Mohammad Masoum - Department of Electrical Engineering Iran University of Science & Technology Narmak, Tehran, ۱۶۶۴۵, Iran.
Saeed Zamani - Advance Electronic Research Center Tehran, Iran.

The ultra fast charging capability of Ni-Cd batteries are used to present a safe and fast charging algorithm which prevents battery damages and maximizes it's life time. The algorithm uses a combination of battery voltage (amplitude and slop), operating temperature and charging time slope to achieve a safe charging process. Before any charging action, battery state is determined, battery is intentionally discharged (to avoid memory effects), slowly charged to a safe voltage level (to maximize it's life time), and then charged very rapidly. For terminating the charging action, accurate end-charge techniques are used (to avoid over charging) and finally, the battery enters the trickle mode. Based on the proposed algorithm, a fast microprocessor Ni-Cd battery charger is constructed and tested. Measured results are demonstrated and compared for two fast charging techniques (pulsed-current and ReFlex) along with two end charge detection approaches (-DV and Dt)

Battery charger, Ni-Cd, Fast charging, Microprocessor