In 2003 I became aware of the TEA1102. With this controller, nickel cadmium, nickel metal hydride, lead gel as well as lithium ion cells can be charged with relatively few components.

For NiCd or NiMh batteries the charger works with delta peak detection, Lithium Ion and lead acid cells are charged with constant current / constant voltage. In addition, an overtemperature protection and a timeout are available.

The circuit was mostly taken from the datasheet, the three solder bridges, R6 and R7 are wired according to battery type and capacity and charging current.

Since this layout was my very first self-etched one, there are unfortunately no documents left.