gamma742

We are talking about the HV Charger that come with the 450h+

twitte

No, my problem/issue is with the 12 volt battery going dead. There are no issues with the traction battery or my Level 2 charger that I have in my garage to charge the car. That all works great.

wrinkle

The 12 V battery goes dead if you leave the Level 1/2 charger plugged in to the car, beyond the time it takes to charge the traction battery (sounds like that's what you did ?). That's what is being said above by the folks.

twitte

I don't believe anyone above is talking about the 12 volt battery going dead from having the Level 2 charger plugged into the Lexus traction battery. The first time my 12 volt battery went dead my car wasn't plugged into the Level 2 charger for the traction battery. I think most people above are talking about the 12 volt charger being left on the 12 volt battery too long and the 12 volt battery is going dead.

NX450Guy

I think I did highlight the mysterious link between the 12 volt going dead and the charger. What happens is, charging the car (traction battery) can accidentally significantly drain the 12 battery if the charger is left in after the traction battery is charged up. Best practice is to unplug the charging cable when you’re done to stop the parasitic 12 volt battery drain leaving it in can cause. Even if you take it out and the car doors open, the 12 volt may be so drained that leaving a door open for just a few minutes could finish it off.

wrinkle

You misunderstood the posters just above - they were exactly telling you of the 12 V battery dying if you leave the level1/2 charger plugged in beyond 100 % charge. That’s not the only way to kill the 12 V, but just one of the ways. One of lsft’s videos measures/documents this phenomenon of 12 V discharge

twitte

My dealer has been testing the car after my 2nd dead battery issue. They had the car for over a week and replaced the battery. They claim it is working fine now. I get to pick it up tomorrow. Should be interesting to see if they are right.

Update 5/2/24: Dealer paperwork shows during inspection my concern was duplicated. Diagnostics check found code P05880 One. Power Draw Test Good, Charging System Test Good. Battery Test Bad (tested with Midtronics DCA 8000 Diagnostic Charging System). Battery internal failure (fails load test). Car was tested several days after battery replacement (replaced with Interstate 00544-MFH50) and no problems observed.

PS - Regarding the discussion about possible draw issues on the 12v battery with Level 2 charger left plugged into car after charging, I have been plugging my Level 2 charger into my car almost every night from about 6 pm to 7 am for the last 2 years without having the dead battery problem (until recently). I plug in and leave it because my car is programmed to charge at 12:05 am when my electric rate is the lowest. I'm not about to get up in the middle of the night and unplug my Level 2 charger after the traction battery is charged. If there was an issue with a draw from the Level 2 charger you would think that this would have happened a long time ago.

gamma742

I do the same only set me departure time in the charge schedule for 6:00 am when the electric rates go up.. My car starts charging at around midnight until 6 am. maybe the 12v are only good for 2 years?? Did you have to pay for the new 12v or was it covered under warranty?

twitte

Lexus covered the new battery. I didn't pay for anything.