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(dian)瓶充電(dian)器原理如(ru)下圖：

充電過程分析：

1.維護充電：

    當電(dian)池(chi)電(dian)壓較低(di)時（可設(she)(she)定，本(ben)電(dian)路(lu)(lu)(lu)預設(she)(she)在9V以下），充電(dian)器工(gong)作(zuo)在小電(dian)流維(wei)護充電(dian)狀態下，工(gong)作(zuo)原理為U1C⑨腳(jiao)（同(tong)相端）電(dian)位低(di)于⑧腳(jiao)（反相端），U1C輸出低(di)電(dian)位，T4截止(zhi)。U1D 11 腳(jiao)電(dian)位約(yue)0.18V．此時充電(dian)電(dian)流約(yue)250mA（恒(heng)流電(dian)路(lu)(lu)(lu)由R14，U1D，T1B周(zhou)邊外圍電(dian)路(lu)(lu)(lu)構成，恒(heng)流原理讀者請自行分析(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(shu)出約1A電流(liu)給電池充電。

3. 限壓浮充：

    當電(dian)(dian)(dian)(dian)(dian)池接近充(chong)足電(dian)(dian)(dian)(dian)(dian)時，充(chong)電(dian)(dian)(dian)(dian)(dian)器自(zi)動(dong)轉入限壓(ya)浮充(chong)狀態下(限壓(ya)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)設定(ding)(ding)為13.8V，如為6V蓄(xu)電(dian)(dian)(dian)(dian)(dian)池，則浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)應設定(ding)(ding)為6.9V)， 此時的充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流會由快速充(chong)電(dian)(dian)(dian)(dian)(dian)狀態下逐(zhu)漸下降，至(zhi)電(dian)(dian)(dian)(dian)(dian)池完(wan)全充(chong)足電(dian)(dian)(dian)(dian)(dian)后，充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流僅為10～30mA，用以補充(chong)電(dian)(dian)(dian)(dian)(dian)池因自(zi)放電(dian)(dian)(dian)(dian)(dian)而損失(shi)的電(dian)(dian)(dian)(dian)(dian)量。

4. 保(bao)護及充電指(zhi)示電路(lu)：

    本(ben)電(dian)(dian)(dian)(dian)路設有反極(ji)性保護電(dian)(dian)(dian)(dian)路，由(you)D4，U1C，U1D，T1及外圍(wei)(wei)元件構成，當電(dian)(dian)(dian)(dian)池反接時，充(chong)電(dian)(dian)(dian)(dian)器(qi)限(xian)制輸(shu)出電(dian)(dian)(dian)(dian)流不致發生事故。充(chong)電(dian)(dian)(dian)(dian)指示由(you)U1A，D7及外圍(wei)(wei)元件構成，充(chong)電(dian)(dian)(dian)(dian)時，D7點(dian)亮(liang)，充(chong)電(dian)(dian)(dian)(dian)器(qi)進入浮充(chong)狀態(tai)后，D7熄滅(mie)，表示充(chong)電(dian)(dian)(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。