I built a simple Lithium-ion battery charger using a PIC and some basic components. It simply charges the cells up to ~4.1 volts using a constant current. This isn't the best method for storing the optimum amount of energy, but it is simple, and it may even increase the working life of the cells.
Here's the circuit diagram for the device:
I prototyped the circuit and did the initial programming on a breadboard:
I assembled the device up on some stripboard to get a quick working charger:
The source code for this project is available on Github.
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