I have a Dell XPS 12 9q33 laptop that arrived in a state where it will shut off after a minute or two when there is no AC adapter plugged in. The battery was supposedly fine according to diagnostics, but after some research I came to the conclusion that one of the cells was dead and that's what was causing the issue. I just bought a new battery and installed it with the same issue. Any ideas? The laptop is out of warranty and I tried to contact Dell. They said they didn't have the computer's service tag on record and refused to help me. Any ideas would be great.