The invention relates to a photovoltaic
cell -DC / DC boost conversion charge method which belongs to battery technique field. The method includes: 1) a portable equipment accumulator
voltage is detected by a
voltage sensor, when lows to full charge capacity, the
voltage sensor makes DC / DC
boost converter starting DC / DC conversion, and
electricity quantity flows from photovoltaic current to
lithium battery for charging; 2) when the portable equipment accumulator is in full charge capacity state, accumulator need not charge again, the
voltage sensor makes DC / DC
boost converter forbidding DC / DC conversion, thereby, the portable equipment accumulator is protected and over charge phenomena is prevented. The method can be realized simply, and has short reaction time, high efficiency,
overvoltage protection and anti-counterblast protection.