最近幾年，電動車普遍使用了所謂三段式充電器，第(di)(di)一(yi)個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)恒(heng)流(liu)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)，第(di)(di)二個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)恒(heng)壓(ya)(ya)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)，第(di)(di)三(san)(san)個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)涓流(liu)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)。從電(dian)(dian)子技術角度針(zhen)對電(dian)(dian)池(chi)而(er)言：第(di)(di)一(yi)個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)充電(dian)(dian)限(xian)流(liu)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)，第(di)(di)二個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)高恒(heng)壓(ya)(ya)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)，第(di)(di)三(san)(san)個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)叫(jiao)(jiao)低恒(heng)壓(ya)(ya)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)比較貼切。第(di)(di)二階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)和第(di)(di)三(san)(san)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)轉(zhuan)換(huan)(huan)時，面板指示燈(deng)(deng)相應變換(huan)(huan)，大(da)多數充電(dian)(dian)器(qi)第(di)(di)一(yi)、二階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)是(shi)紅(hong)燈(deng)(deng)，第(di)(di)三(san)(san)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)變綠燈(deng)(deng)。第(di)(di)二階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)和第(di)(di)三(san)(san)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)的(de)(de)相互(hu)轉(zhuan)換(huan)(huan)是(shi)由充電(dian)(dian)電(dian)(dian)流(liu)決定(ding)的(de)(de)，大(da)于某電(dian)(dian)流(liu)進(jin)入第(di)(di)一(yi)第(di)(di)二階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)，小(xiao)于某電(dian)(dian)流(liu)進(jin)入第(di)(di)三(san)(san)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)。這(zhe)個(ge)電(dian)(dian)流(liu)叫(jiao)(jiao)轉(zhuan)換(huan)(huan)電(dian)(dian)流(liu)，也叫(jiao)(jiao)轉(zhuan)折電(dian)(dian)流(liu)。

    買新(xin)充電(dian)(dian)(dian)(dian)(dian)器要(yao)檢查三(san)(san)段(duan)式充電(dian)(dian)(dian)(dian)(dian)器的(de)(de)(de)三(san)(san)個(ge)(ge)重(zhong)要(yao)參數(shu)，第(di)(di)(di)(di)一個(ge)(ge)重(zhong)要(yao)參數(shu)是(shi)涓流(liu)階段(duan)的(de)(de)(de)低恒(heng)壓(ya)值(zhi)(zhi)，第(di)(di)(di)(di)二個(ge)(ge)重(zhong)要(yao)參數(shu)是(shi)第(di)(di)(di)(di)二階段(duan)的(de)(de)(de)高恒(heng)壓(ya)值(zhi)(zhi)，第(di)(di)(di)(di)三(san)(san)個(ge)(ge)重(zhong)要(yao)參數(shu)是(shi)轉換電(dian)(dian)(dian)(dian)(dian)流(liu)。這三(san)(san)個(ge)(ge)重(zhong)要(yao)參數(shu)與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池數(shu)目有(you)關，與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)容量Ah有(you)關，與(yu)(yu)溫度(du)有(you)關，與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池種類有(you)關。用戶一般(ban)可以自己測(ce)得第(di)(di)(di)(di)三(san)(san)階段(duan)的(de)(de)(de)低恒(heng)壓(ya)值(zhi)(zhi)。方法(fa)是(shi)，不接電(dian)(dian)(dian)(dian)(dian)池，給充電(dian)(dian)(dian)(dian)(dian)器加市電(dian)(dian)(dian)(dian)(dian)，用數(shu)字萬(wan)用表的(de)(de)(de)200V直流(liu)電(dian)(dian)(dian)(dian)(dian)壓(ya)檔測(ce)的(de)(de)(de)輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)。另(ling)兩(liang)個(ge)(ge)參數(shu)高恒(heng)壓(ya)值(zhi)(zhi)和轉折電(dian)(dian)(dian)(dian)(dian)流(liu)一般(ban)需要(yao)專用工具才能測(ce)得。