Abstract: A battery charger monitors an open-circuit voltage across the battery and the rate of change of temperature of the battery to determine a time to terminate the process of charging the battery. Charging proceeds in four stages. In the first stage the open-circuit voltage of the battery is monitored until such voltage crosses a threshold value. In the second stage, the rate of change of battery temperature is monitored to determine a reference value, for example, a minimum of the monitored rate. In the third stage, the rate of change of battery temperature is again monitored to identify a time when such rate exceeds the reference value by a predetermined amount. In the fourth stage, power supplied to charge the battery is limited immediately after stage three or a predetermined time after stage three for example by reducing the charging current to a trickle-charge level or by reducing the voltage by about 100 mV.

Abstract: A battery charger monitors an open-circuit voltage across the battery and the rate of change of temperature of the battery to determine a time to terminate the process of charging the battery. Charging proceeds in four stages. In the first stage the open-circuit voltage of the battery is monitored until such voltage crosses a threshold value. In the second stage, the rate of change of battery temperature is monitored to determine a reference value, for example, a minimum of the monitored rate. In the third stage, the rate of change of battery temperature is again monitored to identify a time when such rate exceeds the reference value by a predetermined amount. In the fourth stage, power supplied to charge the battery is limited immediately after stage three or a predetermined time after stage three for example by reducing the charging current to a trickle-charge level or by reducing the voltage by about 100 mV.

Abstract: A rechargeable battery includes one or more rechargeable cells and means for providing information to control charging. Information is provided in a form for being read or sensed by mechanical, optical, electromagnetic, or electronic techniques including combinations of these techniques. The information may indicate battery performance history, present state of the battery, and parameters for how it may be charged. As to performance history, the information may include, for the battery or a cell of the battery, indicia describing: one or more previous charging or discharging processes, of the last charging process, of the last discharging process, of the time period lapsed since the last charging or discharging process. The information may include indicia of the present charge state and condition of the battery or its individual cells.

Abstract: A method of charging rechargeable batteries with a switch mode power supply, the method comprising determining one or more battery charging parameters, and controlling the power output of the switch mode power supply by digitally generating a gate signal for controlling opening periods and closing periods of a switching means of the switch mode power supply, each of the durations of the opening periods and the closing periods of the switching means, respectively, being determined in response to the determined one or more battery charging parameters and one or more charging process reference values. In particular, a method is proposed of controlling the duty cycle of a switch in the switch mode power supply during charging of the battery based on determinations of one or more characteristic charging parameters of the charging process and comparisons of determined parameter values with desired parameter values.

Abstract: In a system and method for charging a rechargeable battery having a protection circuit, the rechargeable battery operates according to a model that includes an ideal battery and an internal resistance. In the model, an electrode voltage develops across the ideal battery. An internal voltage drop equal to the difference between this electrode voltage and the battery voltage is developed across the internal resistance. The battery is charged with a charging voltage that may exceed the threshold voltage and the electrode voltage. The charging system and method ensures that (1) the voltage at the protection circuit is kept below the threshold voltage and (2) the electrode voltage is kept below the end-of-charge voltage.

Abstract: In order to optimally control the charging of a rechargeable battery of one or more cells to ensure that full and rapid charge is achieved without damaging the battery, a maximum safe value (or sequence of values during the charging process) for one or more charging parameters is determined during a test charge, and subsequent charges of the battery are performed without exceeding the predetermined maximum value(s) for the charging parameter(s). Among the charging parameters contemplated for use are: the charging voltage potential placed across the battery terminals, the charging current supplied to the battery, the temperature of the battery cell and internal pressure of the battery cell as well as rates of changes of the parameters.

Abstract: In order to optimally control the charging of a rechargeable battery of one or more cells to ensure that full and rapid charge is achieved without damaging the battery, a maximum safe value (or sequence of values during the charging process) for one or more charging parameters is determined during a test charge, and subsequent charges of the battery are performed without exceeding the predetermined maximum value(s) for the charging parameter(s). Among the charging parameters contemplated for use are: the charging voltage potential placed across the battery terminals, the charging current supplied to the battery, the temperature of the battery cell and internal pressure of the battery cell as well as rates of changes of the parameters.

Abstract: A rechargeable battery is charged by connecting the terminals of the battery to an electrical power source. In order to avoid overcharging and undue temperature increase in the battery cell, the course of a least one charging parameter, such as the increase rate of voltage, is surveyed during at least part of the process of charging the battery. This charging parameter surveyed is compared with a number of reference parameter courses representing idealistic or desireable processes of charging the battery for different starting states of charge of the battery. Such comparisons may for example be made by means of a microprocessor, which may also select the reference course with a starting state of charge similar to the actual starting state of charge of the battery. Thereafter the process of charging the battery may be controlled so as to approximate the course of said charging parameter to the selected reference course. The charging voltage may be limited to a maximum value (Vmax).