Battery charger

• US 6,124,698 A
• Filed: 06/08/1999
• Issued: 09/26/2000
• Est. Priority Date: 06/09/1998
• Status: Expired due to Term

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Sakakibara, Kazuyuki
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/327,562
• Time in Patent Office: 476 Days
• Field of Search: 320/110, 320/119, 320/125, 320/132, 320/137, 320/150, 320/153, 320/160
• US Class Current: 320/110
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A battery charger determines the completion of battery charge based on a battery temperature and a temperature rise value. In determination, if the battery temperature and the battery rise temperature belong to a region in the map, which tends to occur at the beginning of a final charging period (`In` in a step S334), a low count value "1" is added to a counter (in a step S336). If they belong to a region which tends to occur at the end of the final charging period (`In` in a step S340), a high count value "3" is added to the counter (in a step S340). If the sum of the count values exceeds a set value, completion of battery charge is determined (`High` in a step S348). That is, if temperature rise is large and the temperature rise remains large even with the charging current value being lowered, then a high count value is added to the counter. If temperature rise is large but the temperature rise does not increase very much with the charging current value being lowered, then a low count value is added to the counter. Thus, the battery can be charged to a target capacity without influences of the battery residual capacity, temperature and the like.

Claims

1. A battery charger comprising;

a storage device storing at least two types of maps, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, in accordance with a temperature of the battery charger;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery charger temperature detecting means for detecting the temperature of said battery charger;

allowable current value retrieving means for retrieving a map corresponding to the battery charger temperature, from the battery charger temperature detected by said battery charger temperature detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

2. The battery charger according to claim 1, wherein the map used when the battery charger temperature is high and corresponding to said battery charger temperature, is set so as not to carry high charging current.

3. A battery charger comprising;

a storage device storing a map in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current retrieving means;

first charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected is high by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map of said storage device;

second charge completion determining means for determining completion of battery charge if the temperature rise value outputted from said temperature rise value outputting means exceeds a preset temperature rise value; and

charge completing means for completing the battery charge based on determinations as the completion of the battery charge by said first charge completion determining means and said second charge completion determining means.

4. A battery charger comprising;

a storage device storing a map in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

first charge completion determining means for determining completion of battery charge based on whether frequency is high with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map of said storage device;

second charge completion determining means for determining completion of battery charge if the temperature value outputted from said temperature detecting means exceeds a preset temperature value; and

charge completing means for completing the battery charge based on determinations by said first charge completion determining means and said second charge completion determining means.

5. A battery charger comprising;

a storage device storing a map in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

voltage detecting means for detecting battery voltage;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current retrieving means;

first charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map of said storage device, is high;

second charge completion determining means for determining completion of battery charge if a decrease value of the battery voltage outputted from said voltage detecting means exceeds a preset decrease value; and

charge completing means for completing the battery charge based on determinations by said first charge completion determining means and by said second charge completion determining means.

6. A battery charger comprising;

a storage device storing a map in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current retrieving means;

first charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map of said storage device, is high;

second charge completion determining means for integrating charging current quantity for said battery and for determining completion of battery charge if an integral value exceeds a preset integral value; and

charge completing means for completing the battery charge based on determinations by said first charge completion determining means and by said second charge completion determining means.

7. A battery charger comprising;

a storage device storing a map in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current retrieving means;

charge completion determining means for determining completion of battery charge based on whether the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region, which tends to occur in a final charging period in the map of said storage device, for adding a low count value to a count if the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region, which tends to occur at a start of the final charging period in the map, for adding a high count value to the count if the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region, which tends to occur at an end of the final charging period in the map, and for determining the completion of the battery charge if a sum of count values exceeds a set value; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said first charge completion determining means and by said second charge completion determining means.

8. A battery charger capable of charging a battery of a first type and a battery of a second type comprising:

a storage device for storing a map in which an allowable current value, with which the battery of the first type can be charged while a temperature rise of the battery of the first type is being suppressed, is mapped based on a battery temperature and a battery temperature rise value;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery type detecting means for detecting whether a battery is the first type or the second type;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, the allowable value retrieving means retrieving said map and obtaining and outputting the allowable current value if the battery of first type is detected by said battery type detecting means, the allowable value retrieving means correcting at least one of the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, retrieving said map, obtaining the allowable current value and correcting and outputting the obtained allowable current value; and

charging means for charging the battery with the allowable current value outputted by said allowable current retrieving means.

10. The battery charger according to claim 8 wherein

said battery of the first type is a nickel metal hydride battery and the battery of the second type is a nickel cadmium battery;

and

said allowable current value retrieving means obtains the allowable current value by correcting the temperature rise value to a positive side and retrieving said map, corrects the obtained allowable current value to a positive side and outputs the corrected allowable current value.

12. The battery charger according to claim 8, wherein

said battery of the first type is a nickel cadmium battery and the battery of the second type is a nickel metal hydride battery;

and

said allowable current value retrieving means obtains the allowable current value by correcting the temperature rise value to a negative side and retrieving said map, corrects the obtained allowable current value to a negative side and outputs the corrected allowable current value.

9. A battery charger capable of charging a battery of a first type and a battery of a second type comprising:

a storage device for storing a map in which an allowable current value, with which the battery of the first type can be charged while a temperature rise of the battery of the first type is being suppressed, is mapped based on a battery temperature and a battery temperature rise value;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery type detecting means for detecting whether a battery is the first type or the second type;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, the allowable value retrieving means retrieving said map and obtaining and outputting the allowable current value if the battery of first type is detected by said battery type detecting means, the allowable value retrieving means correcting at least one of the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, retrieving said map, obtaining the allowable current value and correcting and outputting the obtained allowable current value;

charging means for charging the battery with the allowable current value obtained by said allowable current retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map of said storage means, is high, the charge completion determining means directly retrieving said map if the battery of the first type is detected by said battery type detecting means, the charge completion determining means retrieving said map after correcting at least one of the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

11. The battery charger according to claim 9, wherein

said battery of the first type is a nickel metal hydride battery and the battery of the second type is a nickel cadmium battery;

and

said allowable current value retrieving means obtains the allowable current value by correcting the temperature rise value to a positive side and retrieving said map, corrects the obtained allowable current value to a positive side and outputs the corrected allowable current value.

13. The battery charger according to claim 9, wherein

said battery of the first type is a nickel cadmium battery and the battery of the second type is a nickel metal hydride battery;

and

said allowable current value retrieving means obtains the allowable current value by correcting the temperature rise value to a negative side and retrieving said map, corrects the obtained allowable current value to a negative side and outputs the corrected allowable current value.

14. A battery charger capable of charging batteries of different types comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, for every battery type;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery type detecting means for detecting a battery type;

allowable current value retrieving means for retrieving the map for the battery of the detected battery type of said storage device, from the battery type detected by said battery type detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

15. A battery charger capable of charging batteries of different types comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high, for every battery type;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery type detecting means for detecting a battery type;

allowable current value retrieving means for retrieving the map for the battery of the detected battery type of said storage device, from the battery type detected by said battery type detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map for the battery of the detected battery type, is high; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

16. A battery charger capable of charging batteries of different voltages comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, for every battery voltage;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery voltage detecting means for detecting a battery voltage;

allowable current value retrieving means for retrieving the map for the detected battery voltage, from the battery voltage detected by said battery voltage detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

17. A battery charger capable of charging batteries of different voltages comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, for every battery voltage;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery voltage detecting means for detecting a battery voltage;

allowable current value retrieving means for retrieving the map for the detected battery voltage, from the battery voltage detected by said battery voltage detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map for the battery voltage, is high; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

18. A battery charger for charging a current, capable of outputting a residual battery capacity comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, for every residual battery capacity;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

battery capacity receiving means for receiving the residual battery capacity;

allowable current value retrieving means for retrieving the map for the received residual battery capacity of said storage device, from the battery residual capacity received by said battery capacity receiving means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

19. A battery charger for charging a battery, capable of outputting a residual battery capacity comprising;

a storage device storing a map, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high, for every residual battery capacity;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

residual battery capacity receiving means for receiving the residual battery capacity;

allowable current value retrieving means for retrieving the map for the residual battery capacity detected battery voltage, from the residual battery capacity received by said battery capacity receiving means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map for the residual battery capacity, is high; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

20. A battery charger comprising;

a storage device storing at least two types of maps, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, in accordance with an environmental temperature;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

environmental temperature detecting means for detecting the environmental temperature;

allowable current value retrieving means for retrieving a map for the environmental temperature, from the environmental temperature detected by said environmental temperature detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

21. A battery charger comprising;

a storage device storing at least two types of maps, in which an allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high, in accordance with an environmental temperature;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

environmental temperature detecting means for detecting the environmental temperature;

allowable current value retrieving means for retrieving the map for the environmental temperature, from the environmental temperature detected by said environmental temperature detecting means, the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map for the environmental temperature of said storage device, is high; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

22. A battery charger comprising;

a storage device storing maps in which the allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value, said maps including a first map for setting a relatively high allowable current value and a second map for setting a relatively low allowable current value;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

map selecting means for selecting one of the first map and the second map of said storage device;

allowable current value retrieving means for retrieving the map selected by said map selecting means, from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value; and

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means.

23. A battery charger comprising;

a storage device storing maps in which the allowable current value, with which a battery can be charged while a temperature rise of the battery is being suppressed, is mapped based on a battery temperature value and a battery temperature rise value and in which the allowable current value is set low if the temperature value is high and the allowable current value is set low if the temperature rise value is high, said maps including a first map in which a target current capacity is relatively high and a second map in which the target current capacity is relatively low;

temperature detecting means for detecting a current battery temperature;

temperature rise value outputting means for obtaining the temperature rise value from the temperature detected by said temperature detecting means;

map selecting means for selecting one of the first map and the second map of said storage device;

allowable current value retrieving means for retrieving the map selected by said map selecting means, from the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means, and for obtaining said allowable current value;

charging means for charging the battery with the allowable current value retrieved by said allowable current value retrieving means;

charge completion determining means for determining completion of battery charge based on whether frequency, with which the temperature detected by said temperature detecting means and the temperature rise value outputted from said temperature rise value outputting means belong to a region indicating a final charging period in the map selected by said map selecting means, is high; and

charge completing means for completing the battery charge based on determination as the completion of the battery charge by said charge completion determining means.

24. A battery charger for conducting one of auxiliary charge and trickle charge after completing battery charge, characterized by comprising:

a storage device storing a map in which an allowable current value, with which a battery can be charged in a pulse-like manner while a battery temperature is being suppressed, and a pulse interval are mapped based on a battery temperature and a battery temperature decrease value;

temperature detecting means for detecting a current battery temperature;

temperature decrease value outputting means for obtaining the temperature decrease value from the temperature detected by said temperature detecting means;

allowable current value retrieving means for retrieving the map of said storage device from the temperature detected by said temperature detecting means and the temperature decrease value outputted from said temperature decrease value outputting means, and for obtaining said allowable current value and said pulse interval; and

charging means for charging the battery with the allowable current value the pulse interval detected by said allowable current value retrieving means.

25. The battery charger according to claim 24, wherein the map of said storage device is set such that if the battery temperature is high and the temperature decrease is small, the allowable current value is high and the pulse interval is long and that if the battery temperature is low and the temperature decrease is large, the allowable current value is low and the pulse interval is short.