10 - 30 minuten
No warning anymore when battery was low- just shut down when battery icon said 40%.
The photos were very helpful. I would have preferred that the computer and steps were photographed from same side. I needed to turn the computer around to match the photo and then it changed again (My spacial disorientation was successfully challenged as I just went ahead and transposed it in my head). The only trouble was in carefully getting the screws to seat properly before tightening. My son helped by realizing that the blue plastic on the threads had become bunched on the bottom of screw hole so he used one of your tools to gently scrape it out. Voila! New battery has some very visible dents in it along an edge but we took a photo of it in case that means something in the future.
Give tips on how to seat screws so that the threads don't get stripped- would be easy for a novice to force them. Turn them counterclockwise til feel them seat, then turn them clockwise to fasten but not all the way until other screws are in place. Tighten later when all are in.