When warming-up of a battery is in progress (S12), a battery charge state at the warming-up start time of the battery is set to a battery hold capacity SOChold (S14, S15), and a charge power for the battery is controlled so that a battery charge state SOC is kept at SOChold. When a present time is in a timer charge reservation time (S11), the charge power for the battery is controlled so that SOC becomes a full charge state SOCfull (S17). Even if SOC has a tendency to temporarily decrease due to a rapid increase of heater consumption power just after start of warming-up of the battery, by keeping SOC at SOChold (SOC=SOChold), SOC can reach a full charge state as intended during the timer charge reservation time. A proportion of charge using low-priced midnight power is increased to a maximum then running cost can be suppressed.