Abstract: The invention presents a method for estimating a direct current internal resistance of a battery, which defines a depth of discharge detection interval including a first threshold and a second threshold. When the battery is discharging, a currently battery voltage are periodically measured, a currently depth of discharge is calculated, and an open-circuit voltage is queried. The currently battery voltage is subtracted from the open-circuit voltage to obtain a voltage difference. The voltage difference is continuously accumulated to obtain a currently accumulated voltage difference. The currently depth of discharge reaches the first threshold or the second threshold, the currently accumulated voltage difference is a first accumulated voltage difference or a second accumulated voltage difference.

Abstract: A battery pack burn-in test system comprising first and second interconnection circuits for electrically interconnecting a first and a second battery pack respectively to the system; a data communication bus for coupling to respective battery management integrated circuits (ICs) of the first and second battery packs; and a system management unit coupled to the data communication bus. The system management unit may control a charging of the first battery pack during a burn-in test from a discharging of the second battery pack.

Abstract: A battery pack burn-in test system comprising first and second interconnection circuits for electrically interconnecting a first and a second battery pack respectively to the system; a data communication bus for coupling to respective battery management integrated circuits (ICs) of the first and second battery packs; and a system management unit coupled to the data communication bus. The system management unit may control a charging of the first battery pack during a burn-in test from a discharging of the second battery pack.