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(li)如(ru)下圖：

充電過程分析：

1.維護充電：

    當電(dian)池電(dian)壓(ya)較低(di)(di)時(shi)（可設定，本(ben)電(dian)路預設在9V以下），充電(dian)器(qi)工作在小電(dian)流維護充電(dian)狀態下，工作原(yuan)理為U1C⑨腳（同(tong)相(xiang)端）電(dian)位(wei)(wei)低(di)(di)于⑧腳（反相(xiang)端），U1C輸出(chu)低(di)(di)電(dian)位(wei)(wei)，T4截止(zhi)。U1D 11 腳電(dian)位(wei)(wei)約0.18V．此時(shi)充電(dian)電(dian)流約250mA（恒流電(dian)路由R14，U1D，T1B周邊(bian)外圍電(dian)路構成(cheng)，恒流原(yuan)理讀者請自行(xing)分(fen)析(xi)）．

2. 快速充電：

    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(shu)出約1A電流給(gei)電池充電。

3. 限壓浮充：

    當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)接(jie)近充(chong)(chong)足電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器自(zi)動轉入限壓浮(fu)充(chong)(chong)狀態下(限壓浮(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓設定為(wei)(wei)13.8V，如(ru)為(wei)(wei)6V蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)，則浮(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓應設定為(wei)(wei)6.9V)， 此時的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)會(hui)由快速充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態下逐漸下降，至電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)完全(quan)充(chong)(chong)足電(dian)(dian)(dian)(dian)(dian)(dian)(dian)后，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)僅為(wei)(wei)10～30mA，用以(yi)補充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)因自(zi)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)而損失的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。

4. 保護(hu)及(ji)充電指示電路：

    本(ben)電路設(she)有反極性保(bao)護電路，由D4，U1C，U1D，T1及(ji)外圍元件構(gou)成，當電池反接(jie)時，充(chong)電器(qi)(qi)限制(zhi)輸出(chu)電流不(bu)致發(fa)生(sheng)事故。充(chong)電指示由U1A，D7及(ji)外圍元件構(gou)成，充(chong)電時，D7點(dian)亮(liang)，充(chong)電器(qi)(qi)進入(ru)浮充(chong)狀態(tai)后，D7熄滅，表示充(chong)電結束。

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。