|June 20, 2023
24 Volt 2000mA Desk Top NiCad and Nickel Metal Hydride Battery Chargers with universal 100-240 VAC Input
TUV, CE marked, lowest cost quality charger for NiMH and NiCad batteries.
This a dT/dt and -dV fast battery charger with a microprocessor controlled charge and sense LED display and preset time-out. 100-240 VAC 60Hz / 50 Hz input, with fixed AC cord connector. Universal desk-top AC charger charges packs containing 20 cell, 24VDC NiMH or NiCad battery packs with peak charge detection.
Note on discharge function: this charger used to have a discharge function. Our tests have shown that this is no longer needed with these smart chargers and modern battery chemistries, and serves only to wear the battery out faster. So these chargers no longer have the discharge function.
Thermistor This charger will work only if you have a thermistor attached to the pack. The thermistor monitors the temperature and detects when the battery is fully charged. When the current stops charging and starts to generate oxygen ions (which are recombined at the electrodes) more heat is generated. Many NiCad and NiMH battery packs already have the thermistor installed, the NTC type, 10K and B=3950 is the industry standard. If you don't have a thermistor in the pack you need to add one. The bead of the thermistor needs to be in thermal contact with the battery. Good results will be obtained if it is taped to one of the cells, where it will detect if that cell is full. Any cells that are not yet full will be topped up during the subsequent trickle charging stage. Electrically the thermistor is connected between the thermistor terminal of the battery charger connector and the negative terminal, but it doesn't matter which side of the thermistor is attached to the thermistor terminal. A voltage is applied through this terminal and the resistance is measured by the charger by detecting the amount of current flowing through the thermistor to the negative terminal.
Inexpensive desk top Nicad and NiMH Battery Charger with peak charge control circuit, universal AC input version.
Single LED changes color to indicate state of charge.