My 2009 LT would not start after driving it 30 miles a few days ago. The starter did not make any sound. I had to call a garage to jump start it. The windows worked fine and the dome lights were bright but there was not enough battery power to start the engine. Once it did start I drove it back 30 miles. The next day it started without a problem but a few hours later it was harder to start.

I put a slow charge on the battery and let it go for 9 hours. Later the charger indicated it was still taking 10 amps. I did check the voltage before charging and it was 12.5 volts. I also checked the voltage with the engine running and it was 14.7. I stopped charging overnight and started it again in the morning with the battery still at 10 amps. It seems to be taking a very long time to charge even after driving it 60 miles.

I am not sure but it seems it might be a parasitic drain causing the problem. Maybe it's something else of course. I noticed that on the DIC the light that indicates low tire pressure is no longer lit. I know that batteries in the tires need to be changed.The light has been on for awhile. Could the light being off now have something to do with the battery losing a charge?

I plan on going through all the fuses to see if any of the circuits show a drain but wonder if the tire pressure light could be the issue.

 

At 12.5 volts, the battery is not discharged, so I would say there's no parasitic drain. You may have a loose or dirty connection. Check the following locations
battery terminal clamps (also ensure they're not cracked)
Lug on the side of the underhood fuse block (under the red cover)
Large lug on the starter
Large lug on the alternator.

Also make sure the current sensor is in place on the negative battery cable.

You should also take the car to your nearest chain auto parts store for a free battery load test and free charging system test.

 

Load test the battery.

 

Some HHRs have a fusible link between the starter and the alternator. Check continuity there.

 

Lisbon... Portugal or Connecticut or ??

Not sure where to get that service if in Portugal.

 

I did have the battery load tested at a local parts store. They said the battery was good but the charge was low. I asked it they could jump start it and they tried but their charger wouldn't start it. Starter made no sound at all when they tried it so I called a garage. When they jumped it the engine started right up.

I have checked the battery terminals. They looked very clean. The battery is only 2 years old. When I installed it I cleaned the terminals and applied dielectric grease. I just cleaned them again to make sure that was not the problem. I didn't see any cracks but I'll check again. I will go through the other tips mentioned and hopefully find the problem. Thanks.

I am in Lisbon, NY

 

Have the ignition related recalls been performed? Link to check in my signature

 

There were no incomplete recalls.

I looked at the large lug near the fuse block under the hood. It is quite rusty; I couldn't turn it so I sprayed it with penetrating oil. If this doesn't break the rust would an impact wrench damage the lug? .

 

I wouldn’t use an impact gun on that stud, but I would tighten the 4 bolts , 7 mm

 

Where did the parts store hook up to when jumping and checking?
I don't know why you are still fretting about the battery; the parts store answered the question. It is the charging.