Experiments in fast charging lead acid electric vehicle batteries

Several experiments were conducted at the University of Massachusetts Lowell battery evaluation laboratory in order to measure the battery's charge acceptance ability and the time necessary for it to be charged to reach 80% of its capacity. A high charging current source was connected to the batteries through a data acquisition system. The profiles of the charging current, capacity, temperature and battery impedance were recorded during the test. The time needed for each battery to be charged to 80% and full charge was also recorded. The results show that the charging acceptance varies depending on the type of the battery and its internal impedance. The time necessary to reach 80% of it capacity, as well as full capacity depends on the type of the battery too. Also, the results can be used to size a fast battery charger and the charging algorithm needed.