twice i left the dome lite on overnite and it did not kill the battery

 

We left ours parked at the airport for a week or more at least three times. Started right up each time.

 

Yes, it does. That was one of reasons I wondered if something else was up. I will just have her keep watching it and check the positive terminal under the hood as suggested.

 

Yesterday, I left my cell phone charging in the car for 30 minutes. JumpStart!

 

Unfortunately the batteries in HHR's are small and fairly low capacity. Having said that, it should be able to sit unused for at least three weeks or more, as long as the battery was close to or fully charged prior to parking the car. I believe somewhere in the manual it says 28 days is about the max it will go and still start.

 

a full charge is hard to achieve if the terminals both positive and negative are dirty, rusty or loose!!

 

I agree. Mine are all clean and tight. So far it is starting fine after open hatch incident, but it has been started everyday.

 

My 06 has the original battery. It sometimes sits for a month or more without being run and still starts.