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(ping)充(chong)電器原理如下圖：

充電過程分析：

1.維護充電：

    當電(dian)(dian)池電(dian)(dian)壓較低時（可設定(ding)，本電(dian)(dian)路(lu)預設在9V以(yi)下），充電(dian)(dian)器工作在小(xiao)電(dian)(dian)流(liu)維護充電(dian)(dian)狀態下，工作原理(li)為U1C⑨腳（同(tong)相端）電(dian)(dian)位(wei)低于⑧腳（反相端），U1C輸出(chu)低電(dian)(dian)位(wei)，T4截止(zhi)。U1D 11 腳電(dian)(dian)位(wei)約(yue)(yue)0.18V．此(ci)時充電(dian)(dian)電(dian)(dian)流(liu)約(yue)(yue)250mA（恒(heng)(heng)流(liu)電(dian)(dian)路(lu)由R14，U1D，T1B周邊外圍電(dian)(dian)路(lu)構成，恒(heng)(heng)流(liu)原理(li)讀者請自行分析(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，充電器恒定輸出約(yue)1A電(dian)流給電(dian)池充電(dian)。

3. 限壓浮充：

    當(dang)電(dian)(dian)池接近充(chong)足電(dian)(dian)時，充(chong)電(dian)(dian)器自(zi)動轉入限(xian)壓(ya)浮(fu)(fu)充(chong)狀(zhuang)態下(限(xian)壓(ya)浮(fu)(fu)充(chong)電(dian)(dian)壓(ya)設定為13.8V，如為6V蓄(xu)電(dian)(dian)池，則浮(fu)(fu)充(chong)電(dian)(dian)壓(ya)應設定為6.9V)， 此時的(de)充(chong)電(dian)(dian)電(dian)(dian)流會由快(kuai)速充(chong)電(dian)(dian)狀(zhuang)態下逐(zhu)漸下降，至電(dian)(dian)池完全充(chong)足電(dian)(dian)后，充(chong)電(dian)(dian)電(dian)(dian)流僅為10～30mA，用以補充(chong)電(dian)(dian)池因自(zi)放(fang)電(dian)(dian)而(er)損失的(de)電(dian)(dian)量。

4. 保(bao)護及充(chong)電(dian)指示電(dian)路：

    本電(dian)路(lu)設有反極性保護電(dian)路(lu)，由D4，U1C，U1D，T1及外圍(wei)元(yuan)(yuan)件構成，當(dang)電(dian)池反接時，充(chong)電(dian)器限制輸出電(dian)流不致發(fa)生事故。充(chong)電(dian)指(zhi)示(shi)由U1A，D7及外圍(wei)元(yuan)(yuan)件構成，充(chong)電(dian)時，D7點亮，充(chong)電(dian)器進入(ru)浮(fu)充(chong)狀態(tai)后，D7熄滅，表示(shi)充(chong)電(dian)結束(shu)。

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。