Vessel power supply system
A vessel power supply system for a vessel including a propulsion device that includes an engine and a generator driven by the engine to generate electricity, includes a first battery that supplies power to the propulsion device, a second battery that supplies power to accessories of the vessel, a first open circuit voltage sensor that detects an open circuit voltage of the first battery, a second open circuit voltage sensor that detects an open circuit voltage of the second battery, and a switch that is turned on/off to open and close a current path between the first battery and the second battery.
1. A vessel power supply system for a vessel including a propulsion device that includes an engine and a generator driven by the engine to generate electricity, the vessel power supply system comprising:
a first battery that supplies power to the propulsion device;
a second battery that supplies power to accessories of the vessel;
a first open circuit voltage sensor that detects an open circuit voltage of the first battery;
a second open circuit voltage sensor that detects an open circuit voltage of the second battery;
a first switch that is turned on/off to open and close a current path between the first battery and the second battery; and
an on/off switch disposed in a power line that connects the propulsion device to the first battery, the on/off switch including a first end connected to the first battery and a second end connected to the propulsion device; wherein
the first switch is disposed in a current path between the second battery and the first end of the on/off switch such that the second battery is connected to the propulsion device via the power line in parallel with the first battery when the on/off switch and the first switch are both on, and that the second battery is disconnected from the propulsion device when either the on/off switch or the first switch is off.
2. The vessel power supply system according to claim 1 , wherein
the second battery is connected to the propulsion device via the current path; and
when the first switch is turned on/off, the second battery is connected to/disconnected from the propulsion device.
3. The vessel power supply system according to claim 1 , further comprising a switch controller configured or programmed to control the first switch.
4. The vessel power supply system according to claim 3 , further comprising a main switch that is able to supply power to the propulsion device and to be turned off by the user to stop supplying power to the propulsion device; wherein
the switch controller is configured or programmed to turn the first switch off when the main switch is turned off.
5. The vessel power supply system according to claim 4 , further comprising a start determining processor configured or programmed to determine whether the engine of the propulsion device has started; wherein
the switch controller is configured or programmed to turn the first switch on when the main switch is turned on and the start determining processor determines that the engine has started.
6. The vessel power supply system according to claim 5 , wherein the start determining processor is configured or programmed to determine whether the engine has started based on a rotational speed of the engine or a circuit voltage within the propulsion device.
7. The vessel power supply system according to claim 1 , further comprising:
a first storage that stores a first open circuit voltage value detected by the first open circuit voltage sensor when the first switch is in an off state; and
a second storage that stores a second open circuit voltage value detected by the second open circuit voltage sensor when the first switch is in an off state.
8. The vessel power supply system according to claim 7 , further comprising:
a first battery remaining level calculator that calculates a first battery remaining level of the first battery based on the first open circuit voltage value stored in the first storage and an integrated value of a current flowing into/out of the first battery; and
a second battery remaining level calculator that calculates a second battery remaining level of the second battery based on the second open circuit voltage value stored in the second storage and an integrated value of a current flowing into/out of the second battery.
9. The vessel power supply system according to claim 8 , further comprising a charging circuit that charges the first battery and the second battery with electric power generated by the generator; wherein
when the first switch is on and the first battery remaining level calculated by the first battery remaining level calculator becomes lower than a first threshold value, the first switch is turned off.
10. The vessel power supply system according to claim 9 , wherein, when the first switch is off and the first battery remaining level calculated by the first battery remaining level calculator exceeds a second threshold value that is equal to or higher than the first threshold value, the first switch is turned on.
11. The vessel power supply system according to claim 9 , further comprising a charge limiter that limits charging by the charging circuit when the first battery remaining level calculated by the first battery remaining level calculator is equal to or higher than a third threshold value that is equal to or higher than the first threshold value and the second battery remaining level calculated by the second battery remaining level calculator is equal to or higher than a fourth threshold value.