A 5 hour NiCAD/NiMH battery charger
Current Status: Complete
Date: 27th August 2003
License: Creative Commons Attribution 3.0 Unported License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
This work is licensed under a Creative Commons Attribution 3.0 Unported License
This is a simple circuit to charge a 7.2V NiCad or NiMH battery in around 5 hours at 1/4 the cell capacity rate.
The charging current on the prototype was approximately 300mA.
The LED in the circuit comes on when a battery is connected to indicate that charging is in progress.
In the schematics I have shown Wago screw clamps for all power connections, you can use normal PCB holes.
This circuit has a 230V AC mains transformer. Only build this circuit if you are competent with AC mains powered equipment and the dangers involved.
Click the above image for a full schematic.
The prototype circuit was built using stripboard, so there is no PCB layout.
By Ian Stedman, 27th August 2003
Updated 27 September 2020