由于密封鉛酸蓄電池的諸多優點，因此獲得了廣泛應用．然而密封鉛酸蓄電池的充電技術似乎不被看重，因充電方式不合理而造成電池過早報廢的情況普遍存在．有鑒于此，筆者設計制作了一款二階段恒流限壓式鉛酸蓄電池充電器。 

電瓶充電器原(yuan)理如下圖：

充電過程分析：

1.維護充電：

    當電(dian)(dian)(dian)池電(dian)(dian)(dian)壓較低時（可設(she)定，本電(dian)(dian)(dian)路(lu)預設(she)在(zai)9V以下(xia)），充電(dian)(dian)(dian)器工作在(zai)小電(dian)(dian)(dian)流(liu)維(wei)護充電(dian)(dian)(dian)狀態下(xia)，工作原理為U1C⑨腳（同相端）電(dian)(dian)(dian)位低于⑧腳（反相端），U1C輸出(chu)低電(dian)(dian)(dian)位，T4截止。U1D 11 腳電(dian)(dian)(dian)位約0.18V．此時充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)約250mA（恒流(liu)電(dian)(dian)(dian)路(lu)由(you)R14，U1D，T1B周(zhou)邊外圍電(dian)(dian)(dian)路(lu)構(gou)成，恒流(liu)原理讀者請自行分(fen)析）．

2. 快速(su)充電：

    隨著維護充電繼續，電池電壓逐漸升高，當電池電壓超過9V時，充電器轉入大電流快充模式下，U1C⑨腳（同相端）電位高于⑧腳（反相端），U1C輸出高電位，T4導通，U1D 11 腳電位約為0.48V，充電器恒定輸出(chu)約1A電(dian)流給電(dian)池充電(dian)。

3. 限壓浮充：

    當電(dian)(dian)(dian)池(chi)(chi)接近充足(zu)(zu)電(dian)(dian)(dian)時，充電(dian)(dian)(dian)器自動轉入(ru)限壓浮(fu)充狀態(tai)下(xia)(限壓浮(fu)充電(dian)(dian)(dian)壓設(she)定為(wei)13.8V，如為(wei)6V蓄(xu)電(dian)(dian)(dian)池(chi)(chi)，則浮(fu)充電(dian)(dian)(dian)壓應設(she)定為(wei)6.9V)， 此(ci)時的充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)會由快速充電(dian)(dian)(dian)狀態(tai)下(xia)逐漸下(xia)降，至電(dian)(dian)(dian)池(chi)(chi)完(wan)全(quan)充足(zu)(zu)電(dian)(dian)(dian)后，充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)僅為(wei)10～30mA，用以補充電(dian)(dian)(dian)池(chi)(chi)因(yin)自放電(dian)(dian)(dian)而損失的電(dian)(dian)(dian)量。

4. 保護及充電(dian)指示電(dian)路：

    本電(dian)(dian)路(lu)設(she)有(you)反(fan)極性保護(hu)電(dian)(dian)路(lu)，由(you)D4，U1C，U1D，T1及外圍元(yuan)件構(gou)成，當電(dian)(dian)池反(fan)接(jie)時(shi)，充(chong)(chong)電(dian)(dian)器限制(zhi)輸出(chu)電(dian)(dian)流不(bu)致發生(sheng)事故。充(chong)(chong)電(dian)(dian)指示由(you)U1A，D7及外圍元(yuan)件構(gou)成，充(chong)(chong)電(dian)(dian)時(shi)，D7點亮(liang)，充(chong)(chong)電(dian)(dian)器進(jin)入浮充(chong)(chong)狀態(tai)后，D7熄滅(mie)，表示充(chong)(chong)電(dian)(dian)結束。

5. 本電路略為修改電路參數即可任意調整充電電流，浮充電壓以滿足不同規格電池的需要。