Fast battery charger

A method of charging a battery means having a temperature characteristic when subject to overcharge current which exhibits a rising temperature as a function of overcharge current duration, said method comprising:

• measuring battery temperature;
• sensing any change in battery temperature which is distinctive of an overcharge condition of the battery means to automatically determine, without relying on measured battery voltaqe, whether or not the battery means is in the overcharge condition;
• measuring ambient temperature at successive times;
• applying a relatively high charge rate to said battery means while the battery means is sensed not to be in the overcharge condition, the relatively high charge rate being dynamically adjusted by successive relatively small incremental changes as a function of battery temperature;
• comparing battery and ambient temperatures;
• and
• applying a relatively lower charge rate to said battery means when the battery means is sensed to be in the overcharge condition, the relatively lower charge rate being dynamically adjusted by successive relatively small incremental changes as a function of the differential between battery temperature and ambient temperature to maintain the battery means substantially in a fully charged condition but to avoid substantial detriment to the useful life of the battery means.

A method of charging a battery means having a temperature characteristic when subject to overcharge current which exhibits a rising temperature as a function of overcharge current duration, said method comprising:

• measuring battery temperature at intervals;
• sensing any change in battery temperature which is distinctive of an overcharge condition of the battery means to automatically determine whether or not the battery means is in the overcharge condition without relying on measured battery voltage;
• measuring ambient temperature;
• comparing battery and ambient temperature;
• and
• applying a relatively lower charge rate to said battery means when the battery means is sensed to be in the overcharge condition, the relatively lower charge rate being dynamically adjusted by successively small incremental changes as a function of the differential between battery temperature and ambient temperature to maintain the battery means substantially in a fully charged condition but to avoid substantial detriment to the useful life of the battery means.

A method for fast charging of a rechargeable battery which maintains a battery in a fully charged capacity after charging and deters damage to the useful life of the battery during charging and after charging, comprising:

• determining when the battery is in an optimal condition for charging by measuring battery temperature, ambient temperature, and battery voltage to characterize current drain caused by battery load if any, and causing battery temperature to be in a given temperature range;
• presenting current to the battery at a relatively fast charge rate to quickly recharge the battery;
• monitoring battery temperature at closely repeated intervals to detect any increase of battery temperature which indicates an overcharged condition of the battery without relying on measured battery voltage;
• immediately converting the fast charge rate to a relatively lower charge rate upon detection of the overcharge condition;
• and
• monitoring battery temperature during overcharge condition and dynamically varying the lower charge rate as a function of battery temperature to provide an optimal charge rate which compensates for any battery load to maintain the battery in a fully charge condition while avoiding substantial detriment to the useful life of the battery.

In a battery conditioning system,

• (a) rechargeable battery means for supplying operating current during portable operation so as to become progressively discharged as a result.
• (b) battery conditioning system means for coupling with said rechargeable battery means for supplying current to said rechargeable battery means during a battery conditioning cycle, after a period of portable operation,
• (c) said battery conditioning system means comprising computer means having input means for receiving measures of battery temperature and ambient at successive time during such battery conditioning cycle, and
• (d) current control means for coupling with said rechargeable battery means for controlling the rate of current flow to the rechargeable battery means during a battery conditioning cycle,
• (e) said computer means having output means coupled with said current control means for varying the rate of current flow to said rechargeable battery means during a battery conditioning cycle as a function of battery temperature as monitored by said computer means without relying on measured battery voltage,
• (f) wherein said computer means senses a differential between ambient temperature and battery temperature to insure that battery temperature rise will be essentially a function of an overcharge condition of the battery means as substantial current flow rates are supplied to the battery means during a battery conditioning cycle, said computer means including programming, and including connection means for obtaining a measure of the voltage of the battery means from a battery voltage measuring means for characterizing current drain caused by battery load, if any, and automatically operating to provide respective successively increased values of current flow rate to compensate for battery load, until such time as battery voltage has stabilized, and maintaining a current flow rate which compensates for battery load until the battery temperature has increased to a elected temperature value suited to fast charging operation.

A battery recharging system for recharging and maintaining a rechargeable battery to maximum capacity comprising:

• rechargeable battery means for providing a stored electric potential;
• current control means for providing an adjustable recharging current to the battery means during a recharging period;
• computer means for controlling the current control means and monitoring temperature of the battery means and ambient temperature;
• input means included with the computer means for receiving successive measurements of battery temperature and ambient temperature at least during the recharging periods;
• output means included with the computer means for providing control signals to the current control means during the recharging;
• and
• overcharge detection means associated with the computer means for automatically sensing a change of battery temperature which is distinctive of an overcharge condition of the battery means by comparison in the computer means of the successive measurements of battery temperature and ambient temperature communicated to the computer means and without relying on measured battery voltage.

A method of charging a battery means having a temperature characteristic when subject to overcharge current which exhibits a rising temperature as a function of overcharge current duration, said method comprising:

• supplying charging current at a charge rate to the battery means;
• monitoring temperature of battery means at spaced intervals;
• monitoring ambient temperature at or near the battery means;
• determining an overcharge condition of the battery means by detecting a difference between battery temperature and ambient temperature of a magnitude distinctive of an overcharge condition of the battery means without relying on measured battery voltage;
• and
• supplying a relatively lower charge rate when an overcharge condition has been established;
• so that protection of the overcharge condition is made independent of any measurement of battery voltage, load, or battery current.

A method of charging a battery means which may have a load requiring current during charging operation, said method comprising:

• measuring battery temperature at spaced intervals;
• measuring ambient temperature;
• comparing battery and ambient temperature;
• and
• applying a relatively moderate charge rate of recharging current to the battery means, the charge rate being determined between at least two distinct levels as a function of the difference between battery temperature and ambient temperature but without relying on measured battery voltage;
• the relatively moderate charging current being dynamically adjusted by successive relatively small incremental changes as a function of a comparison of battery temperature, ambient temperature, and the rate of change of battery temperature.

A method of charging a battery means having a temperature characteristic when subject to overcharge current which exhibits a rising temperature as a function of overcharge current duration, the method comprising:

• monitoring temperature of the battery means at intervals;
• monitoring ambient temperature at or near the battery means;
• monitoring rate of change of the temperature of the battery means;
• comparing battery temperature and ambient temperature;
• and
• determining an overcharge condition of the battery means by detecting a rise in temperature of said battery means of a predetermined rate when said battery means temperature and said ambient temperature are within a predetermined range of one another when charging is initiated by application of charging current to the battery means but without relying on measured battery voltaqe so that protection of the battery means in an overcharged condition is made independent of any measurement of battery voltage, load, or battery current.

A method of charging a battery prior to its reaching an overcharge condition, which comprises:

• applying recharging current to the battery such that battery temperature may increase as a result;
• measuring battery temperature during application of such recharging current at time intervals not exceeding a time interval of the order of one minute;
• and
• incrementally adjusting the recharging current as a function of such battery temperature measurement so as to closely follow a schedule of maximum charge rates as a function of battery temperature which applies prior to the battery reaching the overcharge condition but without relying on measured battery voltage.

A method of charging a battery once it has reached an overcharge condition comprising:

• applying recharging current to the battery such that battery temperature may change as a result;
• measuring battery temperature during application of such recharging current at time intervals not exceeding a time interval of the order of one minute;
• and
• incrementally adjusting the recharging current as a function of such battery temperature measurements so as to closely follow a schedule of maximum charge rates as a function of battery temperature which applies after the overcharge condition has been reached but relying on measured battery voltage.

The method of charging a battery means which may have a load requiring current during charging operation, said method comprising:

• (a) measuring battery voltage to characterize current drain caused by battery load, if any, and applying moderate non-static, non-preset charging current at any stage of recharging to the battery means,
• (b) measuring battery temperature at successive times and determining whether batter temperature is substantially outside a given temperature range before applying substantial charge to the battery means, and if it is outside such temperature range,
• (c) sensing whether the applied current has increased battery voltage, and
• (d) increasing current to the battery means without relying on measured battery voltage by a small increment where battery voltage has not substantially increased within a given time interval.