Battery pack

This application claims priority to U.S. Provisional No. 61/490,542, titled “BATTERY PACK” filed May 26, 2011, which is hereby incorporated by reference in its entirety.

1. Field

The disclosed technology relates to a battery pack, and a terminal configuration thereof.

2. Description of the Related Technology

Rechargeable secondary batteries are used as portable power sources for portable electronic equipment such as cellular phones, notebook computers, camcorders, personal digital assistants (PDA), and home appliances such as a vacuum cleaner. In a typical home vacuum cleaner, a motor of the vacuum cleaner is driven using AC power. However, in order to use the home vacuum cleaner in a space without AC power connected, a secondary battery as a separate power source is provided. The secondary battery has capabilities according to the application, and in many applications, high capacity voltage of approximately 100 V or higher is required.

An aspect of the present invention provides a battery pack for achieving high-efficiency charging and high-power discharging.

Another inventive aspect is a battery pack, including a plurality of positive and negative battery terminals, configured to connect to a plurality of battery units. The battery pack also includes a plurality of positive charge terminals, each connected to one of the positive battery terminals, and a plurality of positive discharge terminals, each connected to one of the positive battery terminals. The battery pack also includes a plurality of negative charge terminals, each connected to one of the negative battery terminals, a plurality of negative discharge terminals, each connected to one of the negative battery terminals, and a plurality of discharge control switches connected to the positive and negative discharge terminals, and a control unit, configured to control the state of the switches so as to selectively series connect the battery units.

Another inventive aspect is a battery pack, including a plurality of battery units, each configured to be individually charged by an external charger and to be discharged by providing power to an external load, a plurality of switches connected to the battery units, and a control unit configured to control the switches so that if the battery pack is not being charged, the battery units are serially connected.

Another inventive aspect is a battery pack, including a plurality of battery units, each battery unit having a positive and a negative terminal, and a control unit configured to provide a first configuration for discharging the battery units, where the battery units are connected, and to provide a second configuration for charging the battery units, where the battery units are not connected.

FIG. 1A is a block diagram illustrating a battery pack and a charger in a discharge standby mode according to an embodiment of the present invention;

FIG. 1B is a circuit diagram corresponding to FIG. 1A ;

FIG. 1C is an equivalent circuit diagram of a battery pack for the battery pack discharge standby mode of FIG. 1A ;

FIG. 2A is a circuit diagram illustrating a battery pack and a charger in a charge standby mode according to an embodiment of the present invention;

FIG. 2B is an equivalent circuit diagram of a battery pack for the battery pack charge standby mode of FIG. 2A ;

FIG. 3A is a circuit diagram illustrating a battery pack and a charger in a discharge mode according to an embodiment of the present invention;

FIG. 3B is an equivalent circuit diagram of a battery pack for the battery pack discharge mode of FIG. 3A ; and

FIG. 4 is a flowchart illustrating charge/discharge operation algorithm of a battery pack according to an embodiment of the present invention.

Example embodiments will now be described more fully with reference to the accompanying drawings; however, the inventive features and aspects may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

FIG. 1A is a block diagram illustrating a battery pack 100 and a charger 200 , and FIG. 1B is a circuit diagram corresponding to FIG. 1A . Referring to FIGS. 1A and 1B , the battery pack 100 includes a battery module 110 , a battery management unit 120 , and a control unit 130 , such as a microcontroller.

The battery module 110 includes a plurality of battery units. For example, as shown in FIG. 1A , the battery module 110 may include first to third battery units 111 , 112 and 113 . The battery module 110 is described with the battery module 110 including three battery units, but other embodiments have different numbers of battery units.

Each of the battery units 111 , 112 and 113 includes a plurality of battery cells. The plurality of battery cells included in each of the battery units 111 , 112 and 113 are connected to each other in series or in parallel.

In addition, the battery units 111 , 112 and 113 include terminals, respectively. For example, as shown in FIG. 1A , the first battery unit 111 includes a first positive terminal B 1 + and a first negative terminal B 1 −. In addition, the second battery unit 112 includes a second positive terminal B 2 + and a second negative terminal B 2 −. In addition, the third battery unit 113 includes a third positive terminal B 3 + and a third negative terminal B 3 −.

The battery management unit 120 includes first to third single battery management units 121 , 122 and 123 , a charge terminal unit 124 , and a discharge terminal unit 125 .

The first single battery management unit 121 includes a first charge/discharge switch 121 a , a first fuse unit 121 b , a first switch control unit 121 c , and a first charge/discharge terminal unit 121 d . The first charge/discharge switch 121 a may consist of a charge switch and a discharge switch. The charge switch and the discharge switch may be electrically connected between the first positive terminal B 1 + of the first battery unit 111 and the first positive battery terminal B 1 + of the first single battery management unit 121 . The first charge/discharge switch 121 a allows the first battery unit 111 to be charged and discharged and serves as a primary protective circuit device when over-charge or over-discharge occurs.

The first fuse unit 121 b may consist of a first fuse, a first heat resistor, and a first fuse switch. In such a case, the first fuse unit 121 b may serve as a secondary protective circuit device when the first charge/discharge switch 121 a is damaged, malfunctions, or is otherwise insufficient. In this embodiment, the first fuse switch is controlled by the first switch control unit 121 c.

The first switch control unit 121 c controls the switching operation of the first charge/discharge switch 121 a according to charge/discharge mode, thereby controlling charging and discharging of the first battery unit 111 . In addition, the first switch control unit 121 c detects one or more voltages of the first battery unit 111 and performs over-charge/over-discharge protection and voltage balancing of the first battery unit 111 based on the detected voltages.

The first charge/discharge terminal unit 121 d includes a first positive charge terminal CP 1 + and a first positive discharge terminal DP 1 + connected to the first fuse unit 121 b , and a first negative charge terminal CP 1 − and a first negative discharge terminal DP 1 − connected to the first negative terminal B 1 − of the first battery unit 111 through the first negative battery terminal B 1 − of the first single battery management unit 121 .

In this embodiment, the first positive terminal B 1 + of the first battery unit 111 is connected to the first positive charge terminal CP 1 + and the first positive discharge terminal DP 1 + through the first charge/discharge switch 121 a and the first fuse unit 121 b . In addition, the first negative terminal B 1 − of the first battery unit 111 is connected to the first negative charge terminal CP 1 − and the first negative discharge terminal DP 1 − through a current sensor 121 e for sensing the current of the first battery unit 111 . In some embodiments, the first negative terminal B 1 − of the first battery unit 111 is directly connected to the first negative charge terminal CP 1 − and the first negative discharge terminal DP 1 −.

The second single battery management unit 122 includes a second charge/discharge switch 122 a , a fuse 122 b , a second switch control unit 122 c , and a second charge/discharge terminal unit 122 d . The second charge/discharge switch 122 a may consist of a charge switch and a discharge switch. The charge switch and the discharge switch may be electrically connected between the second positive terminal B 2 + of the second battery unit 112 and the second positive battery terminal B 2 + of the second single battery management unit 122 . The second charge/discharge switch 122 a allows the second battery unit 112 to be charged and discharged and serves as a primary protective circuit device when over-charge or over-discharge occurs.

The second fuse unit 122 b may consist of a second fuse, a second heat resistor, and a second fuse switch. In such a case, the second fuse unit 122 b may serve as a secondary protective circuit device when the second charge/discharge switch 122 a is damaged, malfunctions, or is otherwise insufficient. In this embodiment, the second fuse switch is controlled by the second switch control unit 122 c.

The second switch control unit 122 c controls the switching operation of the second charge/discharge switch 122 a according to charge/discharge mode, thereby controlling charging and discharging of the second battery unit 112 . In addition, the second switch control unit 122 c detects one or more voltages of the second battery unit 112 and performs over-charge/over-discharge protection and voltage balancing of the second battery unit 112 based on the detected voltages.

The second charge/discharge terminal unit 122 d includes a second positive charge terminal CP 2 + and a second positive discharge terminal DP 2 + connected to the second fuse unit 122 b , and a second negative charge terminal CP 2 − and a second negative discharge terminal DP 2 − connected to the second negative terminal B 2 − of the second battery unit 112 through the second negative battery terminal B 2 − of the second single battery management unit 122 .

In this embodiment, the second positive terminal B 2 + of the second battery unit 112 is connected to the second positive charge terminal CP 2 + and the second positive discharge terminal DP 2 + through the second charge/discharge switch 122 a and the second fuse unit 122 b . In addition, the second negative terminal B 2 − of the second battery unit 112 is connected to the second negative charge terminal CP 2 − and the second negative discharge terminal DP 2 − through a current sensor 122 e for sensing the current of the second battery unit 112 . In some embodiments, the second negative terminal B 2 − of the second battery unit 112 is directly connected to the second negative charge terminal CP 2 − and the second negative discharge terminal DP 2 −.

The third single battery management unit 123 includes a third charge/discharge switch 123 a , a fuse 123 b , a third switch control unit 123 c , and a third charge/discharge terminal unit 123 d . The third charge/discharge switch 123 a may consist of a charge switch and a discharge switch. The charge switch and the discharge switch may be electrically connected between the third positive terminal B 3 + of the third battery unit 113 and the third positive battery terminal B 3 + of the first single battery management unit 121 . The third charge/discharge switch 123 a allows the third battery unit 113 to be charged and discharged and serves as a primary protective circuit device when over-charge or over-discharge occurs.

The third fuse unit 123 b may consist of a third fuse, a third heat resistor, and a third fuse switch. In such a case, the third fuse unit 123 b may serve as a secondary protective circuit device when the third charge/discharge switch 123 a is damaged, malfunctions, or is otherwise insufficient. In this embodiment, the third fuse switch is controlled by the third switch control unit 123 c.

The third switch control unit 123 c controls the switching operation of the third charge/discharge switch 123 a according to charge/discharge mode, thereby controlling charging and discharging of the third battery unit 113 . In addition, the third switch control unit 123 c detects one or more voltages of the third battery unit 113 and performs over-charge/over-discharge protection and voltage balancing of the third battery unit 113 based on the detected voltages.

The third charge/discharge terminal unit 123 d includes a third positive charge terminal CP 3 and a third positive discharge terminal DP 3 + connected to the second fuse unit 123 b , and a third negative charge terminal CP 3 − and a third negative discharge terminal DP 3 − connected to the third negative terminal B 3 − of third battery unit 113 through the third negative battery terminal B 3 − of the first single battery management unit 123 .

In this embodiment, the third positive terminal B 3 + of the third battery unit 113 is connected to the third positive charge terminal CP 3 + and the third positive discharge terminal DP 3 + through the third charge/discharge switch 123 a and the third fuse unit 123 b . In addition, the third negative terminal B 3 − of the third battery unit 113 is connected to the third negative charge terminal CP 3 − and the third negative discharge terminal DP 3 − through a current sensor 123 e for sensing the current of the third battery unit 113 . In some embodiments, the third negative terminal B 3 − of the third battery unit 113 is directly connected to the third negative charge terminal CP 3 − and the third negative discharge terminal DP 3 −.

The charge terminal unit 124 includes first to third positive charge terminals CP 1 +, CP 2 + and CP 3 + and first to third negative charge terminals CP 1 −, CP 2 − and CP 3 −. The charge terminal unit 124 has charge terminals for the first to third charge/discharge terminal unit 121 d , 122 d , 123 d in a single physical unit.

Accordingly, the first positive charge terminal CP 1 +, the second positive charge terminal CP 2 + and the third positive charge terminal CP 3 + of the charge terminal unit 124 are electrically connected in one-to-one correspondence to the first positive charge terminal CP 1 +, the second positive charge terminal CP 2 + and the third positive charge terminal CP 3 + respectively included in the first to third charge/discharge terminal units 121 d , 122 d , 123 d . In addition, the first negative charge terminal CP 1 −, the second negative charge terminal CP 2 − and the third negative charge terminal CP 3 − of the charge terminal unit 124 are electrically connected in one-to-one correspondence to the first negative charge terminal CP 1 −, the second negative charge terminal CP 2 − and the third negative charge terminal CP 3 − respectively included in the first to third charge/discharge terminal units 121 d , 122 d , 123 d.

The discharge terminal unit 125 includes first to third positive discharge terminals DP 1 +, DP 2 + and DP 3 + and first to third negative discharge terminals DP 1 −, DP 2 − and DP 3 −. The discharge terminal unit 125 has discharge terminals for the first to third charge/discharge terminal units 121 d , 122 d , 123 d in a single physical unit. In some embodiments, the charge terminal unit is spaced apart from the discharge terminal unit.

The positive and negative charge terminals of the charge terminal unit 124 are spaced apart from one another and the positive and negative discharge terminals are spaced apart from one another. In addition, the positive and negative charge terminals are spaced apart from the positive and negative discharge terminals by a distance greater than the spacing of the positive and negative charge terminals and greater than the spacing of the positive and negative discharge terminals.

The first positive discharge terminal DP 1 +, the second positive discharge terminal DP 2 +, and the third positive discharge terminal DP 3 + of the discharge terminal unit 125 are electrically connected in one-to-one correspondence to the first positive discharge terminal DP 1 +, the second positive discharge terminal DP 2 + and the third positive discharge terminal DP 3 + respectively included in the first to third charge/discharge terminal units 121 d , 122 d , 123 d . In addition, the first negative discharge terminal DP 1 −, the second negative discharge terminal DP 2 − and the third negative discharge terminal DP 3 − of the discharge terminal unit 125 are electrically connected in one-to-one correspondence to the first negative discharge terminal DP 1 −, the second negative discharge terminal DP 2 − and the third negative discharge terminal DP 3 − respectively included in the first to third charge/discharge terminal units 121 d , 122 d , 123 d.

The connection control unit 130 has a controller 135 , which determines whether the charger 200 is connected to an external power supply if the battery pack 100 and the charger 200 are connected to each other, and determines whether or not to maintain a series connection of the first to third battery units 111 , 112 and 113 .

The controller 135 includes charge recognizing units TB 1 and TB 2 , a plurality of discharge control terminals, and first and second discharge control switches SW 1 and SW 2 . If the battery pack 100 is connected to the charger 200 , the charge recognizing units TB 1 and TB 2 of the connection control unit 130 may be connected to charge recognizing units TB 1 and TB 2 of the charger 200 . The charge recognizing units TB 1 and TB 2 of the connection control unit 130 include a positive charge recognizing unit TB 1 and a negative charge recognizing unit TB 2 . Likewise, the charge recognizing units TB 1 and TB 2 of the charger 200 include a positive charge recognizing unit TB 1 and a negative charge recognizing unit TB 2 . If the battery pack 100 is connected to the charger 200 , the positive charge recognizing unit TB 1 of the connection control unit 130 is connected to the positive charge recognizing unit TB 1 of the charger 200 , and the negative charge recognizing unit TB 2 of the connection control unit 130 is connected to the negative charge recognizing unit TB 2 of the charger 200 .

The connection control unit 130 detects a voltage of the charger 200 through the charge recognizing units TB 1 and TB 2 of the connection control unit 130 and controls switching operations of the first and second discharge control switches SW 1 and SW 2 according to whether a level of the detected voltage is shifted from ‘high’ to ‘low’ or vice versa, or whether a low level is maintained.

The discharge control terminals may consist of first to third positive discharge control terminals and first to third negative discharge control terminals. For example, the first to third positive discharge control terminals and the first to third negative discharge control terminals are respectively electrically connected in one-to-one correspondence to the first to third positive discharge terminals DP 1 +, DP 2 + and DP 3 + and the first to third negative discharge terminals DP 1 −, DP 2 − and DP 3 − of the discharge terminal unit 125 . The first positive discharge control terminal DP 1 + is electrically connected to a pack positive terminal P 1 +, and the third negative discharge control terminal DP 3 − is electrically connected to a pack negative terminal P 3 −. The pack positive terminal P 1 + and the pack negative terminal P 3 − are terminals which are connected to an external load when the battery pack 100 is discharged.

The first and second discharge control switches SW 1 and SW 2 are electrically connected between discharge control terminals. For example, as shown in the embodiment of FIGS. 1A and 1B , the first discharge control switch SW 1 may be electrically connected between the first negative discharge control terminal DP 1 − and the second positive discharge control terminal DP 2 +. In addition, the second discharge control switch SW 2 may be electrically connected between the second negative discharge control terminal DP 2 − and the third positive discharge control terminal DP 3 +. Further, diodes D 1 and D 2 may be connected between the first negative discharge control terminal DP 1 − and the first discharge control switch SW 1 and between the second negative discharge control terminal DP 2 − and the second discharge control switch SW 2 .

The diodes D 1 and D 2 allow the first to third battery units to be connected so as to output a discharge current when a battery pack is discharged. When a battery pack is charged, the diodes D 1 and D 2 prevent current path connections between the first to third battery units. As shown in FIG. 1A , the connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 to electrically connect the first negative discharge control terminal DP 1 − and the second positive discharge control terminal DP 2 + and the second negative discharge control terminal DP 2 − and the third positive discharge control terminal DP 3 + when the battery pack 100 is in a discharge standby mode, that is, in a natural discharge state. If the first negative discharge control terminal DP 1 − and the second positive discharge control terminal DP 2 + are connected to each other, the first negative terminal B 1 − of the first battery unit 111 and the second positive terminal B 2 + of the second battery unit 112 are connected to each other. If the second negative discharge control terminal DP 2 − and the third positive discharge control terminal DP 3 + are connected to each other, the second negative terminal B 2 − of the second battery unit 112 and the third positive terminal B 3 + of the third battery unit 113 are connected, thereby establishing series connections between the first to third battery units 111 , 112 and 113 . The connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 not only in a discharge standby mode but also in a discharge mode, thereby establishing series connections between the first to third battery units 111 , 112 and 113 .

The charger 200 includes a plurality of output terminals and charge recognizing units TB 1 and TB 2 . The output terminals of the charger 200 are configured to correspond to the first to third positive charge terminal CP 1 +, CP 2 +, CP 3 + and the first to third negative charge terminal CP 1 −, CP 2 −, CP 3 − of the charge terminal unit 124 in one-to-one relationship. For example, the plurality of output terminals of the charger 200 consist of first to third positive output terminals and first to third negative output terminals. When the battery pack 100 is connected to the charger 200 , the first to third positive output terminals of the charger 200 are connected to the positive charge recognizing unit TB 1 of the charger 200 , and the first to third negative output terminals of the charger 200 are connected to the negative charge recognizing unit TB 2 of the charger 200 . Therefore, when the battery pack 100 is connected to the charger 200 , for example, high-level potentials may be formed in the positive charge recognizing unit TB 1 and the negative charge recognizing unit TB 2 .

Functionality of the battery pack 100 according to an embodiment is described with reference to the accompanying drawings.

FIG. 1C is an equivalent circuit diagram of a battery pack for the battery pack discharge standby mode of FIG. 1A . FIG. 2A is a circuit diagram illustrating a battery pack and a charger in a charge standby mode according to an embodiment, and FIG. 2B is an equivalent circuit diagram of a battery pack for the battery pack charge standby mode of FIG. 2A . FIG. 3A is a circuit diagram illustrating a battery pack and a charger in a discharge mode according to an embodiment, and FIG. 3B is an equivalent circuit diagram of a battery pack for the battery pack discharge mode of FIG. 3A . FIG. 4 is a flowchart illustrating charge/discharge algorithm of a battery pack according to an embodiment.

1. Discharge Standby Mode

In order to recognize the current mode of the battery pack 100 , the connection control unit 130 continuously detects voltages of the battery pack 100 through the charge recognizing units TB 1 and TB 2 (S 410 ).

The connection control unit 130 determines whether a level of the detected voltage is high (S 420 A) or low (S 420 B). If the level of the detected voltage is low (S 420 B), the connection control unit 130 recognizes that the battery pack 100 is in a discharge standby mode (S 460 ).

In this case, the connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 to connect the first to third battery units 111 , 112 and 113 in series (S 470 ). The connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 to maintain the first to third battery units 111 , 112 and 113 to be connected to each other in series when the battery pack 100 is not charged by the charger 200 or is not discharged by being connected to an external load, that is, in a natural discharge state, which may be represented by an equivalent circuit shown in FIG. 1B .

2. Charge Mode

When output terminals of the charger 200 connected to an external power supply are connected to the charge terminal unit 124 of the battery pack 100 , the level of the voltage detected through the charge recognizing units TB 1 and TB 2 of the connection control unit 130 is shifted from ‘low’ to ‘high’ (S 420 A). The connection control unit 130 recognizes a mode of the battery pack 100 as a charge mode (S 430 ). Accordingly, the connection control unit 130 turns off the first and second discharge control switches SW 1 and SW 2 (S 440 ).

In such a case, the discharge terminals of the discharge terminal unit 125 are electrically disconnected from each other, thereby opening connections between each of the first to third battery units 111 , 112 and 113 .

The output terminals of the charger 200 are then connected to the charge terminal unit 124 of the battery pack 100 (S 450 ). Because the respective charge terminals of the charge terminal unit 124 are connected to the terminals of the first to third battery units 111 , 112 and 113 , respectively, the first to third battery units 111 , 112 and 113 are connected in parallel with respect to the charger 200 (S 450 ). Therefore, the first to third battery units 111 , 112 and 113 are charged in a state in which they are connected in parallel (S 450 ).

However, if the output terminals of the charger 200 are connected to the charge terminal unit 124 of the battery pack 100 but the charger 200 is not connected to an external power supply, the level of the voltage detected through the charge recognizing units TB 1 and TB 2 of the connection control unit 130 is low. Therefore, the connection control unit 130 maintains the first to third battery units 111 , 112 and 113 to be connected to each other in series.

3. Discharge Mode

The discharge mode recognition and functionality of the battery pack 100 are similar to the discharge standby mode recognition and functionality. As a result of the functionality of the connection control unit 130 , if the voltage level is low (S 420 B), the connection control unit 130 recognizes a discharge mode (S 460 ).

In such a case, the connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 to connect the first to third battery units 111 , 112 and 113 to each other in series (S 470 ). If the pack discharge terminals P 1 + and P 3 − are connected to an external load, the first to third battery units 111 , 112 and 113 are discharged in a state in which they are connected in series through the pack discharge terminals P 1 + and P 3 − (S 480 ).

The connection control unit 130 performs similar switch control operations depending on whether the battery pack 100 is in a discharge standby mode or a discharge mode. That is to say, since the connection control unit 130 turns on the first and second discharge control switches SW 1 and SW 2 in both the discharge standby mode and the discharge mode, the first to third battery units 111 , 112 and 113 are connected to each other in series in both cases.

Although automatic switching operation control of the battery pack 100 has been described hereinabove, manual switching operation control may also be made without departing from the features of various embodiments.

According to various aspects, battery units are charged by connecting the battery units to each other in parallel during charging, thereby reducing a total charging time of the battery pack, and the battery units are discharged by connecting the battery units to each other in series during discharging, thereby achieving a higher output battery pack.

In addition, according to the present invention, a high-capacity battery pack can be charged using a low-capacity charger. For example, a battery pack having a DC output voltage of 300 V can be charged using a charger having a DC output voltage of 100 V. That is to say, while the first to third battery units are connected in series during discharging, providing for a DC output voltage of 300 V, the first to third battery units are connected in parallel with respect to the charger during charging, thereby charging the first to third battery units having a DC output of 100 V.

Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention.