快速充(chong)(chong)電是指能在(zai)(zai)1～5h內(nei)使蓄電池達(da)到(dao)或接近(jin)完(wan)全充(chong)(chong)電狀(zhuang)態的(de)一種充(chong)(chong)電方法(fa)。常用(yong)于(yu)牽引(yin)用(yong)蓄電池需(xu)要在(zai)(zai)較短時間內(nei)恢復完(wan)全充(chong)(chong)電狀(zhuang)態時的(de)充(chong)(chong)電。快速充(chong)(chong)電對(dui)蓄電池的(de)性能和(he)壽命有損。蓄電池的(de)正常充(chong)(chong)電耗時約10～20h，如何能快速充(chong)(chong)電而不損害蓄電池的(de)性能和(he)壽命，是人們關注的(de)熱門(men)研究課題。

快速充電電路特點
　　1、輸出電壓設定好后(例如36V)，若被充電瓶極板脫落斷開，造成某組電池不通，或出現短路，則電瓶端電壓即降低或為零，這時充電器將無輸出電流。
　　2、若被充電瓶電壓偏離設定電壓，如設定電壓為36V，誤接24V、12V、6V電瓶等，充電器也無輸出電流，若設定為24V誤接為36V電瓶，由于充電器輸出電壓低于電瓶電壓，因而也不能向電瓶充電。 　　
　　3、充電器兩輸出端若短路時，由于充電器中可控硅SCR的觸發電路不能工作，因而可控硅不導通，輸出電流為零。 　　
　　4、若使用時誤將電瓶正負極接反，則可控硅觸發電路反向截止，無觸發信號，可控硅不導通，輸出電流為零。 　　
　　5、采用脈沖充電，有利于延長電瓶壽命。由于低壓交流電經全波整流后是脈動直流，只有當其波峰電壓大于電瓶電壓時，可控硅才會導通，而當脈動直流電壓處于波谷區時，可控硅反偏截止，停止向電瓶充電，因而流過電瓶的是脈動直流電。 　　
　　6、快速充電，充滿自停。由于剛開始充電時電瓶兩端電壓較低，因而充電電流較大。當電瓶即將充足時(36V電瓶端電壓可達44V)，由于充電電壓越來越接近脈動直流輸出電壓的波峰值，則充電電流也會越來越小，自動變為涓流充電。當電瓶兩端電壓被充到整流輸出的波峰最大值時，充電過程停止。經試驗，三節電動車蓄電池36V(12V／12Ah三節串聯)，用該充電器只需幾個小時即可充滿。 　　
　　7、電路簡(jian)單、易于制(zhi)作，幾乎不用(yong)維(wei)護(hu)及維(wei)修(xiu)。

　　快速充電電路原理
　　AC220V市電(dian)(dian)(dian)(dian)(dian)經變壓(ya)(ya)器(qi)T1降壓(ya)(ya)，經D1-D4全波整(zheng)流后，供給充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路工作。當輸出(chu)(chu)端按(an)正確極性(xing)接入設定的被充(chong)電(dian)(dian)(dian)(dian)(dian)瓶(ping)后，若整(zheng)流輸出(chu)(chu)脈動(dong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的每個半波峰值超過電(dian)(dian)(dian)(dian)(dian)瓶(ping)的輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，則(ze)可控硅SCR經Q的集電(dian)(dian)(dian)(dian)(dian)極電(dian)(dian)(dian)(dian)(dian)流觸發導(dao)(dao)通(tong)，電(dian)(dian)(dian)(dian)(dian)流經可控硅給電(dian)(dian)(dian)(dian)(dian)瓶(ping)充(chong)電(dian)(dian)(dian)(dian)(dian)。脈動(dong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)接近電(dian)(dian)(dian)(dian)(dian)瓶(ping)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)時，可控硅關斷，停止(zhi)充(chong)電(dian)(dian)(dian)(dian)(dian)。調節R4，可調節晶體管Q的導(dao)(dao)通(tong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，一般可將R4由大到(dao)小調整(zheng)到(dao)Q導(dao)(dao)通(tong)能(neng)觸發可控硅(導(dao)(dao)通(tong))即可。圖中發光(guang)管D5用作電(dian)(dian)(dian)(dian)(dian)源指示，而D6用作充(chong)電(dian)(dian)(dian)(dian)(dian)指示。