Nicd Nimh Battery Charging Circuit PIC16F876 Delta-Peak

With the battery charger circuit controlled by PIC16F876, 150 ma to 6000 ma power Nicd, Nimh batteries can be charged, the power of the circuit is between 50 ma and 2 amps. 2 mosfets (irf9540, smp60n) are used in the pic output, the batteries are charged quickly, and there is also a shock and recovery system for batteries whose voltage is below 0.4 volts, the circuit is partly easy to make but has a very detailed working system (Delta-Peak, pwm etc.)

The PIC controls a constant current source that charges the battery at approximately C/3, and a discharge constant current sink that discharges the battery at C. (C is a current corresponding to the battery capacity/hour, for example 700mA for a 700mAh battery.)

The constant current source for charging the battery is built with an OPV (LM358) driving a P-channel MOSFET (IRF9540). It regulates the current so that a voltage drops across the measuring resistor R19 (0.47 ohm) that is the same as the voltage at the positive input of the OPV.

The discharge circuit is a constant current sink using the same OPV, but this time it drives an N-channel logic level MOSFET (SMP60N03-10L) that discharges the battery through sense resistors R16..R18. It regulates the current so that a voltage drops across the measuring resistors (0.157 ohms) that is the same as the voltage at the positive input of the OPV. This ensures that the discharge current is always three times the charge current.

Both the charge circuit and the discharge circuit are normally blocked by the PIC via D1&D2 and are only opened when charging or discharging.

Also in the charging circuit on the circuit operation status 2×16 LCD, displaying information about the settings prepared by assembly source software. Asm and hex file there. Similar applications software method or some parts in the circuit can split your business.

Source: http://www.sprut.de/electronic/pic/projekte/akku1/akku1.htm
http://www.sprut.de/electronic/pic/projekte/akku2/akku2.htm