Development of multi-type secondary-battery charger/discharger by arbitrary current waveform

A cost effective circuit to charge and discharge secondary batteries by an arbitrary current waveform is developed for investigating deterioration characteristics of the batteries. A charging management integrated circuit (IC) is employed for controlling both charging and discharging because there are few ICs to control the discharging of the batteries. The circuit configuration with the common ICs reduces the cost of the test system. This system can easily deteriorate the secondary batteries by a computer controlled current waveform. The developed circuit enables to charge/discharge different kinds of batteries such as series-connected lithium-ion (Li-ion), nickel metal hydride (Ni-MH) and lead acid (Pb) batteries with nominal voltages from 2 to 9 V.