I have a 2012 rv 450 and I just replaced the battery in the trunk. I went to McDonald’s and had to wait in the drive up and my car shut off and I couldn’t start it fo awhile,I waited a few minutes and then it started again,the car only has 85000 miles

 

For 450H, i would highly recommend that folks use ... "I did not get 'Ready'" instead of unable to start. Also a description of what is observed in the instrument panel is necessary. [lights up with warning message, or lights up but would not show "Ready']

It can be a "one of", which should be ignored or there can be an issue with the new battery or even with the charging system or actual drain. The later cases can be the reason of the battery failure that you replaced.

if it was simply age of the old battery, then the new battery can be bad too. The sellers are supposed to charge the new battery before they sell them. Good bit of work for those stores is to keep the batteries charged up and they can not leave them charging overnight.

RX [all Lexus] are very sensitive to reverse polarity damage. The batteries come in 'normal' and 'reversed' posts. Lexus also uses wrong color code on leads [I have seen black clamp covers on +, and red covers on -]. You really have to pay attention.

Finally, your 450 [and other RX as well] loose some settings and information when the 12v is disconnected and the vehicle has to re-learn.

Salim
[ps: I have learnt that I have to keep my foot on the brake a bit longer after punching the 'start' button, and if I don't, the instrument panel does not show 'Ready']

 

I was in the line at McDonald’s and was waiting around 5 minutes and my car just died and wouldn’t start. I waited a few minutes and then it started.. I took it to the dealer and they checked it out but couldn’t find anything. Now my wife is afraid to drive it.anyone have this happen. I just installed a new 12 volt battery in trunk last month

 

For 450H, i would highly recommend that folks use ... "I did not get 'Ready'" instead of unable to start. Also a description of what is observed in the instrument panel is necessary. [lights up with warning message, or lights up but would not show "Ready']

Salim

 

My car dies every time I come to a stop. In Burger King it dies and might not restart as creeping forward is battery only, not needing the engine. So mine doesn't restart either.
Your post is rather unclear as just what is meant by it wouldn't restart, as these cars don't start in the first place but simply go into a running mode called 'Ready'.
Your car went dead and would not come on 'ready'?

What could be wrong is your battery clamp isn't tight. ( or is corroded). You changed it and this is an indicator of what could be wrong. Your car "died", clamp is no longer conducting. Car "restarts", clamp is conducting. Its an easy enough thing to check for.
For some reason when we fix an item we tend to ignore that item as a culprit, instead it usually is the problem since before we 'fixed' it we didn't have the problem. And rarely -our fix is defective and didn't fix the problem.

 

Took it into Lexus and they couldn’t find anything wrong with it,they let it idle and said they cleared out some codes that showed dead battery from before I changed it. The car definetly runs better