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(ya)較低時(shi)(shi)（可(ke)設(she)定，本(ben)電(dian)(dian)(dian)路預(yu)設(she)在9V以下），充(chong)電(dian)(dian)(dian)器工作在小電(dian)(dian)(dian)流維護(hu)充(chong)電(dian)(dian)(dian)狀態下，工作原理(li)為U1C⑨腳（同相端）電(dian)(dian)(dian)位低于(yu)⑧腳（反相端），U1C輸(shu)出低電(dian)(dian)(dian)位，T4截止。U1D 11 腳電(dian)(dian)(dian)位約0.18V．此(ci)時(shi)(shi)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流約250mA（恒流電(dian)(dian)(dian)路由R14，U1D，T1B周(zhou)邊外圍電(dian)(dian)(dian)路構成，恒流原理(li)讀者請自(zi)行分析(xi)）．

2. 快(kuai)速充電(dian)：

    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(shu)出約(yue)1A電(dian)(dian)流給電(dian)(dian)池充電(dian)(dian)。

3. 限壓(ya)浮充：

    當(dang)電(dian)(dian)池接近充(chong)(chong)(chong)足電(dian)(dian)時，充(chong)(chong)(chong)電(dian)(dian)器自動轉(zhuan)入(ru)限壓(ya)浮充(chong)(chong)(chong)狀(zhuang)態(tai)下(限壓(ya)浮充(chong)(chong)(chong)電(dian)(dian)壓(ya)設定為(wei)13.8V，如為(wei)6V蓄電(dian)(dian)池，則浮充(chong)(chong)(chong)電(dian)(dian)壓(ya)應(ying)設定為(wei)6.9V)， 此時的(de)充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)會由快速充(chong)(chong)(chong)電(dian)(dian)狀(zhuang)態(tai)下逐漸(jian)下降，至(zhi)電(dian)(dian)池完全(quan)充(chong)(chong)(chong)足電(dian)(dian)后，充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)僅為(wei)10～30mA，用(yong)以補充(chong)(chong)(chong)電(dian)(dian)池因自放電(dian)(dian)而損失的(de)電(dian)(dian)量。

4. 保護及(ji)充電指示電路(lu)：

    本電(dian)(dian)路(lu)設有反極性(xing)保護(hu)電(dian)(dian)路(lu)，由D4，U1C，U1D，T1及外圍元件(jian)(jian)構(gou)成(cheng)，當電(dian)(dian)池反接時，充(chong)電(dian)(dian)器(qi)(qi)限制(zhi)輸出電(dian)(dian)流不(bu)致(zhi)發生事故(gu)。充(chong)電(dian)(dian)指(zhi)示(shi)(shi)由U1A，D7及外圍元件(jian)(jian)構(gou)成(cheng)，充(chong)電(dian)(dian)時，D7點亮(liang)，充(chong)電(dian)(dian)器(qi)(qi)進入浮(fu)充(chong)狀態后，D7熄滅，表示(shi)(shi)充(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。