A Possibility of the State of Charge Monitoring of the Lead-Acid Battery by Means of Current Pulses of a Given Value

The article presents the results of testing the internal resistance changes of the lead-acid battery as a function of accumulated charge. In order to measure the internal resistance, a short current pulses of a given value at specified time intervals were forced in the battery. The internal series resistance of the battery equivalent circuit was determined as the quotient of the measured voltage jump to the value of the current pulse. The measurements were carried out in time windows of a given length. The experiment showed that the internal resistance during discharging is monotonically variable in relation to the remaining charge in the battery and this method can be used to estimation the state of charge of the battery. In contrast, during loading, no such dependence is observed.