Fast battery charger

In a battery charging system,

• (a) rechargeable battery means,
• (b) external terminals of opposite polarity for the rechargeable
• battery means,
• (c) external circuit means between said rechargeable battery means and said external terminals of opposite polarity, said external circuit means having essentially negligible ohmic resistance and connecting said external terminals of opposite polarity with said battery means,
• (d) load means at a load side of said external terminals, said external terminals having said load means connected there across at the load side of said external terminals such that said battery means supplies load current to said load means via said external circuit means with minimized ohmic loss at the battery side of said terminals, and
• (e) automatically operating programmed system means comprising
• (el) automatically operating processing means coupled with said external terminals for reading battery terminal voltage, and for increasing charging current to said battery means in successive steps to determine any load current being supplied to load means, and
• (e2) automatically operating control means operating to apply substantially maximum charging current to said battery means consistent with avoiding substantial detriment to the operating life thereof while additionally supplying any required load current.

In a battery charging system,

• (a) rechargeable battery means,
• (b) external terminals of opposite polarity for the rechargeable battery means,
• (c) external circuit means between said rechargeable battery means and said external terminals of opposite polarity, said external circuit means connecting said external terminals of opposite polarity with said battery means,
• (d) load means at a load side of said external terminals having said load means connected there across at the load side of said external terminals such that said battery means supplies load current to said load means via said external circuit means at the battery side of the said terminals, and
• (e) automatically operating programmed system means comprising automatically operating control means operating to apply substantially maximum charging current to said battery means consistent with avoiding substantial detriment to the operating life thereof,
• (f) said automatically operating control means having means for automatically identifying a sustained overcharge current rating for said battery means, and automatically supplying an overcharge current according to said sustained overcharge rating to said battery means when said battery means has attained an overcharge condition.

In a battery charging system,

• (a) rechargeable battery means,
• (b) external terminals of opposite polarity for the rechargeable battery means,
• (c) external circuit means between said rechargeable battery means and said external terminals of opposite polarity, said external circuit means connecting said external terminals of opposite polarity with said battery means,
• (d) load means at a load side of external terminals, said external terminals having said load means connected there across at the load side of said external terminals such that said battery means supplies load current to said load means via said external circuit means at the battery side of said terminals, and
• (e) automatically operating programmed system means comprising automatically operating control means operating to apply substantially maximum charging current to said battery means consistent with avoiding substantial detriment to the operating life thereof,
• (f) said automatically operating control means determining that battery temperature is within a given temperature range below a given upper limit temperature value, and then applying an excess overcharge current to said battery means which exceeds a sustained overcharge rating of the battery means while limiting the time of application of said excess overcharge current to a time sufficient to detect the charge condition of the battery means without substantial detriment to the operating life thereof.

The method of charging a battery pack comprising

• (a) applying a charge increment to a rechargeable battery means,
• (b) measuring a parameter sensitive to accumulation of charge by the battery means,
• (c) repeating steps (a) and (b) as necessary to effect a determination of any load current being supplied by the battery means, and
• (d) initiating a battery charging operation by supplying to the battery means a charging current taking account of any load current as determined by step (c) while enabling connections of minimum ohmic resistance between the battery means and the load.

Apparatus for charging a battery means, said apparatus comprising

• (a) operating means for automatically obtaining measures of ambient temperature and of battery temperature of the battery means,
• (b) said operating means automatically comparing the measures of the ambient temperature and said battery temperature, and when said measures show that said battery temperature is not substantially less than the ambient temperature, automatically applying current to the battery means of a substantial overcharge magnitude greater than a sustainable overcharge current, but of a limited duration such as to avoid substantial detriment to the useful life of the battery means even when in overcharged condition,
• (c) said operating means repeatedly automatically obtaining said measures of the battery temperature and sensing any change in said measures of the battery temperature which is distinctive of the overcharge condition of the battery means so as to automatically determine whether or not the battery means is in overcharge condition, and
• (d) means automatically applying a relatively high charge rate to said battery means while the battery means is not in the overcharge condition, and applying a relatively lower charge rate to said battery means when the battery means is in the overcharge condition.

A method of charging a battery means, said method comprising

• (a) insuring that battery temperature of the battery means is not substantially less than the ambient temperature, and that the battery means will exhibit a substantially greater increase in said battery temperature when subjected to current of a substantial overcharge magnitude when it is in an overcharged condition than when it is not in said overcharged condition,
• (b) automatically applying current to the battery means of said substantial overcharge magnitude, but of a limited duration such as to avoid substantial detriment to the useful life of the battery means even when in said overcharged condition,
• (c) automatically measuring said battery temperature and sensing any change of the battery temperature due to step (b) which is distinctive of said overcharged condition of the battery means so as to automatically determine whether or not the battery means is in said overcharged condition, and
• (d) automatically according to the result of step (c), applying a relatively high charge rate to said battery means while the battery means is not in said overcharged condition, and applying a relatively lower charge rate to said battery means when the battery means is in said overcharged condition.

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 and ambient temperature at successive times during the battery conditioning cycle, and
• (d) current control means for coupling with said rechargeable battery means for controlling a current flow rate to the rechargeable battery means during the battery conditioning cycle,
• (e) said computer means having output means coupled with said current control means for varying the current flow rate to said rechargeable battery means during the battery conditioning cycle as a function of the battery temperature as monitored by said computer means,
• (f) wherein said computer means senses a differential between the ambient temperature and the battery temperature to insure a 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 the battery conditioning cycle,
• (g) said computer means, including programming, and including connection means for obtaining a measure of battery voltage of the battery means from a battery voltage measuring means and automatically operating to provide respective successively increased values of the current flow rate to compensate for battery load, until such time as the battery voltage has stabilized, and maintaining the current flow rate which compensates for the battery load until the battery temperature has increased to a selected temperature value suited to fast charging operation.

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:

• (a) insuring that the battery means has a state such that its temperature will not increase at a substantial rate due to a higher ambient temperature, and that the battery means will exhibit a substantially greater increase in battery temperature when subjected to the overcharge current than when subjected to a charging current when it is not overcharged, by monitoring both absolute temperature of the battery means and relative temperature between the battery means and ambient temperature, and automatically maintaining the battery temperature of the battery means within absolute and relative limits,
• (b) automatically applying non-static, non-preset charging current at a charge at any stage of recharging to the battery means of a substantial magnitude, but measuring the battery temperature within a time interval after applying the charging current such as to avoid substantial detriment to useful life of the battery means prior to such measurement,
• (c) automatically sensing any change of the battery temperature which is distinctive of an overcharge condition of the battery means so as to automatically determine whether or not the battery means is in the overcharge condition, and
• (d) automatically according to the result of step (c), applying a relatively high charge rate as a function of the battery temperature to said battery means while the battery means is sensed not to be in the overcharge condition, and applying a relatively lower charge rate to said battery means when the battery means is in the overcharge condition, and in each case selecting the charge rate so as to avoid substantial detriment to the useful life of the battery means,
• (e) measuring the ambient temperature and, after the battery means has reached the overcharge condition, the overcharge current flow rate is automatically adjusted according to the differential between the battery temperature and the ambient temperature, so as to maintain the battery means substantially in a fully charged condition.

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

• (a) measuring battery voltage to produce a measured value and applying moderate non-static, non-present charging current at any stage of recharging to the battery means,
• (b) measuring battery temperature at successive times and determining whether the battery temperature is substantially outside a given temperature range before applying substantial charging current to the battery means, and if it is outside such temperature range,
• (c) sensing whether the applied moderate charging current has increased the battery voltage, and
• (d) increasing the charging current to the battery means a small increment where the battery voltage has not substantially increased within a given time interval.

A battery recharging system for recharging to and maintaining at maximum capacity a rechargeable battery 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 the battery temperature and the ambient temperature at least during the recharging period;
• output means included with the computer means for providing control signals to the current control means during the recharging period;
• overcharge detection means associated with the computer means for automatically sensing a change of the battery temperature which is distinctive of an overcharge condition of the battery means;
• and
• charge rate means associated with the computer means for automatically applying a relatively high charge rate of the recharging current, as a function of the battery temperature, to said battery means while the battery means is sensed not to be in the overcharge condition, and for applying a relatively lower charge rate of the recharging current to said battery means when the battery means is in the overcharge condition, and in each case selecting the charge rate so as to avoid substantial detriment to useful life of the battery means, said charge rate means dynamically and automatically adjusting the charging current as a function of the differential between the battery temperature and the ambient temperature to maintain the battery means in a substantially fully charged condition.

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

• rechargeable battery means for providing stored electric potential for use by a load;
• 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 the battery means for an overcharge condition;
• the computer means including input means for receiving repeated measurements of battery temperature and ambient temperature and output means for providing control signals to the current control means;
• overcharge detection means associated with the computer means for automatically sensing any change of the battery temperature which is distinctive of the overcharge condition of the battery means so as to automatically determine whether or not the battery means is in the overcharge condition;
• and
• charge rate means associated with the computer means for automatically and dynamically adjusting the recharging current to the battery means according to any ongoing differential between the battery temperature and the ambient temperature when the battery means has been sensed to have reached the overcharge condition, said charge rate means providing the battery means with a relatively low but variable rate of the recharging current to maintain the battery means substantially in a fully charged condition but to avoid substantial detriment to useful life of the battery means.

A method of charging a rechargeable battery means comprising:

• measuring the difference between battery temperature of the battery means and ambient temperature;
• applying a relatively low rate of charge current to the battery means if the battery temperature and the ambient temperature are not substantially close, to stabilize any temperature difference between the battery and ambient temperatures and prevent discharge of the battery means;
• measuring the battery temperature to detect if the battery temperature is within a given temperature range to determine if the battery means is within an optimal charging temperature range;
• applying a relatively moderate rate of charge current to the battery means if the battery temperature is outside the optimal charging temperature range, the relatively moderate rate dynamically varying as a function of the battery temperature to bring the battery temperature within the optimal charging temperature range;
• applying a relatively high rate of charge current to the battery means if the battery temperature is within the optimal charging temperature range, the relatively high rate dynamically varying as a function of the battery temperature, the rate of charge current always being selected so as to avoid substantial detriment to useful life of the battery means;
• measuring the difference between the battery temperature and the ambient temperature to sense any change of the battery temperature distinctive of an overcharge condition for the battery means;
• and applying the relatively low rate of charge current when the battery temperature is sensed to indicate an overcharge condition, the relatively low rate dynamically varying as a function of the battery temperature but always being selected so as to avoid substantial detriment to the useful life of the battery means.

A method for recharging a rechargeable battery means comprising:

• measuring battery and ambient temperature at successive times;
• stabilizing the battery means by causing any difference between the ambient temperature and the battery temperature to be substantially close;
• causing the battery temperature to be within a given optimal charging temperature range by measuring the battery temperature, comparing the battery temperature with the given optimal charging temperature range, measuring battery voltage, and dynamically applying current at a variable charge rate determined as a function of the battery temperature and the battery voltage, if the battery temperature is outside the optimal charging temperature range to bring the battery temperature within the optimal charging temperature range prior to recharging;
• dynamically applying a current to the battery at a relatively high variable charge rate once the battery temperature is within the optimal charging temperature range, the relatively high variable charge rate determined as a function of the difference between the battery temperature and the ambient temperature;
• continuing to apply the relatively high variable charge rate for fast recharging of the battery means while repetitively measuring the battery temperature to sense any battery temperature change which is distinctive of an overcharge condition of the battery means;
• and
• applying a relatively lower charge rate selected between a predetermined non-varying charge rate if the battery temperature exceeds the ambient temperature by a substantial amount, and a varying charge rate dynamically varying as a function of battery temperature if the battery temperature does not exceed the ambient temperature by a substantial amount, to maintain the battery means in a fully charged condition, but avoiding substantial detriment to useful life of the battery means.

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

• measuring battery and ambient temperatures at successive times;
• measuring battery voltage;
• preparing the battery for optimal charging by applying a relatively non-varying low charge rate to the battery if the ambient temperature and the battery temperature differ by a substantial amount, and by applying a relatively low but varying charge rate which dynamically various as a function of the battery temperature and the battery voltage if the battery temperature is outside a given optimal charging temperature range;
• charging the battery at a relatively fast charge rate which dynamically varies as a function of the battery temperature once the battery is prepared for optimal charging;
• continuously monitoring the battery temperature during application of the relatively fast charge rate to detect any increase of the battery temperature which indicates an overcharge condition of the battery;
• and
• immediately switching the relatively fast charge rate to the relatively low charge rate upon detection of the overcharge condition, the relatively low charge rate dynamically varying as a function of the battery temperature to maintain the battery fully charged without substantial detriment to useful, life of the battery.