Happy to get a bargain with a refurbished Hp Elitebook 840 G4 w/Win10, but it arrived with apparently the original (2018) battery.  While it charges to 100%, it doesn't last even four hours.  So now will look for and purchase a qualified replacement battery.Otherwise, the laptop was in very good condition and provides what I need for my work. I'm sorting through various updates to the software and hardware. Have hit a few obstacles -- the laptop wouldn't turn on after a driver update, so I plugged it in.Might have to do a factory reset, and then update (and hope the updates don't screw things up again). I'm my own tech support so hoping not to be disappointed returning to an Hp laptop again and its known battery shortcomings!