Technical Data Sheets:
Nickel Metal Hydride smart battery charger, 16W
Nickel Metal Hydride smart battery charger, 16W, Wall Plug In
Nickel Metal Hydride smart battery charger, 35W
Nickel Metal Hydride smart battery charger, 65W
Stocked NiMH / NiCd charger catalog
Input cordsets

When fast charging Nickel based battery packs, a charge control is required within the NiMH battery charger to properly charge the batteries. Relative voltage control using the –dV principle has proven to be a very reliable cut-off method.

This termination technique is based on the fact that there is a slight drop in voltage in NiMH / NiCd batteries when they are fully charged, provided they are being charged with DC current. The NiMH battery charger senses the voltage reduction when the battery voltage has reached a certain level in relation to the maximum recorded value. In the event that this does not occur, the charger has a built in safety timer which interrupts the charging after a set period of time and prevents the batteries from overheating.

There is a tendency for the voltage of some batteries to drop during the first stage of the charging cycle. This applies in particular to batteries which have gone for a long time without being charged. Therefore, NiMH battery chargers have a start timer which prevents –dV sensing during the first few minutes of the charging cycle. The NiMH cells have a lesser drop in voltage than NiCd cells, however, most battery manufacturers recommend the same –dV sensing for both NiMH and NiCd batteries. When charging NiMH batteries, it is recommended that temperature sensing termination be used in addition to –dV sensing (the pack must have a thermistor included in its assembly.

These standard fast chargers use –dV detection by default. Because the chargers are equipped with a computer programmable microprocessor, they can be readily programmed by Cell-Con to fit a variety of Nickel Metal Hydride specifications. These charge detections include (one or more options can be combined):
-dV
dT/dt
0dV
Timer only

In addition, adjustments can be made to:
Safety timer
-dV threshold
Temperature gradient

Cell-Con also provides custom charger solutions, stocked Lithium Ion battery chargers, stocked Lead Acid battery chargers, and stocked multi-position / modified stocked chargers.

Call us at 800-771-7139 or contact us online to learn more about our Nickel Metal Hydride based chargers, or visit the technical data sheet pages above.