To prevent exhaustion of a battery.
The power supply device 1 supplies electric power from a power generator 12 to a plurality of loads 5, 6 and 7 via the battery 2. The power supply device 1 comprises switches 3 and 4 opened between the battery 2 and the loads 6 and 7, a stop detecting means 1c for detecting that a charging operation to the battery 2 from the generator 12 stops, a battery residual amount detecting means 1a for detecting residual amount of the battery 2 at a stop time of the charging operation, a range determining means 1e for determining a range including the battery residual amount at a stop time of a power generation operation for a plurality of ranges into which the maximum capacity of the battery 2 is divided in the level direction, and a first power supply stopping means for opening a switch other than the switch connected to the load corresponding to the range including the battery residual amount.
SUMITOMO WIRING SYSTEMS
SUMITOMO ELECTRIC INDUSTRIES
Kyuichi Ueki
Takao Ito
Next Patent: CAB MOUNTING STRUCTURE OF CAB OVER VEHICLE