  A charging method for electric vehicle using multi battery series mode which
consisted of the following steps was introduced: the battery series is firstly
charged at a constant power with a charging current of I1. When the terminal
voltage over the battery series has reached the 1st threshold voltage, the
charging current will reduce to I2 and the power remains constant. When the
terminal voltage over the battery series has reached the 2nd threshold voltage,
the charging current will reduce to I3 and the power remains constant (the 2nd
threshold voltage is larger than 1st threshold voltage). When the terminal
voltage over the battery series has reached the 3rd threshold voltage, which is
the rated voltage of the battery series, the charging process is completed (3rd
threshold voltage is larger than 2nd threshold voltage). Contents in this paper
provide a charging method for electric vehicles using multi battery series mode
with high charging efficiency and security level.
