Update: According to this comment on Dangerous Prototypes, the charger chip’s support for lithium ion charging is quite primitive, and so this project depends on the Arduino to properly manage the charging. Too bad.
ElectroLabs has published a nicely documented programmable single/multi cell lithium battery charger shield for Arduino. It is based on the LT1510 Constant Current/Constant Voltage Battery charger IC.
- Display for battery/charge status and configuring charging parameters
- 50mA 10 1.1A charging current.
- 2-10V charge cut-off voltage
Those voltages don’t make a whole lot of sense for Lithium Ion, but it appears the charger IC they are using also works with other chemistries.
I don’t know the BOM cost, but an assembled version is $75 on Tindie (ouch).
I don’t think I’ll be building one of these, but I am very interested in having examples of using commercial charger ICs outside their default configurations.