I don't have that issue, mine dies, I just push start it....

Then drive to have new battery installed.

 

Only time rear hatch became an issue for me was when the accuator failed.

 

Well, it does help for the front / back weight balance, and as mentioned, keeps the battery out of the nasty environment (heat & corrosion wise).

I'm also not sure if I'm reading that it CAN be recharged from the terminal post under the hood? Can anyone confirm ?

I'm an engineer by profession, so I tend to try to anticipate what may or may not go wrong with any given design. Can't help it....

My comment about the main battery cable potentially wearing out it's insulation and shorting under vibrations is pure speculation on my part, but I've seen it happen elsewhere and would surely like to know what the HHR designers have done to prevent that. Again, this just stems from the fact that the cable is longer than usual, therefore more "exposed" to this problem.

Yves

 

DreamHHR....

can't tell you to what extent GM consider vibration....but I'm sure they did. To what degree is questionable.

I did a total custom El Camino about 20 years and moved the battery to an insulated box in the rear bed. Ran the cable along the frame and used black HD "zip-ties" to secure it. Never had a problem in about 15 years. The real issue is to assure the cable is stationary and secure just before connecting to the battery.

In any event, you may be a little over attentive