檢測(ce)普(pu)通(tong)鋅錳干(gan)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)電(dian)(dian)(dian)(dian)(dian)量(liang)是(shi)否(fou)充(chong)足(zu)，通(tong)常有(you)兩種(zhong)方法。第一種(zhong)方法是(shi)通(tong)過(guo)(guo)測(ce)量(liang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)瞬時短路電(dian)(dian)(dian)(dian)(dian)流來估算(suan)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)內(nei)阻，進而判(pan)斷電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)量(liang)是(shi)否(fou)充(chong)足(zu)；第二種(zhong)方法是(shi)用電(dian)(dian)(dian)(dian)(dian)流表串(chuan)聯一只阻值適當的(de)電(dian)(dian)(dian)(dian)(dian)阻，通(tong)過(guo)(guo)測(ce)量(liang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流計算(suan)出電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)內(nei)阻，從而判(pan)斷電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)量(liang)是(shi)否(fou)充(chong)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MF47型萬用表(biao)(biao)對一(yi)節(jie)新2號干電(dian)(dian)池和一(yi)節(jie)舊2號干電(dian)(dian)池分別(bie)用上述(shu)兩種方法進行測試對比。假(jia)設ro是(shi)干電(dian)(dian)池內(nei)阻，RO是(shi)電(dian)(dian)流表(biao)(biao)內(nei)阻，用第二種測試方法時，RF是(shi)附加的串(chuan)聯電(dian)(dian)阻，阻值3Ω，功率2W。

      實(shi)測(ce)結果(guo)如(ru)下。新2號(hao)電(dian)(dian)(dian)池E=1.58V（用2.5V直流電(dian)(dian)(dian)壓檔測(ce)量），電(dian)(dian)(dian)壓表(biao)(biao)內(nei)阻(zu)為(wei)50kΩ，遠大于ro，故可近似認為(wei)1.58V是電(dian)(dian)(dian)池的電(dian)(dian)(dian)動勢，或稱開(kai)路電(dian)(dian)(dian)壓。用第(di)一(yi)種方法時，萬用表(biao)(biao)置5A直流電(dian)(dian)(dian)流檔，電(dian)(dian)(dian)表(biao)(biao)內(nei)阻(zu)RO=0.06Ω，測(ce)得(de)電(dian)(dian)(dian)流為(wei)3.3A。所以 ro+RO=1.58V÷3.3A≈0.48Ω，ro=0.48-0.06=0.42Ω。用第(di)二種方法時，測(ce)得(de)電(dian)(dian)(dian)流為(wei) 0.395A，RF+ro+RO=1.58V÷0.395A=4Ω，電(dian)(dian)(dian)流500mA檔內(nei)阻(zu)為(wei)0.6Ω，所以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)結果基本一(yi)致。最(zui)終(zhong)計算結果的(de)微小(xiao)差別是由于讀數(shu)誤差、電阻RF的(de)誤差以(yi)及接觸(chu)電阻等多方面因素造(zao)成的(de)，這種微小(xiao)誤差不致影(ying)響對電池(chi)電量(liang)的(de)判斷。如果被測電池(chi)的(de)容量(liang)小(xiao)、電壓高(gao)（例如15V、9V疊層電池(chi)），則應(ying)將RF的(de)阻值(zhi)適應(ying)增大。