2014 Malibu: replace battery
Posted: Mon Jan 26, 2026 10:09 pm
I noticed the starter sounded a little slow but no other symptoms. Decided to test the battery.
Tested in bad health AND low on charge. Yikes. I ran a repair cycle (which I guess also charges it). The result was this:
I did have an anomaly with the S550 and testing the battery in circuit. So I disconnected it and retested. Same.
Decided to just remove so I could head to the parts store and avoid paying the core. There was only one problem. It was a PITA to remove. They put all kinds of wiring and nonsense right on top of the battery. Not just on top but actually clipped to the battery. I had to pull the PCM out of the way and disconnect some stuff. Cracked a few plastic things. Finally got it out.
Turns out it's a Group 49 AGM just like the rear battery in my S550. I went with an O'Reilly battery this time instead of a Diehard from Advance. I don't really know why as the Diehard I think has another 50 CCA and seemed to be holding up in my S550. I guess I like O'Reilly. I think they both have the same 4 year warranty. Or something something another data point. FWIW, the parts store tester agreed with my replacement decision.
Tested the new one. Reassembly was easier since I had already fought with it to get it out so I knew the combo to get it back in. Still terrible.
This ring is likely a crash rating improvement thing. It sits under the positive terminal and likely keeps th battery from becoming a projectile in an accident. Tested in circuit and it's still good. Oh yeah, I think it was the original battery. My evidence is it was a GM battery and none of the plastic or other things I had to touch showed any signs of anyone angrily snapping stuff. Turns out a big-ass Group 49 AGM can last a long time when all it has to do is crank a 2.5L 4 cylinder. This car does have stop/start. It's always been hit or miss so it'll be interesting to see if they changed. I should scan to see if anything is complaining about the rear battery.
I suppose I could also test the little battery in the trunk.
Tested in bad health AND low on charge. Yikes. I ran a repair cycle (which I guess also charges it). The result was this:
I did have an anomaly with the S550 and testing the battery in circuit. So I disconnected it and retested. Same.
Decided to just remove so I could head to the parts store and avoid paying the core. There was only one problem. It was a PITA to remove. They put all kinds of wiring and nonsense right on top of the battery. Not just on top but actually clipped to the battery. I had to pull the PCM out of the way and disconnect some stuff. Cracked a few plastic things. Finally got it out.
Turns out it's a Group 49 AGM just like the rear battery in my S550. I went with an O'Reilly battery this time instead of a Diehard from Advance. I don't really know why as the Diehard I think has another 50 CCA and seemed to be holding up in my S550. I guess I like O'Reilly. I think they both have the same 4 year warranty. Or something something another data point. FWIW, the parts store tester agreed with my replacement decision.
Tested the new one. Reassembly was easier since I had already fought with it to get it out so I knew the combo to get it back in. Still terrible.
This ring is likely a crash rating improvement thing. It sits under the positive terminal and likely keeps th battery from becoming a projectile in an accident. Tested in circuit and it's still good. Oh yeah, I think it was the original battery. My evidence is it was a GM battery and none of the plastic or other things I had to touch showed any signs of anyone angrily snapping stuff. Turns out a big-ass Group 49 AGM can last a long time when all it has to do is crank a 2.5L 4 cylinder. This car does have stop/start. It's always been hit or miss so it'll be interesting to see if they changed. I should scan to see if anything is complaining about the rear battery.
I suppose I could also test the little battery in the trunk.