The invention discloses a charger for storage batteries. The charger comprises an AC power source input circuit, a DC power source input circuit, a pre-charging circuit, an inverting circuit, a voltage isolation circuit and a first rectification circuit; the input end of the AC power source input is connected with an AC input power source of the charger; the input end of the DC power source input circuit is connected with a DC input power source of the charger; the output end of the DC power source input circuit is connected with the output end of an AC power source input circuit; the pre-charging circuit is connected with the output end of the AC power source input circuit; the inverting circuit is connected with the pre-charging circuit and is used for converting DC outputted by the pre-charging circuit into AC; the voltage isolation circuit is connected with the inverting circuit and is used for performing voltage isolation on the AC outputted by the inverting circuit; and the first rectification circuit is connected with the voltage isolation circuit. With the charger for the storage batteries of the invention adopted, either the AC power source or the DC power source can be used for charging the storage batteries, and therefore, the practicability of the charger can be improved.