Ni-Cd battery charger according to their degree of technical improvement can be divided into many types, the simplest one is to slow the laptop battery Chargers, Chargers general this is a fixed output voltage of DC transformer, depending on the size of the charge current transformer Plus internal resistance or the size of resistance.

Slow charging for nickel-hydrogen batteries or nickel-cadmium hp laptop battery is negative, because the process of charging the heat will continue to accelerate the aging batteries. Cheap charger normally does not slow the charge current to a good filter, so the battery of serious damage to many.

For nickel-hydrogen batteries and nickel-cadmium Presario V2000 battery charger optimize the design of the rapid technically much more complex, the Chargers general design of current regulator, the pressure limiting protection circuit and charge control circuit. Rechargeable batteries under the control circuit to the temperature (and / or terminal voltage) calculation of the charge current and charge time, and make the appropriate adjustment charge until the end of the process.

Determine whether the battery fully charged, at present there are two standard algorithm, often referred to as "negative voltage Act" (- жд V) and the "temperature method" (жд T). To use these two algorithms, the charge current must be not less than 0.2 C, so as to allow the Pavilion DV1000 battery have a significant temperature rise or voltage drop, thereby determine charging effect. (As shown in Figure 1)

Some of the traditional nickel-cadmium battery chargers to be transformed so that it can be for nickel-hydrogen batteries and / or lithium-ion batteries. It was found that as long as a few changes, nickel-cadmium Pavilion ZV5000 battery charging method can be used for nickel-hydrogen batteries.

However, to make an adaptation of three battery chargers at the same time is not so easy. First, it must pass a certain way (such as the selection switch, EPROM, etc.) to identify lithium-ion Pavilion DV4000 battery; Second, a more sophisticated reference source to design pressure limiting protection circuit; third, to use the continuous current - for charging voltage algorithm (CCVV).

Because of backward compatibility, this design concept has been widely used, it allows people to enjoy the performance of lithium-based batteries advantage, with the safety of lithium-ion batteries replace the "hot personality" of lithium batteries for high prices The lithium-ion Presario V2000 battery protection circuit at an early date and its related market cleared the obstacles.