檢測(ce)普通(tong)(tong)(tong)鋅錳干(gan)電(dian)(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)(dian)量(liang)是否充足(zu)，通(tong)(tong)(tong)常(chang)有兩種(zhong)方(fang)(fang)法。第一(yi)種(zhong)方(fang)(fang)法是通(tong)(tong)(tong)過(guo)測(ce)量(liang)電(dian)(dian)(dian)(dian)池(chi)瞬時短路電(dian)(dian)(dian)(dian)流來估算(suan)電(dian)(dian)(dian)(dian)池(chi)的(de)(de)內(nei)阻(zu)(zu)，進而判(pan)斷(duan)電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)量(liang)是否充足(zu)；第二種(zhong)方(fang)(fang)法是用電(dian)(dian)(dian)(dian)流表串聯一(yi)只阻(zu)(zu)值適(shi)當的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)，通(tong)(tong)(tong)過(guo)測(ce)量(liang)電(dian)(dian)(dian)(dian)池(chi)的(de)(de)放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流計算(suan)出電(dian)(dian)(dian)(dian)池(chi)內(nei)阻(zu)(zu)，從(cong)而判(pan)斷(duan)電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)量(liang)是否充足(zu)。

第一種方法的最大優點是簡便，用萬用表的大電流檔就可直接判斷出干電池的電量，缺點是測試電流很大，遠遠超過干電池允許放電電流的極限值，在一定程度上影響干電池使用壽命。第二種方法的優點是測試電流小，安全性好，一般不會對干電池的使用壽命產生不良影響，缺點是較為麻煩。
筆者用(yong)MF47型萬用(yong)表對一(yi)節新(xin)2號(hao)干電(dian)池(chi)和一(yi)節舊2號(hao)干電(dian)池(chi)分(fen)別(bie)用(yong)上述兩種方法(fa)進行測試(shi)對比(bi)。假設ro是(shi)干電(dian)池(chi)內阻(zu)，RO是(shi)電(dian)流表內阻(zu)，用(yong)第(di)二種測試(shi)方法(fa)時，RF是(shi)附加的(de)串聯電(dian)阻(zu)，阻(zu)值3Ω，功(gong)率2W。

      實測(ce)結(jie)果如下。新2號電(dian)池E=1.58V（用(yong)(yong)(yong)2.5V直流(liu)(liu)電(dian)壓(ya)(ya)檔(dang)測(ce)量），電(dian)壓(ya)(ya)表內阻為50kΩ，遠(yuan)大(da)于ro，故(gu)可近似認(ren)為1.58V是電(dian)池的電(dian)動勢，或稱開路電(dian)壓(ya)(ya)。用(yong)(yong)(yong)第一種(zhong)方法時(shi)，萬(wan)用(yong)(yong)(yong)表置5A直流(liu)(liu)電(dian)流(liu)(liu)檔(dang)，電(dian)表內阻RO=0.06Ω，測(ce)得電(dian)流(liu)(liu)為3.3A。所以(yi) ro+RO=1.58V÷3.3A≈0.48Ω，ro=0.48-0.06=0.42Ω。用(yong)(yong)(yong)第二種(zhong)方法時(shi)，測(ce)得電(dian)流(liu)(liu)為 0.395A，RF+ro+RO=1.58V÷0.395A=4Ω，電(dian)流(liu)(liu)500mA檔(dang)內阻為0.6Ω，所以(yi)ro=4-3-0.6=0.4Ω。

舊2號電池用第一種方法測量時，先測得開路電壓E=1.2V，電表內阻RO=6Ω，讀數為6.5mA，萬用表置50mA直流電流檔，ro+RO=1.2V÷0.0065A≈184.6Ω，ro=184.6-6=178.6Ω。用第二種方法，測得電流為 6.3mA，ro+RO+RF=1.2V÷0.0063A=190.5Ω，ro=190.5-6-3=181.5Ω。
顯然兩種測試方法的(de)(de)(de)結果(guo)(guo)基本一致(zhi)。最終計(ji)算結果(guo)(guo)的(de)(de)(de)微小差別是由于讀(du)數誤差、電阻RF的(de)(de)(de)誤差以及(ji)接觸(chu)電阻等多方面因素(su)造成的(de)(de)(de)，這種微小誤差不致(zhi)影響對電池電量(liang)(liang)的(de)(de)(de)判斷。如(ru)(ru)果(guo)(guo)被測電池的(de)(de)(de)容量(liang)(liang)小、電壓高（例(li)如(ru)(ru)15V、9V疊層電池），則應(ying)將RF的(de)(de)(de)阻值(zhi)適應(ying)增大。