Here is presented a simple 500mA 4.1V or 4.2V Li-ion battery charger that is constructed with the MCP73826 linear charge management controller.
There are two versions of this
controller MCP73826-4.1 that is preset to a regulation voltage of 4.1V and MCP73826-4.2 with a preset of 4.2V.
The IC operates with input voltage between 4.5V to 5.5V. Typical applications are:
single cell Lithium-Ion battery chargers, personal data assistants, cellular telephones, hand held instruments, cradle chargers