To provide a constant-current/constant-voltage charging method and its equipment which charges a plurality of lithium ion batteries or lead batteries to usable state, in a short time.

A plurality of channels CH-1-CH-4 are divided into a main channel for charge in which current limiting except constant current/constant voltage is not performed, and subchannels for charge in which current limiting by the maximum power by using excess power generated to the maximum charging capacity is performed. In this state, charging is performed. First, the channel CH-1 is used as the main channel, charge of lithium ion battery is started, and this main channel is used until the charging is completed. Immediately after that, the channel CH-2 is used as the subchannel, and charging is performed by supplying excess power. When the channel CH-2 reaches a constant voltage region, this channel is switched over to the main channel, and charge is performed by using the channel CH-3 as the subchannel. This switching is repeated until all the channels turn into main channels.