what if this had happened at night in a remote location? I have other cars and have never experienced anything like this.

Opinions?

 

I have the bad news. 250 is the Vorst from Lexus. If your com hires before you buy....The 250 is acting like that. Noting you can do. 250 is experience car. Sorry.

 

That battery behavior is not unusual for being six years old. Some going bad, you can spot as the lights flicker or look dim and starter cranks slower. Others will start and behave normally one second and then strand you at the mall, leading you to suspect something else may have gone wrong. This latter thing has happened twice to me. But I’ve greatly reduced that happening again by putting a volt gauge in a power port. You can run your own load test of sorts. It is not 100% accurate but will significantly help pinpoint a bad battery and/or alternator before it strands you. I also bought a $25 battery tester, a Topdon AB101, that more accurately tests car batteries, AGM included. I test my car batteries at every oil change and before long trips. I record the results and can see as the CCA figures start declining.

Some cars have a check light for the charging system which usually does not detect a dying battery. A volt meter/gauge can help with that

This is one I have:
https://a.co/d/2qDZzom.

 

You should peer into the 5th Gen RX hybrid owners sections and their 12V battery problems in brand new vehicles.

More expensive Lexus dont have a way of warning you directly.

You can either ask for a yearly load test of the charging and battery system to spot early failures
Proaactively replace said battery at an optimized interval
Buy yourself a battery tester off Amazon and test the battery yourself to avoid said circumstances.
Buy yourself Triple AAA or an onboard jump pack.

 

Well thanks for the responses and suggestions. Now that I know there isn't any of low battery warning, then I'll just have to make sure I'm more proactive in the future. I have a new battery, so hopefully I'll be ok with that for a while.

 

I just wanted to let you know that there is a Technical Service Bulletin applicable to this and requires a firmware update.

My UX had similar issue and Lexus replaced the battery once. Then happened again with a new battery after about 4-6 months. I was the one that found the TSB and suggested to the dealer to update it, which they did.

After the update I have not experienced any issues.

I have tried to find the TSB number but have failed. I WILL find it and update this post, but I suggest contacting your dealer.

I think i found it, mine is a 2020, and this bulletin does not mention 2019, but worth looking into:
https://static.nhtsa.gov/odi/tsbs/20...24105-9999.pdf

 

Hi,
During pickup day my 2025 UX300h (eight month old) 12V battery died. They replace right away, but problem exist.

 

It is under the warranty. They have to fix it.