Note: User Ian Abbott points out that there is actually no charging circuit, it does take a standard CR2032 battery. What I thought was recharging was probably the battery recovering after having been under a load.
There will be a lot of duplicate information between this video and the comparison to the HP 42s but I wanted to do one specifically focused more on reviewing than features. I'm still getting the hang of this whole video thing so please bear with my rambling and lack of focus :)