Device and method for charging and controlling the charge of a battery

• US 8,570,001 B2
• Filed: 11/03/2005
• Issued: 10/29/2013
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: ams AG (Ams-Osram AG)
• Inventors: Haiplik, Holger, Bhler, Tobias
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US11/791,390
• Publication Number:
  US 20080252262A1
• Time in Patent Office: 2,917 Days
• Field of Search: 320/132, 320/152, 320157-159, 320162-164
• US Class Current: 320/163
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

An apparatus and a method for charging and for charge monitoring of a rechargeable battery. A charging circuit contains a rechargeable battery (B) and a charging device (L) for charging the rechargeable battery. A measurement device (M) is arranged in the charging circuit and contains a device for determining the rechargeable-battery current and the state of charge of the rechargeable battery. A control device (R) compares a value that is proportional to the rechargeable-battery current with a set value, and controls the charging device.

Claims

1. An apparatus for charging and for charge monitoring of a rechargeable battery, comprising:

a charging circuit which includes the rechargeable battery and a charging device for charging the rechargeable battery, and a measurement device, wherein the measurement device includes a device for determining the rechargeable-battery current and the state of charge of the rechargeable battery; and

a control device which compares a value that is proportional to the rechargeable-battery current with a set value, and controls the charging device by adjusting the rechargeable-battery current until a difference between the value that is proportional to the rechargeable-battery current and the set value disappears,

wherein the control device contains a regulator unit and a control signal converter connected to it,

wherein the control signal converter contains a digital-to-analog converter, and

wherein the digital-to-analog converter provides an analog control signal to control the charging device.

2. The apparatus as claimed in claim 1, wherein the rechargeable battery is based on lithium.

3. The apparatus as claimed in claim 1, wherein the measurement device contains a measured-value detection device and a downstream signal converter.

4. The apparatus as claimed in claim 3, wherein the signal converter contains a means for conversion of a voltage drop to a digital signal.

5. The apparatus as claimed in claim 4, wherein the means for conversion of the voltage drop to a digital signal contains a voltage/frequency converter or a sigma-delta converter.

6. The apparatus as claimed in claim 3, wherein the device for determining the rechargeable-battery current contains an evaluation device whose input side is connected to the signal converter.

7. The apparatus as claimed in claim 6, wherein the evaluation device contains:

an accumulating counter, having a value that corresponds to the state of charge of the rechargeable battery, and

an instantaneous current counter, having a value that is proportional to the instantaneous value of the rechargeable-battery current.

8. The apparatus as claimed in claim 1, in which the state of charge of the rechargeable battery is determined by means of the accumulating counter and a timebase.

9. The apparatus as claimed in claim 1, wherein the value of the instantaneous current counter and a reference value are applied to the input side of a comparator for the control device.

10. The apparatus as claimed in claim 1, wherein the charging device contains a transistor.

11. The apparatus as claimed in claim 10, in which the transistor is connected as an external component to an integrated circuit arrangement.

12. The apparatus as claimed in claim 1, wherein the charging device contains a resistor for setting a bias voltage.

13. The apparatus as claimed in claim 12, in which the resistor is connected as an external component to an integrated circuit arrangement.

14. The apparatus as claimed in claim 1, wherein the apparatus is in the form of an integrated circuit arrangement.

15. The apparatus as claimed in claim 1, wherein the measurement device contains an external component for measured-value detection.

16. The apparatus as claimed in claim 1, wherein the measurement device detects the magnitude and direction of the rechargeable-battery current.

17. A method for charging and for charge monitoring of a rechargeable battery, comprising the steps of:

detecting a measurement signal for the rechargeable-battery current;

producing a digital measurement signal from the measurement signal;

processing the digital measurement signal in order to form a first current value for determining the state of charge of the rechargeable battery;

processing the digital measurement signal in order to form a second current value;

comparing the second current value with a reference value, and determining a difference result;

producing a control manipulated variable from the difference result by a regulator;

converting the control manipulated variable into an analog control signal by a control signal converter comprising a digital-to-analog converter;

controlling a charging device for the rechargeable battery with the aid of the analog control signal; and

adjusting the rechargeable-battery current until the difference result between the second current value and the reference value disappears.

18. The method as claimed in claim 17, wherein the digital measurement signal is produced as an upward-counting signal or as a downward-counting signal.

19. The method as claimed in claim 17, wherein the digital measurement signal is added periodically recurrently using an instantaneous current counter and a timebase to form a value, in that this value is stored at the end of a period, and in that the value is then reset.

20. The method as claimed in claim 19, wherein the digital measurement signal is added continuously using an accumulating current counter and a timebase to form a current value which corresponds to the state of charge of the rechargeable battery.

21. The method as claimed in claim 20, wherein an instantaneous current and an accumulated current are derived from the gain of a signal converter, the time duration of the timebase and the value of a measurement resistor.

22. An apparatus for charging and for charge monitoring of a rechargeable battery, comprising:

a charging circuit which includes a rechargeable battery and a charging device for charging the rechargeable battery, and a measurement device, wherein the measurement device includes a device for determining the rechargeable-battery current and the state of charge of the rechargeable battery; and

a control device which compares a value that is proportional to the rechargeable-battery current with a set value, and controls the charging device by adjusting the rechargeable-battery current until a difference between the value that is proportional to the rechargeable-battery current and the set value disappears,

wherein the charging device contains a transistor,

wherein the charging device contains a resistor for setting a bias voltage, and

wherein the resistor is connected between a control terminal of the transistor and a first terminal of the transistor,

the first terminal of the transistor is connected to a charging source, and

the control device provides a control signal which is applied to the control terminal of the transistor.