Tracks the battery charge percentage and switches the mains as set by the user. Draws a graph for checking over time.

This was made when the laptop battery under test was in poor condition, as can be seen by the steep discharge rates on the graphs. It was found that in this state, a fast discharge and much slower charge caused overheating of the charging circuit, which powered off the laptop automatically. The option to switch off charging after 100% reached (as well as values below 100%) was included and this has stopped the power-off from happening. The user can view and print previous graphs for comparisions. 

 

Switching off at 100%:

 

 

Switching off 25 minutes after reaching 100%:

 

 

Hardware, diecast box with mains in and out and USB lead: