Battery charging method with stepped current profile with operating parameter compensation and associated charger

A battery charger for a DC battery comprising:

• means for applying a charging current to said battery;
• means for sensing battery voltage;
• means for sensing said charging current;
• means for monitoring change in an operating parameter of the battery during the application of the charging current;
• means for lowering said target voltage in proportion to and to compensate for the change in the parameter being monitored;
• means for comparing said battery voltage to the target voltage as said target voltage is being lowered;
• means for detecting full charge of the battery;
• means to control said charging current in response to input signals from said charging current sensing means, said comparing means, said monitoring means and said full charge detection means.

A battery charger for a DC battery comprising:

• means for applying a charging current to said battery;
• means for sensing a variable parameter including battery voltage;
• means for sensing and analyzing the change in said variable parameter;
• means for establishing a target voltage for said battery;
• means for maintaining said battery voltage not greater than said target voltage;
• means for stepping up the charging current during the initial phase of charging in accordance with the change in said variable parameter to provide a stepped current profile until the charging current reaches a maximum value;
• and
• means for applying said charging current until the battery is at full charge.

A method of charging a battery utilizing a variable charge current supply comprising the steps of:

• applying a charging current to the battery from said charge current supply;
• sensing battery voltage;
• analyzing the change in battery voltage over time;
• establishing a target voltage for said battery;
• maintaining said battery voltage not greater than said target voltage;
• stepping up the charging current during the initial phase of charging to provide a stepped current profile until the charging current reaches a maximum value;
• applying said charging current until the battery is at full charge;
• monitoring change in an operating parameter of the battery during the application of the charging current;
• lowering said target voltage in proportion to and to compensate for the change in the parameter being monitored;
• reducing said charging current by between 0.1-5.0 amps when said battery voltage equals the target voltage such that said reduction in said charging current causes a decrease in said battery voltage;
• repeating the steps of applying and reducing the current to provide a stepped down current profile until said charging current is reduced to the minimum value;
• continuing the steps of monitoring the operating parameter and lowering the target voltage;
• detecting said full charge of the battery;
• and
• initiating a timed sequence of continuing to charge at approximately said minimum value;
• and
• terminating application of said charging current.

A method of charging a battery utilizing a variable charge current supply comprising the steps of:

• applying a charging current to the battery from said charge current supply;
• sensing a variable parameter including battery voltage;
• analyzing the change in said variable parameter;
• establishing a target voltage for said battery;
• maintaining said battery voltage not greater than said target voltage;
• stepping up the charging current during the initial phase of charging in accordance with the change in said variable parameter to provide a stepped current profile until the charging current reaches a maximum value;
• applying said charging current until the battery is at full charge;
• monitoring change in an operating parameter of the battery during the application of the charging current;
• and
• lowering said target voltage in proportion to and to compensate for the change in the operating parameter being monitored.