Lead acid, NiCd, LiIon fast battery charger schematic

The TEA1102x are fast charge ICs which are able fast charge NiCd and NiMH, SLA and Lilon batteries.

All battery types are initially fast charged with an adjustable high current. Fast charge termination depends upon the battery type. With NiCd and NiMH batteries the main fast charge termination will be the DT/Dt (temperature detection) and/or peak voltage detection and with SLA and LiIon batteries when the battery voltage reaches 2.45 or 4.1 V respectively.

The fast charge period is followed by a top-off period for NiCd and NiMH batteries and by a fill-up period for SLA and LiIon batteries. During the top-off period the NiCd and NiMH batteries are charged to maximum capacity by reduced adjustable charge current. During the fill-up period the SLA and LiIon batteries are charged to maximum capacity by a constant voltage and a gradually decreasing current. The fill-up and top-off period ends after time-out or one hour respectively.

After the fill-up or top-off period, the TEA1102x switches over to the standby mode. For NiCd and NiMH batteries either the voltage regulation or trickle charge mode can be selected. The voltage regulation mode is selected when the battery includes a fixed load.

Trickle charge prevents a discharge of the battery over a long period of time. For SLA and LiIon batteries the charge current is disabled during standby. The fast charge mode is entered again when the battery voltage reaches 1.5 V (SLA) or 3 V (LiIon).