5 Hour NiCad Charger

A 5 hour NiCAD/NiMH battery charger
Current Status:   Complete
Date:                 27th August 2003
License:            Creative Commons Attribution 3.0 Unported License
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License
Design summary


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.

Warning

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.

Partslist

Part

Value

Device

Package

Description

C1

1000uF

CPOL-EUE5-13

E5-13

Electrolytic capacitor

C2

100nF

C-EU050-030X075

C050-030X075

Ceramic disc capacitor

CN1

BATT

W237-02P

W237-132

WAGO SREW CLAMP

D1

1N4004

1N4004

DO41-10

DIODE

D2

1N4004

1N4004

DO41-10

DIODE

F1

200mA

SH22,5A

SH22,5A

20 mm fuse holder, PCB mount

MAINS

W237-02P

W237-132

WAGO SREW CLAMP

R1

120

R-EU_0309/12

0309/12

1/2 W resistor

R2

15R

RKH206-8

KH206-8

5W power resistor

TR1

EI30-2

EI30-2

25VA 12Vx2 TRANSFORMER

U1

LED5MM

LED5MM

A 5 mm LED



Schematic Diagram

Click me for the full schematic

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 08 July 2017