timoat

Hi guys, Im a happy Rx450 h owner, Ive had it for 2 years now. I dont drive with it very often, a few times a week for a couple of hours all in all.
Recently, 3 times in the past month, Ive been unable to start the car. (cold start) The alarm goes off when I open the door, and then all systems are unresponding. I had to get a tow truck. They used a battery jump kit, and it started right up, I then drove to the dealers 20 min away. They did a battery check, voltage was fine, so I drove home. It then happend again, and again I called tow truck, same story, it worked on the jump. Dealer can find no wrong, no error codes.

It just happened today again, and this time I had bought my own jump kit, started fine with it. Should I really need to have a jump kit on a 60.000 dollar car thats 2 years old?

Things ive tried:
changed the key fob battery,
checked that the car batteri is fine.
no usb charging tech is hooked up,

Could I be shutting the car down in a wrong way, accidentally? Am I in accessories mode without even knowing it? I found that there is an emergency start procedure, I will try that the newx tt ime it happens.

http://www.lexomans.com/manguide-754.html

Does anyone have any experience with this issue? It would be much appreciated, any help or any ideas!

tus

Just testing battery voltage really tells you next to nothing.

Take it somewhere else and have them load test the battery.

salimshah

Is the 12v battery 2 yr in age?

Depending on use and conditions it can be 3-7yrs (typically) of life.

Batteries are like work horses ... if you dont use them their life is shortened and if you over use them their life is shortened.

From the symptoms, it seems you need to replace the 12v battery (boost works) and if the battery age is 2 yrs, charging system may need some checking [can be unique for hybrid as there is no alternator]. .. maybe dealer already did that.

'tus' correctly pointed out that voltage is not a complete test for battery.
Salim

kezgao

It also sounds like you may not be driving enough? It takes a good amount of charge to crank the engine during ignition. As you drive around that power is recharged back into the battery. If don't use the car all that much it'll drain slowly. There are fans and what not that runs every few hours even when the engine's off. If you're only making shortly and quick trips your battery might struggle to maintain it's charge. Especially in cold weather when battery performance will be negatively impacted. A 20 min drive to the dealer might sufficiently charge your battery so the dealer doesn't detect any issues.
I would try replacing the battery and see if it helps. If you live in a cold climate where you see subzero temperature, maybe consider a battery with 700+ CCA rating.

tus

The OP has a 450h. The traction battery is used to start the motor, not the 12v.

However, if the 12v is dead there will be no power to the electronics and other things that the 450h shares with the 350, which would explain his problem.

lexusrus

Is this RX still under warranty?

If yes, I would just let Lexus dealership figure it out.

Gampa

Had a similar problem with Wife driving 450H... jump starting the hybrid meant connecting special points.. after the third drain, I figured out the wife was turning the light switch from "auto" to far left "dsl's" . It drained the battery.
Battery was dead by then and it was over 4 years. So I replaced the battery with Yellow Top Glass Matt from Sams and told her to leave it on "Auto" settings... never had problem again.

timoat

Ok guys, happened today again, they checked the battery and found nothing wrong with it. My dads jump kit didnt work this time, so they used the tow trucks. The dealer changed the battery, now we will see what happens.

SusanBurn

I had similar problem, it was intermittent and got worse with time. They said I needed a new cranking battery ($450)! Sounds like it does! I'll give it a try. Not understanding why it eventually starts if it's the battery. Does explain why it didn't fail since above writer indicates the battery had to be "load tested." It was in last week for the same problem and I was told they couldn't find anything wrong with it. I'm hoping the dealer is right, because if it reoccurs with a new battery, I will NOT be a happy camper.

MellonC00

Mods please move this thread to the hybrid forum

salimshah

Are we talking about 450H?

Salim

SusanBurn

Yes. A 2010 Lexus RX 450H.

salimshah

Thank you for the update. What threw me off was "cranking battery". RX350 uses the 12v battery to crank the engine. Some one misinformed you as the traction electric [high voltage] motor is used to crank the engine of 450H.


Moving the thread to 450H Forum.

Salim