最近幾年，電動車普遍使用了所謂三段式充電器，第(di)(di)一個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)恒流(liu)(liu)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)，第(di)(di)二(er)(er)個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)恒壓階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)，第(di)(di)三個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)涓流(liu)(liu)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)。從電(dian)(dian)子(zi)技術(shu)角度(du)針對電(dian)(dian)池而(er)言(yan)：第(di)(di)一個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)充(chong)(chong)電(dian)(dian)限流(liu)(liu)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)，第(di)(di)二(er)(er)個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)高恒壓階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)，第(di)(di)三個階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)叫(jiao)(jiao)(jiao)(jiao)低恒壓階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)比較貼切。第(di)(di)二(er)(er)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)和(he)第(di)(di)三階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)轉(zhuan)換時，面板指(zhi)示燈(deng)相應變(bian)換，大多數充(chong)(chong)電(dian)(dian)器第(di)(di)一、二(er)(er)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)是紅燈(deng)，第(di)(di)三階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)變(bian)綠(lv)燈(deng)。第(di)(di)二(er)(er)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)和(he)第(di)(di)三階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)的(de)相互轉(zhuan)換是由充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)決定的(de)，大于(yu)某(mou)電(dian)(dian)流(liu)(liu)進入(ru)第(di)(di)一第(di)(di)二(er)(er)階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)，小于(yu)某(mou)電(dian)(dian)流(liu)(liu)進入(ru)第(di)(di)三階(jie)(jie)(jie)段(duan)(duan)(duan)(duan)(duan)。這個電(dian)(dian)流(liu)(liu)叫(jiao)(jiao)(jiao)(jiao)轉(zhuan)換電(dian)(dian)流(liu)(liu)，也叫(jiao)(jiao)(jiao)(jiao)轉(zhuan)折電(dian)(dian)流(liu)(liu)。

    買新(xin)充電(dian)器(qi)(qi)(qi)要(yao)(yao)檢查三(san)段(duan)式(shi)充電(dian)器(qi)(qi)(qi)的三(san)個重(zhong)(zhong)要(yao)(yao)參(can)數(shu)，第(di)一個重(zhong)(zhong)要(yao)(yao)參(can)數(shu)是(shi)涓流(liu)階段(duan)的低(di)恒(heng)壓(ya)值(zhi)，第(di)二(er)個重(zhong)(zhong)要(yao)(yao)參(can)數(shu)是(shi)第(di)二(er)階段(duan)的高(gao)恒(heng)壓(ya)值(zhi)，第(di)三(san)個重(zhong)(zhong)要(yao)(yao)參(can)數(shu)是(shi)轉換電(dian)流(liu)。這三(san)個重(zhong)(zhong)要(yao)(yao)參(can)數(shu)與電(dian)池(chi)(chi)(chi)(chi)數(shu)目有(you)關(guan)，與電(dian)池(chi)(chi)(chi)(chi)的容量Ah有(you)關(guan)，與溫度有(you)關(guan)，與電(dian)池(chi)(chi)(chi)(chi)種類有(you)關(guan)。用(yong)戶一般可以自(zi)己(ji)測得第(di)三(san)階段(duan)的低(di)恒(heng)壓(ya)值(zhi)。方法是(shi)，不接電(dian)池(chi)(chi)(chi)(chi)，給充電(dian)器(qi)(qi)(qi)加市電(dian)，用(yong)數(shu)字萬用(yong)表的200V直流(liu)電(dian)壓(ya)檔測的輸出電(dian)壓(ya)。另(ling)兩個參(can)數(shu)高(gao)恒(heng)壓(ya)值(zhi)和轉折(zhe)電(dian)流(liu)一般需要(yao)(yao)專用(yong)工具才能測得。