| 摘要 |
A battery charger and method are disclosed for charging alkaline, Ni-Cad and zinc-based batteries, particularly sizes N, AAA, AA, C and D. For batteries rated at about 1.25 volts to about 15 volts, the battery charger and method provide a constant charging current of between about 0.28 ma to about 1.5 ma per gram weight of the battery. A constant current circuit under control of a controller provides the constant current to the battery under charge. A reference voltage generator generates reference voltages as the battery is being charged while the controller frequently monitors the battery voltage and compares it to the reference voltage. A substantially constant current is supplied to the battery while a reference voltage greater than the battery voltage is provided. Thereafter, as the battery voltage increases, the reference voltage is incremented up to a predetermined maximum reference voltage. The controller causes the constant current circuit to terminate the supply of current to the battery when the reference voltage reaches the predetermined maximum, or when the battery voltage does not increase during charging to be greater than a first or a subsequent reference voltage during a predetermined charging time period. The controller may also cause the constant current circuit to supply from time to time a substantially constant test current to the battery which exceeds the charging current by from about 2.5 % to about 25 % for up to a predetermined testing time period, and terminate the supply of current to the battery if the test current increases by greater than a predetermined amount within the predetermined testing time period. The battery charger may at the same time charge batteries of different sizes, and includes a separate constant current circuit for each battery in the battery charger. Each battery is constinuously supplied with charging or testing current as determined by the controller, and the controller controls charging of each battery independently of the charge condition of any other battery. A separate controller may control each constant current circuit, or a microprocessor may control all of the constant current circuits.
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