SOC指荷電狀態，也叫剩余電量，代表的是電池使用(yong)一段時(shi)(shi)間或長期擱置不(bu)用(yong)后的剩余(yu)容量(liang)與(yu)其完(wan)(wan)全(quan)(quan)充(chong)電(dian)狀(zhuang)態的容量(liang)的比值，常用(yong)百分數(shu)表(biao)示。其取值范圍為0~1，當SOC=0時(shi)(shi)表(biao)示電(dian)池(chi)放電(dian)完(wan)(wan)電(dian)了，需要充(chong)電(dian)，當SOC=1時(shi)(shi)表(biao)示電(dian)池(chi)完(wan)(wan)全(quan)(quan)充(chong)滿。鋰離子(zi)電(dian)池(chi)SOC不(bu)能(neng)直接(jie)測量(liang)，只能(neng)通(tong)過電(dian)池(chi)端電(dian)壓、充(chong)放電(dian)電(dian)流(liu)及內阻等參數(shu)來估算其大小。而這些(xie)參數(shu)還(huan)會受到電(dian)池(chi)老化、環境溫度(du)變(bian)化及汽(qi)車行駛狀(zhuang)態等多(duo)種不(bu)確定(ding)因素的影響，因此準確的SOC估計已成為電(dian)動汽(qi)車發展中亟待(dai)解決的問題(ti)，比如(ru)電(dian)量(liang)跳變(bian)，即將(jiang)停車的時(shi)(shi)候，掃了一眼電(dian)量(liang)，還(huan)剩下(xia)50%，估計回(hui)程(cheng)勉強夠用(yong)了。過一會回(hui)來發動車子(zi)，發現電(dian)量(liang)指示在了40%，貌似回(hui)不(bu)去了。

突(tu)然掉電(dian)，電(dian)量(liang)(liang)還有30%的(de)(de)時候，一腳加速(su)，驟然報警電(dian)量(liang)(liang)過低，停車了。電(dian)池組SOC的(de)(de)準確(que)性，一直是(shi)電(dian)動汽(qi)車用戶(hu)詬(gou)病的(de)(de)重點，在網絡(luo)論壇上時常能看(kan)到(dao)，電(dian)動汽(qi)車車主說又(you)被放到(dao)半路的(de)(de)抱怨帖。發展多年的(de)(de)電(dian)動汽(qi)車，電(dian)池組SOC的(de)(de)準確(que)估計仍然沒有做的(de)(de)特(te)別好。

電(dian)池組SOC作為(wei)充(chong)放電(dian)的(de)重要閾(yu)值，對(dui)電(dian)池包(bao)起到調節和保護作用。充(chong)電(dian)過(guo)程(cheng)中，如(ru)果電(dian)池包(bao)電(dian)量(liang)過(guo)低，比(bi)如(ru)低于10%，則充(chong)電(dian)電(dian)流不能(neng)馬力全開，而是限(xian)流充(chong)電(dian)，直(zhi)至(zhi)達到正常(chang)電(dian)量(liang)范圍，方(fang)可(ke)放開限(xian)制(zhi)。放電(dian)階段，當(dang)電(dian)量(liang)已經比(bi)較低，但仍然在放電(dian)截止(zhi)電(dian)量(liang)以(yi)上，比(bi)如(ru)低至(zhi)20%SOC，一般會(hui)限(xian)制(zhi)功(gong)率輸(shu)出，防止(zhi)大電(dian)流造成系統(tong)觸及停(ting)車電(dian)壓，并且期望以(yi)最節能(neng)的(de)方(fang)式運行，跑更遠(yuan)的(de)距離。

SOH是(shi)指(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)容(rong)(rong)量(liang)衰減剩余量(liang)、健康度、性(xing)能(neng)狀(zhuang)態，簡(jian)單的(de)(de)說(shuo)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)使用一段時(shi)間后性(xing)能(neng)參數(shu)與標(biao)稱參數(shu)的(de)(de)比值，新出(chu)廠(chang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)為(wei)100%，完全(quan)報廢為(wei)0%。是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)從滿充狀(zhuang)態下(xia)以一定的(de)(de)倍率放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)到(dao)截止(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓所(suo)放出(chu)的(de)(de)容(rong)(rong)量(liang)與其所(suo)對(dui)應的(de)(de)標(biao)稱容(rong)(rong)量(liang)的(de)(de)比值，簡(jian)單的(de)(de)理解為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)極限(xian)容(rong)(rong)量(liang)大小(xiao)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)內阻(zu)(zu)與SOH存在(zai)一定的(de)(de)關(guan)系。SOH越低，鋰離子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)內阻(zu)(zu)越大，通(tong)過檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流、溫度等數(shu)據，間接計算出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)內阻(zu)(zu)值，然后根據SOH與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)內阻(zu)(zu)的(de)(de)關(guan)系計算求得SOH。但是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)內阻(zu)(zu)在(zai)SOH變(bian)化(hua)范圍不(bu)大時(shi)變(bian)化(hua)不(bu)明顯，而當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)老化(hua)嚴(yan)重時(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值的(de)(de)變(bian)化(hua)較(jiao)(jiao)大，因而該方法在(zai)SOH變(bian)化(hua)較(jiao)(jiao)小(xiao)時(shi)，測量(liang)的(de)(de)誤差會較(jiao)(jiao)大。