Good morning all, long time lurker, first time poster here.

So I'm having some issues with my 2007 Chevy HHR LT. Back in March the car's battery light suddenly came on. The voltage on the battery read well below the spec, like at 11.2 then 9 the eventually 6. So I decided to replace the alternator, that was a fun job! Before starting the car I decided to get a new battery as I assumed that the old one was dead dead and I didn't want to damage the alternator by trying to jump it. The battery that was in the car was actually an AGM from my partner's dad's SUV. it was rocking at least 850 CCAs. I replaced it with an Everstart that matched the stock HHR. The car turned over and it ran like it always did. The only issue was the radio didn't turn on/light up and there were no chimes like say when you used a turn signal. I tried the battery lobotomy to no avail. I swapped a fuse by the kick panel but still no results. But I figured it's just the radio and the chimes who really cares as long as the car is working.

So the car worked great for a month until my partner tried to use it and it wouldn't turn over. I had to use the key release under the steering column to get the key back. I replaced the terminals at the end of the wires as I noticed they were busted. I tried to jump the car but that didn't work. It would just give a few clicks. I then decided to exchange the battery, the folks at Walmart said it was dead dead and gave me a new one. I popped her in and boom it turned over and worked like a charm. It was seeing very regular use with no issues whatsoever. I purchased a charge system tester and everything came back great.

Now jump forward to yesterday and after a 45 mile journey and a few smaller journeys (less than 2 miles) the battery light came back on and the AC seemed weak. My partner turned the car off and tried to start it and it wouldn't turn over. So I drove out to my partner with my tester and a jump pack. When I arrived it magically began working. But I ran my tests anyway the battery was showing that it needed recharged and had about 450 CCAs. The charge system was pushing 8volts without load and 6.5 under load. Not good. Although I concede that I may have messed up that test due to trying to do it by myself. I rechecked the battery and it the tester said it needed replaced and was showing 150 CCAs. I turned the car over one last time and it ran for 30 seconds before dying out.

So now the car is 45 miles away. I'm thinking I'm going to see about exchanging the battery one more time, popping the new one in and I think that should get it at least home. Before I do that though I am going to recheck the alternator connection. When it gets back, I know it will be running through the electrical check list with the multimeter. But I don't know if this is the right path.

I do have a minor theory regarding the radio though. This past Friday I was riding in the car and I was pushing the radio button just as a futile attempt to see if it would work, of course it didn't. But what if I accidentally left it "on". As in I turned it into a state of power draw despite not actually working and due to the messed up nature of the whole system it doesn't stop the draw when the car is turned off, slowly killing the battery. It's very left field but I have a nagging idea that may be a possibility.

The car itself was pre-owned before I got it in around 2022. It has 300,000 miles and the engine was rebuilt at some point. The only serious things I have replaced was the blower motor, wiper transmission linkage and the front driver side wheel hub. She has many scars but before this she was very reliable.

I apologize for the ramble, I'm just trying to wrap my head around all this. Any tips or idea if I'm anywhere near the right track would be appreciated. Would it even be safe to just shove a new battery in to at least get it home?

 

to the forums!

I think your original issue was the broken battery terminal clamps. This made for a bad connection and poor charging. So check your work on the new clamps.

You mentioned that you thought about jump starting, but it's unclear if you actually did so. The proper way to do so from under the hood is positive cable to the front lug on the side of the fuse block, negative cable to the stud on the strut tower. This front lug(should have a red cover over it that flips out of the way) should have 2 large cables attached to it, they may be red or black. The rear lug should have 1 small cable attached, red. If you attach a jumper cable to this rear lug, it can cause many electrical issues.

Inside the fuse block are 4 small bolts. With a 7mm tool, these must be extremely tight.

I don't think it's possible for a 12V battery with only 6 volts to have 850 CCA?

 

Thank you for the welcome and advice!
I will take a look at those terminals when I get back to the car.

I did attempt a jump start but and she was tried a little bit but gave up quickly to just a few clicks as if I didn't have the jump pack on it. Though I will say I was jumping from the battery so maybe that is my problem.

I will bring a 7mm with me and tighten those before starting the car up again.

Im not quite sure what exactly the specs were for the old battery, it was for sure an AGM and at least the sticker showed 850 CCA. Though I haven't looked at it recently. It was a beefy battery and likely not meant for the HHR.

 

There might be a fusible link between the starter and alternator, check it for continuity.
Did you check the serpentine belt and the AC compressor? If the compressor is locked up the belt will slip causing the alternator low output.
The charging should be between 12v and 15v (engine running) engine off the battery should be above 12.5v.
Don't agonize about CCA. Voltage matters.

 

I didn't think about the AC possibly seizing until you mentioned it. I suppose that could explain the weak AC that she reported. I take it I should grab a fresh battery and see check that. I also take it if that is the issue, I'm not driving this thing home without a lot of replacing?

 

Jumping directly from the battery is fine. Check that those lugs on the side of the fuse block are as they should be.

Donbrew's thoughts are very good also.

 

Alright folks, thank you for all of your tips. I went to Walmart and the folks said the battery was good, it managed to charge I guess overnight when it was off everything. I don't know. But I brought the battery back, cleaned off the the posts. I went out and checked the connections on the fuse box. I was able to spin the AC pulley a bit. I wanted to check the alternator's plug connector but grabbed the wire and nut and found I could twist it by hand. so I tightened that down too. I popped the battery back in and voila that mfer turns on, there is so far no check engine light. I took it for a drive around the block, seems to be like normal.

I also just want to add that I appreciate you guys and the assistance you've given over the years. Thank you.