I have my buddy's house and car keys while he's away for a few months. His 2023 Mercedes GLC 300 sent a notification to his phone that his 12V battery was low. I went over and drove it around to charge it up. So Lexus drivers rejoice that others have this problem too.

I have yet to get the notification on my NX450h+ but it usually gets driven often enough that it's not a problem. At least I don't think it's a problem because I don't monitor by 12V battery.

Question for the people in this thread, with the ability and care to monitor their 12V battery, does using the remote start feature charge the battery? I believe it must because the remote start can turn on the HVAC for heating/cooling and that requires the high voltage battery. There shouldn't be any reason for the DC/DC converter not to also turn on in this case.

 

Unfortunately, the NX does not push a notification when the 12V is low. So you won't know. I hope you will never see this 12V problem, but if your vehicles charge the 12V like many of ours, it will one day drop down to a point where you will have problems. The remote start feature does charge the 12V battery - but it stops at 20 mins, and you can't remote start it again until you physically start the vehicle again. Plus, the 20 mins charge the battery 10-15% in the 20 mins timeframe (typically it charge at 13.x volts). I remote start my vehicle every morning before I leave the gym so that it gets some charge while I drive home and then I leave the car running for another 15 mins before shutting it down to maintain the 12V battery.

There is a video on post #12 that can give you some insights on the charging pattern.