OK, so did the technician that "re-imaged" it set up the power configs the way you wanted? I have seen power setting say to turn off if battery power reaches 90%. Could this be the issue? Perhaps your laptop is missing an all important update that was not applied with the "re-image"!
Typically PC are "re-Imaged" because the technician has no idea of what is wrong. When the re-image is complete, the same issues are present as the OS is not problem, but the hardware itself is at fault, and the technician has no idea of what they are doing!!