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Need help. P100D with dead batteries.

Howdy. Someone traded in a P100D at my friend's shop. It was out in the cold for a few days and now it's completely dead.

I offered to let him borrow my mobile charger from my Model 3. But how can he get the charging port open if the car is completely dead?

Does the 12v need to be charged up first somehow? I saw how on older models you pop the nose cone off, but this doesn't have a nose cone.

What's next?

Yes, start by restoring 12V. Here’s how to get to the jump terminals. If you don’t know how to open the frunk, search for that video, too.


I found this video showing how to pop the frunk:

This brings me to one more question... I saw a video where someone had a stuck charging door on their Model 3 (and they couldn't get into the trunk to pull the release). They basically pried the door open to charge it. Is this an option, too, on the Model S? In other words, would prying it open and using the mobile charger charge both the LI batteries AND the 12v battery? Or would the 12v still need to be charged manually? (and how long do you charge the 12v for with a charging box?)

BTW, in the video I saw where he pried the charging door open, it seemed to fix it and it was opening correctly after that, lol.
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I have never heard of anyone prying open the charging door on the S. It has a plastic latch that seems easily broken. And it’s pricey. Finally, I am not sure it would even try to charge until the computer (which runs on 12V) was booted, so you have a chicken and egg problem there

about how long - really just long enough to boot the MCU, unlock the doors and start a charging session. Once it’s booted, and charging started, the main pack will finish charging the 12V. Remember, there is no starter motor or other big draw like starting an ICE car.

if the 12V battery was 100% discharged, it might need to be replaced.
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AIUI, there is a failure mode where the 12V battery can die completely, without the car figuring out it needs to charge it (i.e., the failure is in the 12V battery itself). If that's the case, you could have 100% main battery charge and still see the "completely dead" car symptoms you're looking at.

It certainly sounds like the 12V battery is completely dead; unknown whether the main battery has any charge on it.

Either way, the first step is to gain access to the 12V battery and put enough charge on it to "wake it up." Hopefully it will take that, at which point you can assess the main battery. If it appears that the main battery is doing fine; or if the 12V won't take any charge at all; then the next step is to replace the 12V battery. I'm NOT an expert on this, but a faulty 12V battery seems the most likely culprit here, particularly if the car was driven normally to the lot a few days before this issue.

PS: If 'twere me, once you've gotten into the car, I'd open at least one door, plus leave both the trunk & frunk open until such time as the issue is fully resolved.... :D