Leaving key in car -> 12 volt battery drain?

[Dave T]

Normally I take the key out of the car when I leave it in the garage. I've always been afraid that leaving it in could lead to battery drain. My car has been at the dealer's the last few days, and they dropped it off at my house this morning, leaving the key in the car. I decided to keep it in there and see what happened. I made sure the car was "off". When I drove the car a few hours later, I saw a message on the display, something like "PCM can only be used with sufficient battery charge". The message went away, and the car seemed fine. But am I in imminent danger of the dreaded 12 volt battery issue? Is there some way to see the current state of charge of the 12 volt battery? I've never seen that message before, so am wondering if it was caused by leaving the key in the car. The main battery bank is charged to 85%.

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[RRVV17]

Normally I take the key out of the car when I leave it in the garage. I've always been afraid that leaving it in could lead to battery drain. My car has been at the dealer's the last few days, and they dropped it off at my house this morning, leaving the key in the car. I decided to keep it in there and see what happened. I made sure the car was "off". When I drove the car a few hours later, I saw a message on the display, something like "PCM can only be used with sufficient battery charge". The message went away, and the car seemed fine. But am I in imminent danger of the dreaded 12 volt battery issue? Is there some way to see the current state of charge of the 12 volt battery? I've never seen that message before, so am wondering if it was caused by leaving the key in the car. The main battery bank is charged to 85%.

If you use the information view on the right side of the curved screen, it shows 12v battery meter. Mine always shows 13.4. Sometimes when I get in the car, even after a couple days, it may drop to 13.2 worst case but as soon as the car kicks on and the main battery starts charging it immediately goes back up. Never as low as some of the issues experienced on the other threads regarding the drain.

 

[Doc B]

If you use the information view on the right side of the curved screen, it shows 12v battery meter. Mine always shows 13.4. Sometimes when I get in the car, even after a couple days, it may drop to 13.2 worst case but as soon as the car kicks on and the main battery starts charging it immediately goes back up. Never as low as some of the issues experienced on the other threads regarding the drain.

I had a spell of a week when I used to keep getting the "PCM can only be used with sufficient battery charge" message, and it would just disappear after switching the car on and off. I don't think it's related to the 12V battery issue (I hope), and I think it's just a PCM bug. I hadn't left the keys in the car when it happened.

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