The flexibility of the Arduino platform means it can often be a drop-in replacement for circuits that would otherwise be surprisingly complex, while its power allows it to bring intelligence to scenarios that would normally be solved via brute-force. A great example of this can be found in the latest project of Electro-Labs' Abdulgafur Mujdeci: an add-on shield which turns an Arduino Uno into a programmable charger for lithium batteries. Frequently used in portable devices thanks to their high energy density, lithium batteries - both lithium-ion and lithium-polymer - require careful handling so as not to overcharge them, a task handled admirably by the Arduino - complete with user-friendly read-out on a recycled Nokia 5110 liquid-crystal display. Abdulgafur has included full schematics and circuit board design files, created in FabStream's free SoloPCB, and while the use of surface-mount components mean this isn't a project for the soldering novice it shouldn't prove too difficult for anyone with a little experience under their belt.
In this project, we are building a programmable single/multi cell lithium battery charger shield for Arduino. The shield provides LCD and button interface which let the user set the battery cut-off voltage from 2V to 10V and charge current from 50mA to 1.1A. The charger also provides the ability to monitor the battery status before and during charge.