thebull55

Very interesting. I was not aware of that. The local GMC stealer is very easy to deal with. I think I’ll stop by and have them hook it up. Thanks for the info. ?

The Duracell is on my short list for sure. The 15.5 was with only the radio on. I thought that seemed a little high. I think I will listen to chem_man and see if I can get it tested, just to make sure. Just don't want to go into winter unsure. Thanks!

I have a 2011 Sierra SL with a 4.8L. Battery age is unknown as it was there when I bought the truck. Over the weekend we were moving our kid into their dorm and I sat out front with hazards on and nothing else. When I went to leave battery didn't have enough umph to start they truck. Jumped it and started right up and was fine stopping a couple times on the way home. I let the truck sit overnight and then checked the battery. It read 13.3V and then 15.5V after starting the truck. No problems since. Was this a fluke or is the battery giving a warning shot before winter? I will probably just replace the battery before winter, but just wanted to know if I am missing something. Thanks!