Electrical Malfunctions?

This is based on after i watched your video https://www.youtube.com/watch?v=6Tlg3JmgNSQ&ab_channel=2CarPros

I just paid a mechanic $60 (Canadian). He hooked up a scanner and said there were no error codes, but my battery charge was just a little down. If I take the cables off of the battery for a few minutes and reconnect them, the car will start. but i may or may not have functional windows, stereo, door locks and rear running lights. Air conditioning and environmental controls always work. I would appreciate any suggestions! Thank you!