電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)組制造商來說，針對電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)供電(dian)(dian)(dian)(dian)系統(tong)構建(jian)安(an)全且可靠的(de)(de)產品是至(zhi)(zhi)關重(zhong)要(yao)的(de)(de)。電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)包(bao)中(zhong)的(de)(de)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)管理電(dian)(dian)(dian)(dian)路(lu)可以監(jian)控(kong)鋰離(li)子電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)運行(xing)狀(zhuang)(zhuang)態(tai)，包(bao)括了電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)阻(zu)抗、溫度、單(dan)(dan)元電(dian)(dian)(dian)(dian)壓、充電(dian)(dian)(dian)(dian)和放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流以及充電(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態(tai)等(deng)，以為系統(tong)提供詳(xiang)細的(de)(de)剩余運轉時間和電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)健康狀(zhuang)(zhuang)況(kuang)信息(xi)，確(que)(que)保系統(tong)作出正確(que)(que)的(de)(de)決策。此外，為了改進電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)安(an)全性能(neng)，即使只有(you)(you)一種故障發生，例(li)如過電(dian)(dian)(dian)(dian)流、短路(lu)、單(dan)(dan)元和電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)包(bao)的(de)(de)電(dian)(dian)(dian)(dian)壓過高、溫度過高等(deng)，系統(tong)也會關閉兩個(ge)和鋰離(li)子電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)串聯的(de)(de)背(bei)靠背(bei)（back-to-back）保護MOSFET，將電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)單(dan)(dan)元斷開。基(ji)于阻(zu)抗跟蹤(zong)技術的(de)(de)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)管理單(dan)(dan)元（BMS）會在整個(ge)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)使用周期(qi)內監(jian)控(kong)單(dan)(dan)元阻(zu)抗和電(dian)(dian)(dian)(dian)壓失衡，并有(you)(you)可能(neng)檢(jian)測電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)微小(xiao)短路(lu)（micro-short），防止電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)單(dan)(dan)元造成火災乃(nai)至(zhi)(zhi)爆炸。

鋰離子電池安全

       過高的工作溫度將加速電池的老化，并可能導致鋰離子電池包的熱失控（thermal run-away）及爆炸。對于鋰離子電池高度活性化的含能材料來說，這一點是備受關注的。大電流的過度充電及短路都有可能造成電池溫度的快速上升。鋰離子電池過(guo)度充電期間，活躍(yue)得金屬鋰(li)(li)沉積在電池的正極(ji)(ji)(ji)，其材(cai)料(liao)(liao)(liao)極(ji)(ji)(ji)大的增(zeng)加了爆炸的危險性，因為(wei)鋰(li)(li)將有(you)可(ke)能與(yu)多(duo)種(zhong)材(cai)料(liao)(liao)(liao)起反應(ying)而爆炸，包括了電解液及陰(yin)極(ji)(ji)(ji)材(cai)料(liao)(liao)(liao)。例如(ru)，鋰(li)(li)/碳插層混合物（intercalated compound）與(yu)水發生反應(ying)，并釋放(fang)出(chu)氫(qing)氣，氫(qing)氣有(you)可(ke)能被(bei)反應(ying)放(fang)熱所(suo)引(yin)燃。陰(yin)極(ji)(ji)(ji)材(cai)料(liao)(liao)(liao)，諸如(ru)LiCoO2，在溫(wen)度超過(guo)175℃的熱失控溫(wen)度限（4.3V單元電壓(ya)）時(shi)，也(ye)將開始與(yu)電解液發生反應(ying)。

      鋰離(li)子(zi)(zi)電(dian)池(chi)使(shi)用很薄的(de)(de)(de)微孔膜（micro-porous film）材料(liao)，例如聚烯烴，進行(xing)電(dian)池(chi)正負極(ji)的(de)(de)(de)電(dian)子(zi)(zi)隔離(li)，因為(wei)(wei)此類(lei)材料(liao)具有卓越的(de)(de)(de)力學(xue)性(xing)能(neng)(neng)、化學(xue)穩定性(xing)以及(ji)可接受的(de)(de)(de)價格。聚烯烴的(de)(de)(de)熔點范圍較低，為(wei)(wei)135℃至(zhi) 165℃，使(shi)得(de)(de)聚烯烴適用于作(zuo)為(wei)(wei)熱(re)保險(xian)（fuse）材料(liao)。隨著(zhu)溫(wen)度的(de)(de)(de)升高并達到(dao)聚合體(ti)的(de)(de)(de)熔點，材料(liao)的(de)(de)(de)多(duo)孔性(xing)將(jiang)失效(xiao)，其目(mu)的(de)(de)(de)是使(shi)得(de)(de)鋰離(li)子(zi)(zi)無(wu)法在電(dian)極(ji)之(zhi)間流(liu)動，從而關斷電(dian)池(chi)。同時，熱(re)敏陶瓷（PCT）設備(bei)以及(ji)安全(quan)排出口(kou)（safety vent）為(wei)(wei)鋰離(li)子(zi)(zi)電(dian)池(chi)提供了額外(wai)的(de)(de)(de)保護。電(dian)池(chi)的(de)(de)(de)外(wai)殼，一般作(zuo)為(wei)(wei)負極(ji)接線端，通(tong)常(chang)為(wei)(wei)典型的(de)(de)(de)鍍鎳(nie)金(jin)屬板。在殼體(ti)密封(feng)的(de)(de)(de)情況(kuang)下，金(jin)屬微粒(li)將(jiang)可能(neng)(neng)污染電(dian)池(chi)的(de)(de)(de)內部。隨著(zhu)時間的(de)(de)(de)推移(yi)，微粒(li)有可能(neng)(neng)遷移(yi)至(zhi)隔離(li)器，并使(shi)得(de)(de)電(dian)池(chi)陽(yang)極(ji)與(yu)陰極(ji)之(zhi)間的(de)(de)(de)絕(jue)緣層老(lao)化。而陽(yang)極(ji)與(yu)陰極(ji)之(zhi)間的(de)(de)(de)微小短(duan)路將(jiang)允許電(dian)子(zi)(zi)肆意的(de)(de)(de)流(liu)動，并最終(zhong)使(shi)電(dian)池(chi)失效(xiao)。絕(jue)大多(duo)數情況(kuang)下，此類(lei)失效(xiao)等同于電(dian)池(chi)無(wu)法供電(dian)且功(gong)能(neng)(neng)完全(quan)終(zhong)止。在少數情況(kuang)下，電(dian)池(chi)有可能(neng)(neng)過熱(re)、熔斷、著(zhu)火乃至(zhi)爆炸。這就是近期(qi)所報道的(de)(de)(de)電(dian)池(chi)故障的(de)(de)(de)主要根源，并使(shi)得(de)(de)眾多(duo)的(de)(de)(de)廠(chang)商不得(de)(de)不將(jiang)其產品召回。

電池管理單元（BMS）以及電池保護

      電(dian)(dian)(dian)池材料的(de)(de)(de)(de)不(bu)斷開發提(ti)升(sheng)了熱失(shi)控的(de)(de)(de)(de)上限溫度。另一方(fang)面，雖然(ran)電(dian)(dian)(dian)池必(bi)須通(tong)過(guo)(guo)(guo)嚴格的(de)(de)(de)(de)UL安全(quan)測試，例(li)如UL1642，但提(ti)供正確的(de)(de)(de)(de)充電(dian)(dian)(dian)狀態并很(hen)好的(de)(de)(de)(de)應對多(duo)種(zhong)有(you)可能(neng)出現的(de)(de)(de)(de)電(dian)(dian)(dian)子原件故(gu)障仍然(ran)是系統設計人員的(de)(de)(de)(de)職(zhi)責所在。過(guo)(guo)(guo)電(dian)(dian)(dian)壓、過(guo)(guo)(guo)電(dian)(dian)(dian)流、短路(lu)、過(guo)(guo)(guo)熱狀態以及外(wai)部分立元(yuan)件的(de)(de)(de)(de)故(gu)障都有(you)可能(neng)引起電(dian)(dian)(dian)池突變的(de)(de)(de)(de)失(shi)效。這就意味著需要(yao)采取多(duo)重的(de)(de)(de)(de)保護――在同一電(dian)(dian)(dian)池包內具有(you)至少兩個獨立的(de)(de)(de)(de)保護電(dian)(dian)(dian)路(lu)或機制。同時，還希望(wang)具備用于(yu)檢測電(dian)(dian)(dian)池內部微小短路(lu)的(de)(de)(de)(de)電(dian)(dian)(dian)子電(dian)(dian)(dian)路(lu)以避免(mian)電(dian)(dian)(dian)池故(gu)障。

     電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)計(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路設計(ji)(ji)(ji)用(yong)(yong)于精確的(de)(de)(de)指示可(ke)用(yong)(yong)的(de)(de)(de)鋰(li)離子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)。該(gai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路獨(du)特(te)的(de)(de)(de)算(suan)法(fa)允許(xu)實(shi)時的(de)(de)(de)追蹤(zong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池包(bao)的(de)(de)(de)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)變化、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池阻抗、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)、溫度以(yi)(yi)及(ji)其它(ta)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路信息。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)計(ji)(ji)(ji)自動的(de)(de)(de)計(ji)(ji)(ji)算(suan)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)速率(lv)、自放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)以(yi)(yi)及(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池單(dan)(dan)(dan)元(yuan)老化，在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池使用(yong)(yong)壽命期(qi)限內實(shi)現了高(gao)(gao)(gao)精度的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)計(ji)(ji)(ji)量(liang)(liang)(liang)。例(li)如，一系列(lie)專利的(de)(de)(de)阻抗追蹤(zong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)計(ji)(ji)(ji)，包(bao)括bq20z70，bq20z80以(yi)(yi)及(ji)bq20z90，均可(ke)在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池壽命期(qi)限內提(ti)供高(gao)(gao)(gao)達1%精度的(de)(de)(de)計(ji)(ji)(ji)量(liang)(liang)(liang)。單(dan)(dan)(dan)個熱(re)敏電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻被用(yong)(yong)于監(jian)測鋰(li)離子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)溫度，以(yi)(yi)實(shi)現電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池單(dan)(dan)(dan)元(yuan)的(de)(de)(de)過熱(re)保(bao)護，并用(yong)(yong)于充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)限定。例(li)如，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池單(dan)(dan)(dan)元(yuan)一般不(bu)允許(xu)在(zai)(zai)(zai)低于0℃或(huo)高(gao)(gao)(gao)于45℃的(de)(de)(de)溫度范(fan)圍內充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，且不(bu)允許(xu)在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池單(dan)(dan)(dan)元(yuan)溫度高(gao)(gao)(gao)于65℃時放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。如檢測到(dao)過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)或(huo)過熱(re)狀態，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)計(ji)(ji)(ji)IC將指令控制AFE關閉充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOSFET Q1及(ji)Q2。當檢測到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池欠壓(ya)（under-voltage）狀態時，則將指令控制AFE關閉放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOSFET Q2，且同時保(bao)持充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)MOSFET開啟(qi)，以(yi)(yi)允許(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

     AFE的主要任(ren)務是(shi)對過載、短(duan)(duan)路(lu)(lu)的檢(jian)測，并保護充(chong)電(dian)及(ji)放電(dian)MOSFET、電(dian)池單元(yuan)以(yi)及(ji)其(qi)它線路(lu)(lu)上(shang)的元(yuan)件，避免(mian)過電(dian)流(liu)(liu)狀(zhuang)(zhuang)態(tai)。過載檢(jian)測用(yong)于(yu)檢(jian)測電(dian)池放電(dian)流(liu)(liu)向(xiang)上(shang)的過電(dian)流(liu)(liu)（OC），同時(shi)，短(duan)(duan)路(lu)(lu)（SC）檢(jian)測用(yong)于(yu)檢(jian)測充(chong)電(dian)及(ji)放電(dian)流(liu)(liu)向(xiang)上(shang)的過電(dian)流(liu)(liu)。AFE電(dian)路(lu)(lu)的過載和(he)短(duan)(duan)路(lu)(lu)限定以(yi)及(ji)延(yan)遲時(shi)間均可(ke)通過電(dian)量計數(shu)據閃存(cun)編程(cheng)設(she)定。當檢(jian)測到過載或短(duan)(duan)路(lu)(lu)狀(zhuang)(zhuang)態(tai)，且達到了程(cheng)序設(she)定的延(yan)遲時(shi)間，則(ze)充(chong)電(dian)及(ji)放電(dian)MOSFET Q1及(ji)Q2將被關閉，詳細的狀(zhuang)(zhuang)態(tai)信息將存(cun)儲(chu)于(yu)AFE的狀(zhuang)(zhuang)態(tai)寄存(cun)器，從而(er)電(dian)量計可(ke)讀取并調(diao)查導(dao)致故障的原因。

對于計量2、3或4個鋰離子電池包的(de)電(dian)(dian)(dian)(dian)(dian)量計芯片(pian)集解決(jue)方(fang)案來說，AFE起了(le)很重要的(de)作用。AFE提(ti)供(gong)了(le)所需(xu)(xu)的(de)所有高壓接口以及硬(ying)件電(dian)(dian)(dian)(dian)(dian)流保護特(te)性。所提(ti)供(gong)的(de)I2C兼容接口允許(xu)電(dian)(dian)(dian)(dian)(dian)量計訪(fang)問AFE寄存器并配置AFE的(de)保護特(te)性。AFE還(huan)集成了(le)電(dian)(dian)(dian)(dian)(dian)池(chi)單元(yuan)平衡(heng)控制(zhi)。多數情(qing)況下(xia)，在(zai)多單元(yuan)電(dian)(dian)(dian)(dian)(dian)池(chi)包中，每(mei)個(ge)獨立電(dian)(dian)(dian)(dian)(dian)池(chi)單元(yuan)的(de)電(dian)(dian)(dian)(dian)(dian)荷狀態(tai)（SOC）彼此不同，從(cong)而導致了(le)不平衡(heng)單元(yuan)間的(de)電(dian)(dian)(dian)(dian)(dian)壓差別。AFE針對每(mei)一(yi)(yi)的(de)電(dian)(dian)(dian)(dian)(dian)池(chi)單元(yuan)整合(he)了(le)旁(pang)通(tong)通(tong)路。此類旁(pang)通(tong)通(tong)路可(ke)用于降低至每(mei)一(yi)(yi)單元(yuan)的(de)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，從(cong)而為電(dian)(dian)(dian)(dian)(dian)池(chi)單元(yuan)充電(dian)(dian)(dian)(dian)(dian)期間的(de)SOC平衡(heng)提(ti)供(gong)了(le)條件。基于阻抗追蹤(zong)電(dian)(dian)(dian)(dian)(dian)量計對每(mei)一(yi)(yi)電(dian)(dian)(dian)(dian)(dian)池(chi)單元(yuan)化(hua)學電(dian)(dian)(dian)(dian)(dian)荷狀態(tai)的(de)確定，可(ke)在(zai)需(xu)(xu)要單元(yuan)平衡(heng)時做(zuo)出正確的(de)決(jue)策。

       具有不同激活時間的(de)多極過(guo)電(dian)(dian)流保(bao)護限(xian)（如圖2所示）使得電(dian)(dian)池包保(bao)護更為強(qiang)健(jian)。電(dian)(dian)量計(ji)具有兩層(ceng)(ceng)的(de)充電(dian)(dian)/放電(dian)(dian)過(guo)電(dian)(dian)流保(bao)護設定，而(er)AFE則提供了第三層(ceng)(ceng)的(de)放電(dian)(dian)過(guo)電(dian)(dian)流保(bao)護。在(zai)短路狀態(tai)下，MOSFET及電(dian)(dian)池可能在(zai)數秒內毀壞，電(dian)(dian)量計(ji)芯片集完全(quan)依靠AFE來自動的(de)關斷(duan)MOSFET，以免產生毀壞。

當電(dian)(dian)(dian)(dian)量(liang)計(ji)IC及其(qi)(qi)所關聯的AFE提供過(guo)(guo)電(dian)(dian)(dian)(dian)壓(ya)保(bao)護時，電(dian)(dian)(dian)(dian)壓(ya)監測(ce)的采樣特性(xing)限制(zhi)了(le)此類保(bao)護系統的響(xiang)應(ying)時間(jian)。絕大多數應(ying)用(yong)要(yao)求能(neng)快速響(xiang)應(ying)，且實時、獨立(li)的過(guo)(guo)電(dian)(dian)(dian)(dian)壓(ya)監測(ce)器，并與(yu)電(dian)(dian)(dian)(dian)量(liang)計(ji)、AFE協同運作(zuo)。該監測(ce)器獨立(li)于電(dian)(dian)(dian)(dian)量(liang)計(ji)及AFE，監測(ce)每(mei)一電(dian)(dian)(dian)(dian)池單(dan)元的電(dian)(dian)(dian)(dian)壓(ya)，并針(zhen)對每(mei)一達(da)到硬件(jian)編碼(ma)過(guo)(guo)電(dian)(dian)(dian)(dian)壓(ya)限的電(dian)(dian)(dian)(dian)池單(dan)元提供邏輯電(dian)(dian)(dian)(dian)平輸(shu)出。過(guo)(guo)電(dian)(dian)(dian)(dian)壓(ya)保(bao)護的響(xiang)應(ying)時間(jian)取(qu)決于外部延遲電(dian)(dian)(dian)(dian)容的大小。在(zai)典型的應(ying)用(yong)中，秒量(liang)級保(bao)護器的輸(shu)出將觸(chu)發(fa)化學保(bao)險絲(si)或其(qi)(qi)它失(shi)效保(bao)護設備(bei)，以永(yong)久性(xing)的將鋰離子電(dian)(dian)(dian)(dian)池與(yu)系統分離。

電(dian)(dian)池(chi)包永(yong)久性(xing)的(de)(de)(de)(de)(de)失(shi)效(xiao)保(bao)(bao)護(hu)(hu)(hu)對(dui)于(yu)電(dian)(dian)池(chi)管(guan)(guan)理(li)單(dan)元(yuan)來說，很重要(yao)的(de)(de)(de)(de)(de)一點是要(yao)為(wei)非(fei)正常狀態下的(de)(de)(de)(de)(de)電(dian)(dian)池(chi)包提供(gong)趨(qu)于(yu)保(bao)(bao)守的(de)(de)(de)(de)(de)關斷。永(yong)久性(xing)的(de)(de)(de)(de)(de)失(shi)效(xiao)保(bao)(bao)護(hu)(hu)(hu)包括(kuo)了過電(dian)(dian)流的(de)(de)(de)(de)(de)放電(dian)(dian)及充電(dian)(dian)故障(zhang)狀態下的(de)(de)(de)(de)(de)安(an)全(quan)、過熱的(de)(de)(de)(de)(de)放電(dian)(dian)及充電(dian)(dian)狀態下的(de)(de)(de)(de)(de)安(an)全(quan)、過電(dian)(dian)壓(ya)的(de)(de)(de)(de)(de)故障(zhang)狀態（峰值(zhi)電(dian)(dian)壓(ya)）以及電(dian)(dian)池(chi)平衡故障(zhang)、短接放電(dian)(dian)FET故障(zhang)、充電(dian)(dian)MOSFET故障(zhang)狀態下的(de)(de)(de)(de)(de)安(an)全(quan)。制造商可選擇(ze)任意組合上述的(de)(de)(de)(de)(de)永(yong)久性(xing)失(shi)效(xiao)保(bao)(bao)護(hu)(hu)(hu)。當檢測到任意的(de)(de)(de)(de)(de)此類故障(zhang)，則保(bao)(bao)護(hu)(hu)(hu)設備將熔(rong)斷化學保(bao)(bao)險(xian)絲(si)，以使(shi)得電(dian)(dian)池(chi)包永(yong)久性(xing)的(de)(de)(de)(de)(de)失(shi)效(xiao)。作為(wei)電(dian)(dian)子(zi)元(yuan)件故障(zhang)的(de)(de)(de)(de)(de)外部失(shi)效(xiao)驗證，電(dian)(dian)池(chi)管(guan)(guan)理(li)單(dan)元(yuan)設計用于(yu)檢測充電(dian)(dian)及放電(dian)(dian)MOSFET Q1及Q2的(de)(de)(de)(de)(de)失(shi)效(xiao)與(yu)否。如果(guo)任意充電(dian)(dian)或放電(dian)(dian)MOSFET短路，則化學保(bao)(bao)險(xian)絲(si)也(ye)將熔(rong)斷。

      據報道，電(dian)(dian)(dian)池內部(bu)的(de)(de)微小(xiao)(xiao)(xiao)短(duan)(duan)(duan)(duan)路(lu)也是導致(zhi)近期多起電(dian)(dian)(dian)池召回的(de)(de)主要原因(yin)。如何檢測電(dian)(dian)(dian)池內部(bu)的(de)(de)微小(xiao)(xiao)(xiao)短(duan)(duan)(duan)(duan)路(lu)并防止電(dian)(dian)(dian)池著(zhu)火乃至爆炸呢？外殼封閉處(chu)理過程(cheng)中，金屬微粒及(ji)其它雜質有可(ke)能污(wu)染電(dian)(dian)(dian)池內部(bu)，從而引起電(dian)(dian)(dian)池內部(bu)的(de)(de)微小(xiao)(xiao)(xiao)短(duan)(duan)(duan)(duan)路(lu)。內部(bu)的(de)(de)微小(xiao)(xiao)(xiao)短(duan)(duan)(duan)(duan)路(lu)將極大地增(zeng)加電(dian)(dian)(dian)池的(de)(de)自放(fang)電(dian)(dian)(dian)速率，使得開路(lu)電(dian)(dian)(dian)壓較(jiao)之正(zheng)常狀態下的(de)(de)電(dian)(dian)(dian)池單元(yuan)(yuan)有所降(jiang)低(di)。阻抗追蹤電(dian)(dian)(dian)量計(ji)監測開路(lu)電(dian)(dian)(dian)壓，并從而檢測電(dian)(dian)(dian)池單元(yuan)(yuan)的(de)(de)非均衡性――當(dang)不同電(dian)(dian)(dian)池單元(yuan)(yuan)的(de)(de)開路(lu)電(dian)(dian)(dian)壓差異超過預先(xian)設置的(de)(de)限定值。當(dang)出現此類(lei)失效時，將產生永久性失效的(de)(de)告(gao)警并斷開MOSFET，化學保險(xian)絲也可(ke)配置為(wei)熔斷。上(shang)述(shu)行為(wei)將使得電(dian)(dian)(dian)池包(bao)無法作(zuo)為(wei)供電(dian)(dian)(dian)源并因(yin)此屏蔽了電(dian)(dian)(dian)池包(bao)內部(bu)的(de)(de)微小(xiao)(xiao)(xiao)短(duan)(duan)(duan)(duan)路(lu)電(dian)(dian)(dian)池單元(yuan)(yuan)，從而防止了災害的(de)(de)發(fa)生。

小結

電(dian)(dian)池(chi)管理單元(yuan)對于確保終端(duan)用戶的安全性是至關重要的。強(qiang)健(jian)的多(duo)極(ji)保護(hu)――過電(dian)(dian)壓(ya)、過電(dian)(dian)流(liu)、過熱、電(dian)(dian)池(chi)單元(yuan)非(fei)均(jun)衡以(yi)及MOSFET失效監測，極(ji)大地(di)改善了電(dian)(dian)池(chi)包的安全性。通過監測電(dian)(dian)池(chi)單元(yuan)的開環電(dian)(dian)壓(ya)，阻抗追蹤技術可檢測電(dian)(dian)池(chi)內部的微小短路(lu)，并(bing)進而永久性的失效電(dian)(dian)池(chi)，確保了終端(duan)用戶的安全。