Why is my 12V battery draining when I don't drive?
I've noticed my 12V battery voltage is dropping pretty noticeably when the car sits idle. I'm not sure if this is normal or if I should be concerned. Has anyone else seen this? I'd like to figure out what's going on before it becomes a bigger problem.
12.2 after a couple of days is getting low for an AGM - that's somewhere around half charge. Still haven't said the make though. If it has an app that can remote start or check charge status, try turning that off for a few days as a test and see if the voltage stays put.
Ioniq 5 here and mine was doing the same thing. Sat around 12.2 to 12.3 most mornings and then one day it just wouldn't wake up. I ended up turning off a bunch of the comfort features and it's been better since but I still don't fully trust it
fwiw those cheap plug-in readers in the 12V socket aren't super accurate, and on some cars the socket only stays live for a bit after you shut off, so you might be reading it with stuff still awake. If you want to know for real, get a bluetooth monitor that clamps on the battery terminals and leave it on for a week. Then you get the graph and can see if it's dropping steadily or in chunks overnight.
