English:
[0001] There are a variety of different types of battery packs configured to power various types of electronic devices. However, the charging characteristics for the various battery packs differ (e.g., a battery pack that includes three lithium ion cells needs to be charged to a different level than a lithium ion battery that contains four cells). Thus, if a four-cell battery pack is charged to the level required for a three-cell battery pack, the four-cell battery pack will be under-charged, which will generally cause an undesirable shortening of the useful life of the battery pack. Additionally, the physical configuration of a battery charging system (and any device the charging system may be disposed in, such as a notebook computer or other type of electronic device) and the physical configuration of the battery pack itself introduce errors into the battery charging process. For example, contact resistance between the charging system and the battery pack, discrete components that lay between the charging system and terminals of the battery pack, and distributed impedances present in voltage sensing and charging circuits cause the charging system to charge the battery pack to a voltage lower than the maximum allowed for the battery pack.
[0002] FIGURE 1 is a diagram illustrating an embodiment of a battery pack charging system employed in an electronic device to advantage;
[0003] FIGURE 2 is a circuit diagram illustrating an embodiment of a battery pack charging system; and
[0004] FIGURE 3 is a circuit diagram illustrating another embodiment of a battery pack charging system.
[0005] The preferred embodiments of the present invention and the advantages thereof are best understood by referring to FIGURES 1-3 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
[0006] FIGURE 1 is a diagram illustrating an embodiment of a battery pack charging system 10 employed in an electronic device 12 to advantage. In the embodiment illustrated in FIGURE 1 , electronic device 12 comprises a laptop or notebook computer 14. However, it should be understood that embodiments of battery pack charging system 10 may be employed to advantage in a variety of other types of electronic devices and/or configurations such as, but not limited to, a cellular telephone, tablet computer, convertible portable computer, stand-alone battery charger, or any other type of device, portable or non-portable, configured to charge a rechargeable battery pack.
[0007] In the embodiment illustrated in FIGURE 1 , electronic device 12 comprises a battery pack 16 for providing power to electronic device 12; however, it should be understood that electronic device 12 may be otherwise powered (e.g., via an alternating current power source). In FIGURE 1 , battery pack 16 is illustrated as an internal battery pack 16 (i.e., configured to be located or disposed within electronic device 12). However, it should be understood that battery pack 16 may comprise an external battery pack 16 (e.g., a travel battery pack). Battery pack charging system 10 is used to control recharging of battery pack 16. For example, battery pack 16 may comprise any type of rechargeable battery pack such as, but not limited to, a lithium ion, nickel metal hydride, nickel cadmium, lithium ion polymer or other type of battery pack 16. Further, it should be understood that battery pack 16 may comprise different quantities of battery cells and/or different cell chemistries (e.g., lithium ion battery packs 16 having different charge voltage ratings per cell).
[0008] FIGURE 2 is a circuit diagram illustrating an embodiment of battery pack charging system 10. In the embodiment illustrated in FIGURE 2, charging system 10 comprises a charger 20 and a charger controller 22 disposed within electronic device 12. Charger 20 and/or charger controller 22 may comprise hardware, software, firmware, or a combination thereof, and may also comprise a microprocessor or other type of processing element. In FIGURE 2, electronic device 12 comprises terminal contacts 3O1, 3O2and 3O3for removably coupling charger 20 and charger controller 22 to corresponding terminal contacts 32^ 322and switch 40 in the form of field effect transistors (FETs) 44 and 46, respectively, and a fuse 48 coupled in series between terminal contact 32i and battery cells 50 of battery pack 16. In FIGURE 2, three battery cells 50 are illustrated in battery pack 16. However, it should be understood that a greater or fewer quantity of cells 50 may be disposed within battery pack 16.
[0009] In the embodiment illustrated in FIGURE 2, charging system 10 comprises a sensing circuit 60 in the form of a voltage divider having a sensing element 62, such as a sensing resistor 64, and a sensing element 66, such as a sensing resistor 68. In FIGURE 2, sensing element 62 is disposed in electronic device 12 coupled between a feedback path 70 of circuit 60 (extending from terminal contact 3O2to charger controller 22) and terminal contact 3O3. In the embodiment illustrated in FIGURE 2, sensing element 66 is disposed in battery pack 16 and coupled between terminal contact 322and a positive terminal 74 of battery cells 50. Thus, embodiments of system 10 form voltage divider sensing circuit 60 in response to coupling of a particular battery pack 16 to charger 20 and/or charger controller 22. As used herein, "forming" the voltage divider sensing circuit 60 in response to coupling a particular battery pack 16 to charger 20 and/or charger controller 22 shall mean physically linking or coupling together the components used to establish a voltage divider circuit (e.g., sensing elements 62 and 66). In the embodiment illustrated in FIGURE 2, system 10 comprises a current sensing resistor 76 disposed in battery pack 16 and coupled between a negative terminal 78 of battery cells 50 and terminal contact 323.
[0010] In operation, charger controller 22 receives a signal from feedback path 70 of sensing circuit 60 and uses the signal to regulate the voltage applied by charger 20 to battery pack 16 to recharge battery pack 16. For example, charger controller 22 is preferably configured to control the level of recharge voltage supplied by charger 20 based on a predetermined reference voltage level 80 which, in FIGURE 2, is stored in a memory 82 of charger controller 22; however, it should be understood that reference voltage level 80 may be stored in hardware (e.g., in charger controller 22). In operation, charger controller 22 compares the signal received on feedback path 70 to the reference voltage level 80 and, in response to the signal reaching the stored reference voltage level 80 (which is indicative of the desired regulation or clamp voltage of battery pack 16), causes charger 20 to regulate or clamp the voltage at positive terminal 74 of cells 50.
[0011] In the embodiment illustrated in FIGURE 2, sensing element 62 is selected or set to a predetermined value or resistance based on the reference voltage level 80. Sensing element 66 is preferably selected or set to a predetermined value or resistance based on a characteristic of the particular battery pack 16, such as the regulation or clamp voltage of a particular battery pack 16, such that, depending on the value of sensing element 66, charger 20 is controlled to deliver a voltage level to cells 50 equal to (i.e., equal to or approximately equal to) the desired regulation voltage of battery pack 16. For example, sensing element 66 is preferably selected based on a particular battery pack 16 such that the particular combination of sensing elements 62 and 66 results in a desired regulation voltage level for the particular battery pack 16. Thus, for example, if a particular battery pack 16 requires a greater level of regulation charge voltage (e.g., a four-cell battery pack 16 as opposed to a three-cell battery pack 16), the value or resistance of sensing element 66 for a four-cell battery pack 16 is selected to be greater than the value or resistance of sensing element 66 for a three-cell battery pack 16. Accordingly, because of a greater value or resistance of sensing element 66 for a four-cell battery pack 16 than for a three-cell battery pack 16, a greater level of voltage would have to supplied by charger 20 to reach the reference voltage level 80 (e.g., as detected or sensed by charger controller 22 from the signal received on feedback path 70).
[0012] Thus, selecting a value of sensing element 66 for a particular battery pack 16 enables charger 20 to charge to different voltage levels without modification to charger 20. In operation, when the signal on feedback path 70 reaches the reference voltage level 80, charger controller 22 causes charger 20 to regulate the voltage of battery pack 16. Different values or resistances of sensing element 66 for different battery packs 16 combined with a constant value or resistance of sensing element 62 thereby results in different clamp voltages for the different battery packs (i.e., base on the selected sensing element 66). Thus, by selecting sensing element 66 for a particular clamp voltage level for a particular battery pack 16, sensing element 66, in effect, is used to program (or set) the desired voltage at which the charge controller 22/charger 20 clamps the charging voltage for the battery pack 16. Thus, embodiments of system 10 enable at least two different battery packs 16 each having a different regulation charge voltage associated therewith to be removably coupled to charger 20/charge controller 22 (e.g., interchangeably coupled to charger 20/charge controller 22) such that the charger 20 charges the respective battery pack 16 to its regulation charge voltage.
[0013] Embodiments of system 10 also reduce error in detecting or sensing the regulation voltage level that may otherwise be caused by system impedances. For example, as current flows through battery pack 16, impedances caused by contact resistance (e.g., at terminal contacts 32), switches 40 and 42, fuse 48, and other components in the current path generate a voltage drop that is superimposed on the voltage across battery pack 16, which can affect the signal received by charge controller 22 on feedback path 70. Embodiments of system 10 significantly reduce the effect of these impedances by locating and/or otherwise coupling sensing element 66 in close proximity to the positive terminal 74 of battery cells 50. Thus, some or all of the sources of impedance between the sensing element 66 and charger 20 are no longer sensed by sensing circuit 60 (e.g., switch 40 and fuse 48).
[0014] FIGURE 3 is a circuit diagram illustrating another embodiment of battery pack charging system 10. In the embodiment illustrated in FIGURE 3, charging system 10 comprises a differential amplifier 100 formed by an operational amplifier 102, sensing resistor 64, sensing resistor 68, a sensing element 90 (such as a sensing resistor 92), and a sensing element 114 (such as a sensing resistor 116). In FIGURE 3, sensing element 90 is disposed in battery pack 16 and coupled between negative terminal 78 of battery cells 50 and a terminal contact 324of battery pack 16. An input terminal 108 of operational amplifier 100 is coupled to terminal contact 3O2and an input terminal 110 of operational amplifier 100 is coupled to terminal contact 3O4of electronic device 12. In the embodiment illustrated in FIGURE 3, an output 112 of differential amplifier 100 corresponding to feedback path 70 is coupled to charger controller 22, and sensing element 114 is coupled between input terminal 110 and output 112. Preferably, sensing elements 66 and 90 are configured having the same value or resistance. Further, the ratio of values or resistances of sensing element 114 to sensing element 90 is equal (i.e., equal or substantially equal) to the ratio of values or resistances of sensing element 62 to sensing element 66. Because sensing element 90 is coupled close to negative terminal 78 of battery cells 50, the effect of impedance from negative terminal 78 to terminal contact 3O3that would otherwise be introduced into the signal on feedback path 70 is substantially reduced or eliminated.

中文:
[0001]配置为给不同类型的电子装置供电的有多种不同类型的电池组。但是,对于不同电池组来说其充电特性不同(例如,有三个锂离子电芯的电池组需要被充电达到的电平不同于有四个电芯的锂离子电池)。因此,如果四电芯的电池组被充电至三电芯电池组所需充电达到的电平,四电芯电池组将会未充满,这一般将会导致电池组的有用寿命的不希望的缩短。另外,电池充电系统(以及任何配置有充电系统的装置,例如笔记本电脑或其它类型的电子装置)的物理配置和电池组自身的物理配置将给电池充电过程引入差错。例如,充电系统和电池组之间的接触电阻,充电系统和电池组端子之间的离散元件,以及存在于电压检测和充电电路中的分布阻抗导致充电系统将电池组充电至低于电池组最大允许值的电压。
[0002]图1为一个图,描述了有利地用在电子设备中的电池组充电系统的一个实施例;
[0003]图2为一个电路图,描述了电池组充电系统的一个实施例;以及
[0004]图3为一个电路图,描述了电池组充电系统的另一个实施例。
[0005]本发明的优选实施例和其优点通过参考附图1-3可以最好地被理解,不同附图中的相同和相应的部分用相同的附图标记表示。
[0006]图1是一个图,描述了有利地用在电子设备12中的电池组充电系统10的一个实施例。在图1所述的实施例中,电子设备12包括膝上型或笔记本电脑14。但是,应当理解电池组充电系统10的实施例可以被有利地用在多种其他类型的电子设备和/或配置中,例如,但不限于,移动电话,平板电脑,可转换便携式电脑,独立电池充电器,或者任何其他类型的、便携的或非便携的、被配置为对可充电电池组充电的装置。
[0007]在图1所述的实施例中,电子设备12包括用于给电子设备12供电的电池组16;但是,应当理解电子设备12也可以采用其他方式供电(例如,通过交流电源)。在图1中,电池组16被描述为内部的电池组16(即,被配置为位于或设置在电子设备12内)。但是,应当理解电池组16可以包括外部电池组16(例如,旅行电池组)。电池组充电系统10被用于控制电池组16的再充电。例如,电池组16可以包括任何类型的可充电电池组,例如,但不限于,锂离子,镍氢,镍镉,锂离子聚合物或者其他类型的电池组16。更进一步,应当理解电池组16可以包括不同数量的电池电芯和/或不同的电芯化学性质(例如,其中每个电芯具有不同的充电额定电压的锂离子电池组16)。
[0008]图2为一个电路图,描述了电池组充电系统10的一个实施例。在如图2所述的实施例中,充电系统10包括设置在电子设备12中的充电器20以及充电器控制器22。充电器20和/或充电器控制器22可以包括硬件,软件,固件,或其组合,也可以包括微处理器或其它类型的处理器件。在图2中,电子设备12包括端子接触301,302和303,用于可移除地将充电器20和充电器控制器22耦接至电池组16的相应的端子接触321,322和323。在图2所述的实施例中,电池组16包括形式为分别的场效应晶体管(FET)44和46的开关40,以及熔丝48,开关40和熔丝48串联耦接在电池组16的端子接触321和多个电池电芯50之间。在图2中,电池组16中示出有三个电池电芯50。但是,应当理解更多或更少数量的电芯50可以被设置在电池组16中。
[0009]在图2所述的实施例中,充电系统10包括分压器形式的检测电路60,该分压器具有检测元件62,例如检测电阻器64,和检测元件66,例如检测电阻器68。在图2中,检测元件62被设置在电子设备12中连接在电路60的反馈路径70(从端子接触302延伸至充电器控制器22)和端子接触303之间。在图2所述的实施例中,检测元件66被设置在电池组16中并连接在端子接触322和多个电池电芯50的正极端子74之间。这样,系统10的实施例响应特定电池组16与充电器20和/或充电器控制器22的耦接形成分压检测电路60。如在此所用到的,响应特定的电池组16与充电器20和/或充电器控制器22的耦接“形成”分压检测电路60应当理解为,将用于建立分压器电路的这些元件(例如,检测元件62和66)物理连接或耦接在一起。在图2所述的实施例中,系统10包括电流检测电阻器76,其被设置在电池组16中并被耦接在多个电池电芯50的负极端子78和端子接触323之间。
[0010]在操作中,充电器控制器22接收来自检测电路60的反馈路径70的信号并使用这个信号调节由充电器20施加到电池组16以给电池组16充电的电压。例如,充电器控制器22优选地被配置为基于预设的参考电压值80控制由充电器20提供的充电电压的电压值,该参考电压值80在图2中被存储在充电器控制器22的存储器82中;但是,应当理解参考电压值80可以被储存在硬件中(例如,在充电器控制器22中)。在操作中,充电器控制器22将接收自反馈路径70的信号与参考电压值80相比较,并响应该信号达到储存的参考电压值80(其表示电池组16所期望的调节或箝位电压),使得充电器20调节或箝位多个电芯50的正极端子74处的电压。
[0011]在图2所示的实施例中,检测元件62基于参考电压值80被选择或设置在预定的值或电阻。检测元件66优选地基于特定的电池组16的特性,例如特定的电池组16的调节或箝位电压,被选择或设置在预定的值或电阻,使得,取决于检测元件66的值,控制充电器20传送到电芯50的电压值等于(即等于或大致等于)电池组16要求的调节电压。例如,检测元件66优选地基于特定的电池组16被选择,以使检测元件62和66的该特定组合产生特定的电池组16要求的调节电压值。因此,例如,如果特定的电池组16需要更大的调节充电电压(例如,四电芯电池组16而不是三电芯的电池组16),用于四电芯电池组16的检测元件66的值或电阻被选择为大于用于三电芯电池组16的检测元件66的值或电阻。从而,由于用于四电芯电池组16的检测元件66的值或电阻大于用于三电芯电池组16的值或电阻,更大的电压值必将由充电器20提供以达到参考电压值80(例如,如充电器控制器22从反馈路径70上接收的信号检测或感测的)。
[0012]因此,选择用于特定电池组16的检测元件66的值使充电器20能充电至不同的电压值而不需要对充电器20进行更改。在操作中,当反馈路径70上的信号达到参考电压值80时,充电器控制器22使充电器20调节电池组16的电压。用于不同电池组16的检测元件66的不同值或电阻与检测元件62的固定值或电阻相结合从而导致用于不同电池组的不同的箝位电压(即基于所选择的检测元件66)。因此,通过选择用于特定电池组16的特定箝位电压的检测元件66,检测元件66实际上被用于对要求的电压进行编程(或设定),充电器控制器22/充电器20将用于电池组16的充电电压箝位在该要求的电压。因此,系统10的实施例使至少两个不同的、各自具有与其相关联的不同的调节充电电压的电池组16能够可移除地耦接至充电器20/充电器控制器22(例如,可互换地耦接至充电器20/充电器控制器22),以使充电器20将各个电池组16充电至它的调节充电电压。
[0013]系统10的实施例也减少了在检测或感测调节电压值中可能另外由系统阻抗引起的误差。例如,因为电流流过电池组16,由(例如,在端子接触32上的)接触电阻、开关40和42、熔丝48以及其它在电流路径上的元件引起的阻抗产生电压降,该电压降被叠加在电池组16两端的电压上,它能影响在反馈路径70上的被充电器控制器22接收的信号。系统10的实施例通过紧邻多个电池电芯50的正极端子74定位和/或耦接检测元件66,明显减少了这些阻抗的影响。因此,在检测元件66和充电器20之间的部分或所有的阻抗来源不再会被检测电路60检测到(例如,开关40和熔丝48)。
[0014]图3为一个电路图,描述了电池组充电系统10的另一个实施例。在图3所述的实施例中,充电系统10包括差分放大器100,其由运算放大器102、检测电阻器64、检测电阻器68、检测元件90(例如检测电阻器92),以及检测元件114(例如检测电阻器116)构成。在图3中,检测元件90被设置在电池组16中并耦接在多个电池电芯50的负极端子78和电池组16的端子接触324之间。运算放大器100的一个输入端子108被耦接至端子接触302,运算放大器100的一个输入端子110被耦接至电子设备12的端子接触304。在图3所述的实施例中,对应于反馈路径70的差分放大器100的输出112被耦接至充电器控制器22,检测元件114被耦接在输入端子110和输出112之间。优选的,检测元件66和90被设置为具有相同的值或电阻。进一步,检测元件114与检测元件90的值或电阻的比率等于(即相等于或基本相等于)检测元件62与检测元件66的值或电阻的比率。因为检测元件90被紧接多个电池电芯50的负极端子78耦接,否则的话将会被引进反馈路径70上的信号的、从负极端子78至端子接触303的阻抗的影响被明显减少或消除。