The same thing will happen if your shifter brakes at least on an automatic. When the pin in the shifter brakes loose it will no longer trigger the key release..........

I was just glad I had read about it here before mine decided to do it. Never had to leave the key in the ignition.......

 

Okay, so my key is ‘stuck/kept’ in the ignition, and the battery has ran down to approximately 4 V. After removing the key via the concealed emergency key release, I decided to pull the battery to charge outside of the vehicle. With the battery ran down the rear hatch door will not open as normal.
Is there a manual override for the rear hatch door as well?

 

https://www.chevyhhr.net/forums/how-...-release-8540/

 

Whopper answered your specific question but I do have an alternative........

Open the hood and connect to the under hood remote terminals, PROPERLY. You can either charge this way or boost this way. If you boost, you will have access to the hatch area and then remove the battery for external charging.

AND AGAIN, PLEASE NOTICE MY CAPITALIZED WORD PROPERLY. DO NOT assume you know how to correctly connect the cables if you do not know why I am emphasizing the word PROPERLY. Because you will screw things up. It is different than most vehicles.

 

X2 what Snoopy said!
Use the bolt on the drivers side strut for the Negative (blk) it is marked, and the stud under the red hinged cap on the left side of the underhood fuse block. No need to open the fuse block.

you can either "jump" with another vehicle, or just put a charger on these. I think this is much easier than opening the rear hatch using the emergency release which can be hard to hard to find.

 

The strut studs on my 2009 are marked with Green paint.