FYI - Not sure if this will help but very interesting way to check the amps coming out.

 

Adding my story to this. My ~1 year old 2024 Lexus RX 350h (Canada) completely died today. I didn't use it for a couple of days and it's cold here so I started it this morning to charge up the battery and I even looked at the battery screen and saw the hybrid battery was near full. Then in the evening when I pressed START and it turned on briefly and then it shut down and the headlights started flickering like crazy. I had to get out manually and the car was completely dead. This is the second time it has happened to me.

Lexus is really ruining their reputation for reliability with these junky hybrids. I wouldn't recommend anyone buy the RX 350h until these issues are resolved.

 

Sorry to hear that. You can do some diagnosis to see why the battery drained. First of all, hybrid battery being full does not ,Ean your 12V battery is full. 12V controls the starting of the car. Do you drive short distance mostly which did not allow your 12 C to fully re-charged. Did you leave an interior light on for a couple of days because you left a door ajar? Could temperature definitely reduces cranking power.

 

I have documented in this thread my several battery issues. I am more aware of what causes and I have jump packs. But I have a new question/issue.

This weekend I went to see my grand daughter. We have a car seat that stays in our RX350h and a tablet we use for her entertainment on longer drives. Pre Lexus RX350h, I would have no issue leaving the charging cable hooked up to the tablet and the other end in the USB-C on the back of the console or the cigarette lighter charger in the rear hatch. Now that all these battery issues have emerged, is it safe for me to leave the cables hooked up when not driving? Getting a little paranoid, I know, but I am worried about somehow having her locked in the car if the battery problem reared its ugly head. Thanks for any pointers here.

 

Rest assured it is fine. I have a car cam plugged into the USB port. When I start the car, it is powered. When I turn off the car, it powers off.

 

Thank you.

 

A few members of the forum were discussing writing to Consumer Reports, in order to get Lexus to fix the problem. Well, today Consumer Reports killed the 12 V battery themselves, while reviewing the TX 500H. Its at the 5 min 12 sec into the video/review

 

Good that they got called out for the battery fail, prevalent in the brand it seems. Oh, and the slow shifter, really drives me mad, it really is imposible to shift fast, I always get the message to brake first…

 

Two nights ago, I started to back out of my garage and when I put in reverse, the Park button light came on and the work PARK started flashing on the dash. Then the headlights started flashing in an irregular pattern and the door locks started locking and unlocking one door after the other. None of the buttons would respond, including the Start/Stop. I had to use the manual lever to exit the vehicle, and the flashing and door locks continued. I was unable to stop the erratic event. Finally, after some time, maybe 15 minutes, it stopped
I called Lexus, and they asked me to have Roadside bring it to them. The next day, Roadside came and with a jumper battery, the vehicle started, and I drove it to the Dealer. Everything seemed to be normal.
They checked the vehicle thoroughly, including the battery and couldn't find anything wrong. Vehicle is performing normally now.
My best guess is that somehow, I confused the software, and it malfunctioned. We all know that when our PC acts strange, we reboot. I suspect when the battery drained from the erratic event, it was the same as a reboot and everything now works as designed.
Just wondered if anyone else had a similar experience.

 

Yeah, similar experience but it was a few seconds after I started the car. Everything was unresponsive until I jumped the car with a battery pack.

I think it's scary to have such an unreliable vehicle at this point.

 

Haven't had an issue since I got the faraday pouch over 6 months ago, though the battery died earlier today after not being driven for over 2 weeks.

I got one of the portable jump starter but the cable is too short to reach the recommended negative jump point, would it be ok to use where this bolt is?

 

No! Too close to the ECU! Look at post #1024 for a good spot.

Or get a (or similar) that has longer cables and can connect to the officially approved spots.

I have the Schumacher SL1648 and can say from personal experience that it works for jumping the 2023 RX350h.

 

I sent in a complaint/response to their review the the RX (Consumer Reports) with regard to the 12 volt battery.

 

Been trying to do the same thing - but can't find anything on the CR website.
How did you submit feedback?

I would like to submit our experience with the NX450H+.

Everyone here with battery issue(s) should be submitting feedback.

Think someone mentioned it earlier, I also believe the NHTSA should recognize the problems.
Being stranded or STUCK in your car can be dangerous.

 

I believe NHTSA's responsibility, scope and jurisdiction is only limited to safety issues when a car is in a moving/mobile state. So for example, the RX500H's transmission issue-caused violent jerking when coming to a stop would come under NHTSA, but the a dead battery/car when starting an obviously already parked car wouldn't "qualify" as a safety issue.

(Not that I personally care any more, since I've taken care of the entire problem myself completely, but above is my understanding based on my research. Please feel free to cite data/rules/laws that state otherwise)