Abstract: A battery capacity and usage system, applied to an electric powered boat. A battery monitor is controlled by a micro-controller which includes a non-volatile memory for storing a lookup table. The lookup table comprises a database of characteristics of various batteries, including a relationship between the capacity and the charged voltage, the driving current and remaining hours of usage. The load of the battery is measured by a hall effect device. By monitoring the current micro-controller calculates the remaining time of the battery is obtained from the lookup table and displays the results on a digital readout installed on dashboard of the electric powered boat.

Abstract: A battery capacity and usage system, applied to an electric powered boat. A battery monitor is controlled by a micro-controller which includes a non-volatile memory for storing a lookup table. The lookup table comprises a database of characteristics of various batteries, including a relationship between the capacity and the charged voltage, the driving current and remaining hours of usage. The load of the battery is measured by a hall effect device. By monitoring the current micro-controller calculates the remaining time of the battery is obtained from the lookup table and displays the results on a digital readout installed on dashboard of the electric powered boat.

Abstract: A combination changing method is used in an access control system which includes one or more keys encoded at a central console with a function information code, a key identification information code, an operation select information code and a two-field key combination information code and one or more locks having at least one memory level in which a lock identification information code and a lock combination information code are stored. A key is initially inserted into a selected lock and the data from the key is transferred to the lock. The lock identification information code is first compared with the key identification information code. If there is no correspondence, power to the lock is turned off for a set period of time. If the identification information codes correspond, a test field of the key combination information code is compared with the lock combination information code. If these correspond, the lock opens.