Battery charge control circuit for a battery pack consisting of rechargeable battery elements

• US 20050156566A1
• Filed: 04/15/2003
• Published: 07/21/2005
• Est. Priority Date: 04/16/2002
• Status: Abandoned Application

• Current Assignee: SANYO Component Europe GmbH (United Kingdom) (Panasonic Holdings Corporation)
• Original Assignee: SANYO Component Europe GmbH (United Kingdom) (Panasonic Holdings Corporation)
• Inventors: Oefele, Karl, Thorsoe, Jan
• Application Number:
  US10/511,328
• Publication Number:
  US 20050156566A1
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection

Abstract

Disclosed is a battery control circuit for a battery pack consisting of rechargeable battery elements (9) which are arranged in respective parallel branches (3) battery voltage sources connected in parallel. State monitoring means are associated with each parallel branch (3) in order to monitor the state of the battery during a charging process of the battery pack and a respective switch (15), which can be controlled by the state monitoring means (11, 13, 17), is provided for the interruption or release of the charging current flow through the parallel branch (3) according to the state of the battery. The invention also relates to a discharge control circuit and a battery pack with an integrated battery charge control circuit/discharge control circuit.

Claims

1. (canceled)

11. (canceled)

16. A charge control circuit for a battery pack comprising rechargeable battery elements (9) which are arranged in respective parallel branches (3) of a parallel circuit of battery voltage sources, the charge control circuit comprising state monitoring means (11, 13, 17) for monitoring the battery state of battery elements (9), and the charge control circuit comprising switches (15), which can be controlled by the state monitoring means, for interrupting the current flow or releasing the current flow,

characterized in that each parallel branch (3) has associated state monitoring means (11, 13, 17), and in that a respective switch (15) is provided in each parallel branch (3), it being possible for said respective switch (15) to be controlled on the basis of the battery state, which is monitored by the state monitoring means (11, 13, 17), of the relevant parallel branch (3), in order to selectively block or release only this relevant parallel branch (3) for the current flow.

2. The charge control circuit as claimed in claim 16 characterized in that the state monitoring means (11, 13, 17) of a parallel branch (3) are set to switch the controllable switch (15) to the interrupted state when it detects a battery state “

parallel branch fully charged”

.

3. The charge control circuit as claimed in claim 16, characterized in that the parallel branch (3) are formed from identical groups of series-connected battery elements (9) which are connected in series with the respective controlled switch (15).

4. The charge control circuit as claimed in claim 16,

characterized in that the state monitoring means (11, 13, 17) comprise temperature sensors (11) for detecting the battery temperature in the individual parallel branches (3).

5. The charge control circuit as claimed in claim 4,

characterized in that the state monitoring means (11, 13, 17) of a relevant parallel branch (3) are set to switch the controllable switch (15) of the parallel branch (3) to the interrupted state when the battery temperature detected by the temperature sensor (11) in the parallel branch (3) exceeds a predetermined temperature value.

6. The charge control circuit as claimed in claim 16,

characterized in that the state monitoring means (11, 13, 17) comprise current measuring devices (13, 17) for detecting the current flowing through the individual parallel branch (3).

7. The charge control circuit as claimed in claim 6,

characterized in that the state monitoring means (11, 13, 17) are set to switch the controllable switch (15) of the relevant parallel branch to the interrupted state when the charge current flowing through the parallel branch (3) exceeds a predetermined current value for the duration of a predetermined time interval.

8. The charge control circuit as claimed in claim 16,

characterized in that the state monitoring means (11, 13, 17) are set to switch the controllable switch (15) of the respective parallel branch (3) to the interrupted state when the change in the battery temperature per unit time exceeds a comparison value depending on the respective charge current through the parallel branch (3).

9. The charge control circuit as claimed in claim 16,

characterized in that the state monitoring means (11, 13, 17) comprise a safety timer (13), and in that the state monitoring means (11, 13, 17) switch the controllable switch of the respective parallel branch to the interrupted state when a charge time interval, which is determined by the timer (13) on the basis of the charge current flowing through the relevant parallel branch (3), has expired.

10. The charge control circuit as claimed in claim 16,

characterized

in that the state monitoring means (11, 13, 17) comprise a respective microprocessor (13) per parallel branch (3) for the purpose of controlling the respective switch (15).

14. A battery control circuit, comprising the charge control circuit as claimed in claim 16 and a discharge control circuit combined therewith, wherein the discharge control circuit comprising state monitoring means (11, 13, 17) and switches (15), which can be controlled by the state monitoring means, for interrupting the current flow or releasing the current flow, each parallel branch having, in series with the battery voltage source (3) comprising one or more battery elements (9) represented by it a respective controllable switch (15) having an integrated diode (23), or one which is connected in parallel therewith, which is conductive in the discharge current flow direction,

characterized in that the state monitoring means (13) are set so as to switch the respective controllable switch (15) from a high-resistance state to a low-resistance state when a discharge current having a minimum current level flows through the diode (23).

15. A battery pack having the charge control circuit as claimed in claim 16 integrated therein.

19. A battery pack having the charge control circuit as claimed in claim 16, integrated therein and also having integrated therein a discharge control circuit which comprises state monitoring means (11, 13, 17) and switches (15), which can be controlled by the state monitoring means, for interrupting the current flow or releasing the current flow, each parallel branch having, in series with the battery voltage source (3) comprising one or more battery elements (9) represented by it, a respective controllable switch (15) having an integrated diode (23), or one which is connected in parallel therewith, which is conductive in the discharge current flow direction,

characterized in that the state monitoring means (13) are set so as to switch the respective controllable switch (15) from a high-resistance state to a low-resistance state when a discharge current having a minimum current level flows through the diode (23).

17. A discharge control circuit for a battery pack comprising rechargeable battery elements (9), which are arranged in respective parallel branches of a parallel circuit of battery voltage sources (3), the discharge control circuit comprising state monitoring means (11, 13, 17) and switches (15), which can be controlled by the state monitoring means, for interrupting the current flow or releasing the current flow, each parallel branch having, in series with the battery voltage source (3) comprising one or more battery elements (9) represented by it, a respective controllable switch (15) having an integrated diode (23), or one which is connected in parallel therewith, which is conductive in the discharge current flow direction,

characterized in that the state monitoring means (13) are set so as to switch the respective controllable switch (15) from a high-resistance state to a low-resistance state when a discharge current having a minimum current level flows through the diode (23).

12. The discharge control circuit as claimed in claim 17

characterized in that the controllable switches (15) are transistors, in particular field-effect transistors.

13. The discharge control circuit as claimed in claim 17,

characterized in that the state monitoring means comprise at least one microprocessor (13, 19), preferably at least in each case one microprocessor (13) for each parallel branch (3).

18. A battery pack having the discharge control circuit as claimed in claim 17 integrated therein.