There are a number of charging regimes used in industrial and domestic battery charging equipment. They include: Contant Voltage often called Constant potential, 3 stage charging and Constant Current. Constant potential chargers are used in standby and cycling application, constant current chargers are used on Nicad or NiMH cells and 3 Stage chargers are used on electric vehicles such as fork lift trucks with deep discharge duty cycles.

You can see the difference between all three methods by clicking the links below to see an animated demo of each regime. Note that each animation is a very close approximation of actual battery and charger performance.

The animation reflects a typical battery charger instrument panel displaying DC Volts and DC Amps. By observing the instruments, you can see the relationship between the battery/charger voltage and the charging current from which the actual control function can be realised.

The regimes on these pages demonstrate the basic attributes of each charging method. More complex techniques are sometimes applied, particularly to a constant current charging system. A typical example is the switch tripping regime.

Each sequence is on a repeating cycle and starts with 21V displayed on the Voltmeter.

Constant Potential Demo:
Constant Current Demo:
Switch Tripping demo
3 Stage Charging Demo: