鋰離子可充電電池是20世紀開發成功的新型高能電池，相對于傳統的鎳鎘電池和鎳氫電池而言，具有容量大、工作電壓高、工作溫度范圍寬、循環壽命長、自放電率低、無記憶效應、無污染等優點，自問世以來已廣泛應用于軍事和民用小型電器中，如移動電話、便攜式計算機、攝像機、照相機等，部分代替了傳統電池。單節鋰離子電池的電壓約為3．6V，容量也不可能無限大，因此，常將單節鋰離子電池進(jin)行串(chuan)(chuan)、并聯處理(li)，以滿足(zu)不同場合的要求。為(wei)了確保(bao)鋰離子電(dian)(dian)(dian)(dian)(dian)池(chi)安(an)全可(ke)靠的使(shi)用(yong)，本文介紹了一種(zhong)嚴格(ge)、周(zhou)密(mi)的充(chong)、放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)系統的設計方(fang)案。該方(fang)案采用(yong)充(chong)電(dian)(dian)(dian)(dian)(dian)、放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)分離的控制方(fang)式，具有兩級(ji)單節過(guo)充(chong)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)、單節過(guo)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)、兩級(ji)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)過(guo)電(dian)(dian)(dian)(dian)(dian)流保(bao)護(hu)、放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)短(duan)路保(bao)護(hu)、放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)溫度(du)(du)保(bao)護(hu)、充(chong)電(dian)(dian)(dian)(dian)(dian)溫度(du)(du)保(bao)護(hu)、充(chong)電(dian)(dian)(dian)(dian)(dian)防(fang)反(fan)接保(bao)護(hu)、充(chong)電(dian)(dian)(dian)(dian)(dian)時禁(jin)止放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)等功(gong)能，可(ke)適(shi)用(yong)于各種(zhong)三／四節鋰離子可(ke)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)池(chi)串(chuan)(chuan)聯使(shi)用(yong)的場合。

　　1 系統概述

　　該保(bao)護(hu)系(xi)(xi)(xi)統采用(yong)精(jing)工(gong)電(dian)(dian)(dian)(dian)(dian)子(zi)三／四節(jie)串聯鋰(li)離子(zi)可充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)池專用(yong)充(chong)、放(fang)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)ICS-8254構建一(yi)級保(bao)護(hu)。S-8254系(xi)(xi)(xi)列內(nei)(nei)置高(gao)精(jing)度電(dian)(dian)(dian)(dian)(dian)壓檢(jian)測(ce)(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)和(he)(he)延遲(chi)(chi)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)，針(zhen)對各節(jie)電(dian)(dian)(dian)(dian)(dian)池進行(xing)高(gao)精(jing)度電(dian)(dian)(dian)(dian)(dian)壓檢(jian)測(ce)(ce)(ce)(ce)，實現(xian)單(dan)節(jie)過(guo)(guo)(guo)(guo)(guo)(guo)充(chong)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)和(he)(he)單(dan)節(jie)過(guo)(guo)(guo)(guo)(guo)(guo)放(fang)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)，并具(ju)備三段(duan)過(guo)(guo)(guo)(guo)(guo)(guo)電(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)(ce)(ce)(ce)功能，通過(guo)(guo)(guo)(guo)(guo)(guo)外接電(dian)(dian)(dian)(dian)(dian)容可設置過(guo)(guo)(guo)(guo)(guo)(guo)充(chong)電(dian)(dian)(dian)(dian)(dian)檢(jian)測(ce)(ce)(ce)(ce)延遲(chi)(chi)時間(jian)、過(guo)(guo)(guo)(guo)(guo)(guo)放(fang)電(dian)(dian)(dian)(dian)(dian)檢(jian)測(ce)(ce)(ce)(ce)延遲(chi)(chi)時間(jian)和(he)(he)過(guo)(guo)(guo)(guo)(guo)(guo)電(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)(ce)(ce)(ce)延遲(chi)(chi)時間(jian)1(過(guo)(guo)(guo)(guo)(guo)(guo)電(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)(ce)(ce)(ce)延遲(chi)(chi)時間(jian)2和(he)(he)過(guo)(guo)(guo)(guo)(guo)(guo)電(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)(ce)(ce)(ce)延遲(chi)(chi)時間(jian)3在芯(xin)片內(nei)(nei)部被固定)。該系(xi)(xi)(xi)統采用(yong)精(jing)工(gong)電(dian)(dian)(dian)(dian)(dian)子(zi)S-8244系(xi)(xi)(xi)列內(nei)(nei)置高(gao)精(jing)度電(dian)(dian)(dian)(dian)(dian)壓檢(jian)測(ce)(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)和(he)(he)延遲(chi)(chi)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)的鋰(li)離子(zi)可充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)池二級保(bao)護(hu)專用(yong)IC實現(xian)電(dian)(dian)(dian)(dian)(dian)池的單(dan)節(jie)二級充(chong)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)，其保(bao)護(hu)延遲(chi)(chi)時間(jian)可通過(guo)(guo)(guo)(guo)(guo)(guo)外接電(dian)(dian)(dian)(dian)(dian)容的容值來(lai)設置。

　　S-8254通(tong)過SEL端(duan)子(zi)可(ke)以實現(xian)電(dian)(dian)池三(san)節串(chuan)聯用(yong)或四節串(chuan)聯用(yong)的(de)(de)切換；S-8244則通(tong)過電(dian)(dian)阻R22短路第(di)四節電(dian)(dian)池電(dian)(dian)壓檢(jian)測端(duan)子(zi)VCC3和(he)VSS即可(ke)用(yong)作三(san)節電(dian)(dian)池串(chuan)聯使用(yong)時的(de)(de)二級保(bao)護。

　　2 各保護功能(neng)的實現

S-8254系列充、放電保護電壓和過電流檢測電壓以50mV為進階單位，S-8244系列過充電檢測電壓以5mV為進階單位，系統根據不同場合的使用需求，可以選擇相應適合的型號。現以圖1保護系統為例，采用S-8254AAVFT和S-8244AAPFN作為保護IC，具體說明各保護功能的實現過程。
 

　　圖1為四節電池串(chuan)聯(lian)使用時的保護系統原理圖。

　　2．1 過(guo)放電保護

　　通(tong)常(chang)狀態(tai)下(xia)，S-8254放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控制用端(duan)(duan)子(zi)DOP為(wei)VSS(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池4的負電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya))電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)，放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOS管(guan)QDISl，QDIS2處于導(dao)通(tong)狀態(tai)，系統(tong)可正(zheng)(zheng)常(chang)進行放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)工作(zuo)。當檢測(ce)到某(mou)節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)低于2．7V(VDLn)，且(qie)這種狀態(tai)保持在TDL(TDL時(shi)(shi)間由(you)過(guo)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)檢測(ce)延遲端(duan)(duan)子(zi)CDT外接電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容CS決定)以(yi)上(shang)時(shi)(shi)，DOP端(duan)(duan)子(zi)的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)變為(wei)VDD(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池1的正(zheng)(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya))電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)，放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOS管(guan)關閉，停止(zhi)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這種狀態(tai)稱為(wei)過(guo)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)。進入過(guo)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)后，VMP端(duan)(duan)子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)經電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻R3由(you)負載下(xia)拉至(zhi)VDD／2以(yi)下(xia)，S-8254轉為(wei)休眠(mian)(mian)狀態(tai)；斷開負載后，VMP端(duan)(duan)子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)經電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻R9、充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOS管(guan)QCHRl和QCHR2由(you)VDD上(shang)拉至(zhi)VDD／2以(yi)上(shang)且(qie)低于VDD，S-8254退出休眠(mian)(mian)狀態(tai)。當所有電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)都在3．0V(VDUn)以(yi)上(shang)時(shi)(shi)，過(guo)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)被(bei)解除，系統(tong)恢復正(zheng)(zheng)常(chang)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)工作(zuo)。

　　2．2 過電流、短(duan)路保護

　　該系(xi)統采(cai)用2個并聯(lian)的(de)20mΩ功率電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻RS1，RS2用于(yu)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)檢(jian)測(ce)(ce)(ce)。當放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)大于(yu)20A時(shi)(shi)(shi)，過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)1，2檢(jian)測(ce)(ce)(ce)端子VINI和VSS之(zhi)間(jian)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)差大于(yu)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位1VI0V1(O．2V)，且(qie)這種狀(zhuang)態(tai)保(bao)持在(zai)TIOVl(TIOVl時(shi)(shi)(shi)間(jian)由過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)1檢(jian)測(ce)(ce)(ce)延遲(chi)端子CDT外接電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)C3決定)以(yi)上(shang)時(shi)(shi)(shi)，DOP端子的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)變為(wei)VDD電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位，放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOS管關閉(bi)，停(ting)止放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，進(jin)(jin)入過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)1保(bao)護狀(zhuang)態(tai)。在(zai)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)狀(zhuang)態(tai)下，VMP端子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經(jing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻R3由負載(zai)下拉至VSS；斷開負載(zai)后，VMP端子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經(jing)IC內部(bu)RVMD電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻被(bei)上(shang)拉至過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位3VIOV3(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)1的(de)正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)VC1～1．2V)以(yi)上(shang)，過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)狀(zhuang)態(tai)解除(chu)，系(xi)統恢復正常放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。當放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)大于(yu)50A時(shi)(shi)(shi)，VINI和VSS之(zhi)間(jian)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)差大于(yu)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位2VIOV2(0．5V)，且(qie)這種狀(zhuang)態(tai)保(bao)持在(zai)TIOV2(1ms)以(yi)上(shang)時(shi)(shi)(shi)，進(jin)(jin)入過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)2保(bao)護狀(zhuang)態(tai)。當負載(zai)出現短(duan)路(lu)時(shi)(shi)(shi)，過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)3檢(jian)測(ce)(ce)(ce)端子VMP的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)被(bei)瞬間(jian)拉至VIOV3以(yi)下(檢(jian)測(ce)(ce)(ce)延遲(chi)時(shi)(shi)(shi)間(jian)TI0V3為(wei)300μs)，系(xi)統進(jin)(jin)入短(duan)路(lu)保(bao)護(過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)3保(bao)護)狀(zhuang)態(tai)。

　　2．3 過充電保護

為了確保電池的安全性，該系統對于過充電狀態采取了兩級保護措施。首先，當檢測到某節電池電壓高于4．05V(VCU2n)，且這種狀態保持在TCU2(TCU2時間由S-8244過充電檢測延遲端子ICT外接電容C16決定)以上時，S-8244充電控制用端子CO輸出動態“H”，二級充電MOS管QCHR2關閉，停止充電，這種狀態稱為過充電狀態；進入過充電狀態后，當所有電池電壓都在3．80V(VCL2n)以下時，過充電狀態解除。若因某種原因導致S-8244保護失效，則S-8254過充電保護生效，當檢測到某節電池電壓高于4．25V(VCUln)，且這種狀態保持在TCUl(TCUl時間由S-8254過充電檢測延遲端子CCT外接電容C2決定)以上時，S-8254充電控制用端子COP變為高阻抗，一級充電MOS管QCHRl的G極被外接電阻R2拉高，QCHRl關閉，進入過充電狀態；當所有電池電壓都在4．15V(VCLln)以下時，過充電狀態解除。
2．4 充(chong)電溫度保護

　　為(wei)(wei)(wei)了確保(bao)充電(dian)時(shi)的安全性和延長電(dian)池的使用(yong)壽(shou)命，電(dian)池的充電(dian)溫(wen)度(du)(du)應控制(zhi)在(zai)O～45℃之(zhi)間為(wei)(wei)(wei)宜。該系統(tong)采用(yong)一(yi)個負溫(wen)度(du)(du)系數的NTC溫(wen)度(du)(du)傳感器RES和一(yi)個2路(lu)(lu)比較器LM393來實現充電(dian)溫(wen)度(du)(du)保(bao)護(hu)，其原理圖如圖2所示(shi)：當充電(dian)溫(wen)度(du)(du)位(wei)于(yu)(yu)O～45℃之(zhi)間時(shi)，LM393的兩路(lu)(lu)比較器輸(shu)出(chu)均為(wei)(wei)(wei)高阻(zu)(zu)態，PNP型三極管(guan)Q1關斷，對(dui)充電(dian)電(dian)路(lu)(lu)不產生(sheng)影響；隨(sui)著溫(wen)度(du)(du)的升高，RES阻(zu)(zu)值(zhi)逐漸(jian)變小，當溫(wen)度(du)(du)大于(yu)(yu)45℃時(shi)，LM393下面(mian)(mian)一(yi)路(lu)(lu)比較器反轉，輸(shu)出(chu)低(di)電(dian)平，通過(guo)二極管(guan)D6將Q1的B極拉低(di)，Q1導通，充電(dian)MOS管(guan)QCHRl的G極C_QCHR被強制(zhi)拉高，QCHRl關閉(bi)，停止(zhi)充電(dian)；同樣，隨(sui)著溫(wen)度(du)(du)的降低(di)，RES阻(zu)(zu)值(zhi)逐漸(jian)變大，當溫(wen)度(du)(du)小于(yu)(yu)O℃時(shi)，LM393上(shang)面(mian)(mian)一(yi)路(lu)(lu)比較器輸(shu)出(chu)低(di)電(dian)平，通過(guo)二極管(guan)D5將Q1導通，從而關閉(bi)QCHRl，停止(zhi)充電(dian)。

　　2．5 其(qi)他保(bao)護功能

　　該系統通過一些(xie)簡單有效的電路設計，巧(qiao)妙地實現了所(suo)需(xu)的某些(xie)保護功能(neng)。

　　2．5．1 放電溫度保護

　　為了(le)確保電(dian)(dian)(dian)(dian)(dian)池的使用(yong)安全性，需對電(dian)(dian)(dian)(dian)(dian)池的放(fang)電(dian)(dian)(dian)(dian)(dian)溫(wen)(wen)度進行限制。該(gai)系統在(zai)放(fang)電(dian)(dian)(dian)(dian)(dian)MOS管QDISl，QDIS2的G極C_QDIS和VDD之間(jian)連接了(le)一個常(chang)開型可恢復溫(wen)(wen)度保險絲(si)F1。通(tong)常(chang)狀(zhuang)態下F1保持開路。不影響正常(chang)放(fang)電(dian)(dian)(dian)(dian)(dian)；當電(dian)(dian)(dian)(dian)(dian)池溫(wen)(wen)度高于(yu)75℃時，F1閉合，C_QDIS與(yu)VDD導通(tong)．放(fang)電(dian)(dian)(dian)(dian)(dian)MOS管關閉，停止放(fang)電(dian)(dian)(dian)(dian)(dian)，從而實(shi)現放(fang)電(dian)(dian)(dian)(dian)(dian)溫(wen)(wen)度保護功(gong)能。

　　2．5．2 充電防反接保護

　　若誤將充電器的(de)正、負極反(fan)接入系統(tong)中，則會由(you)充(chong)電(dian)(dian)器和電(dian)(dian)池共(gong)同形(xing)成(cheng)一個(ge)大(da)電(dian)(dian)流回(hui)路，導致元器件損壞，甚至帶來(lai)更大(da)的(de)安(an)全(quan)危(wei)害。該系統(tong)在充(chong)電(dian)(dian)回(hui)路中串接進一個(ge)防反(fan)接二極管D1，這樣即使充(chong)電(dian)(dian)器反(fan)接，因此時CHRl的(de)電(dian)(dian)位將高(gao)于CHR+，由(you)于二極管D1的(de)存在，系統(tong)將構不成(cheng)回(hui)路，從而對其起到了保護(hu)作用。

　　2．5．3 充電時禁(jin)止放電

　　系統在連接充電器進行充電的過程中若允許其進行放電工作，可能會帶來不必要的安全隱患，因此該系統在充電器的正極輸入端CHR+和C_QDIS之間接入了一個二極管D4。在未連接充電器時，CHR+懸空，對放電工作不產生影響；當連接充電器進行充電時，C_QDIS通過D4被CHR+強制(zhi)拉(la)高，QDISl，QDIS2關閉，禁止放電。

　　鋰離(li)子可充電(dian)電(dian)池(chi)以其(qi)特有(you)的(de)性能(neng)優勢已經在多(duo)個領域中得到(dao)了(le)普遍應(ying)用，可以預計其(qi)必(bi)將成(cheng)為21世紀的(de)主要(yao)動(dong)力(li)電(dian)源之一(yi)。隨著鋰離(li)子可充電(dian)電(dian)池(chi)工業的(de)發展，保護(hu)系統作為其(qi)不(bu)可分(fen)割的(de)一(yi)部分(fen)必(bi)將起(qi)到(dao)越來(lai)越重要(yao)的(de)作用。