A charging method may be applied to a charging apparatus. The charging method may include: in the discharge stage, obtaining a current voltage of the energy storage battery in each energy storage unit; determining, based on the current voltage of the energy storage battery in each energy storage unit, a first voltage output by the first DC/DC converter in each energy storage unit, where the first voltage output is inversely proportional to the current voltage of the energy storage battery; and sending the first voltage to the first DC/DC converter, so as to cause the energy storage battery to receive, at the first voltage via the first DC/DC converter, electrical energy released by the traction battery.