| 摘要 |
An engine 100 comprise a first battery 101 and a second battery 102, a charge level sensor 106 and a control unit 105 which measures the charge level of the first battery 101 and causes the second battery 102 to charge the first battery 101 when the first batterys 101 charge level falls below a first threshold. The charge level of the second battery 102 may be monitored, and charging may only take place if the charge level of the second battery 102 is above another threshold. The battery-to-battery charging may only take place if the engine 100 is not connected to an external power supply 108. The charge level of the first battery 101 may be measured periodically, and the measurement frequency may vary according to the charge level or the rate of change of the charge level. The second battery 102 may have a higher voltage than the first, and may charge the first battery 101 through a DC to DC converter 109. The engine 100 may be in a vehicle. |
