檢測普通鋅錳干(gan)電(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)量是否(fou)(fou)(fou)充足(zu)，通常有兩種方法(fa)。第(di)一種方法(fa)是通過(guo)測量電(dian)(dian)(dian)池(chi)瞬(shun)時短路電(dian)(dian)(dian)流來(lai)估算(suan)電(dian)(dian)(dian)池(chi)的(de)(de)內(nei)阻(zu)，進(jin)而判斷(duan)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)量是否(fou)(fou)(fou)充足(zu)；第(di)二種方法(fa)是用(yong)電(dian)(dian)(dian)流表串聯(lian)一只阻(zu)值適當的(de)(de)電(dian)(dian)(dian)阻(zu)，通過(guo)測量電(dian)(dian)(dian)池(chi)的(de)(de)放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流計算(suan)出電(dian)(dian)(dian)池(chi)內(nei)阻(zu)，從而判斷(duan)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)量是否(fou)(fou)(fou)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MF47型(xing)萬用表對(dui)一節新(xin)2號(hao)干(gan)電(dian)(dian)池和一節舊2號(hao)干(gan)電(dian)(dian)池分別用上述兩(liang)種方(fang)法進行(xing)測(ce)試(shi)對(dui)比(bi)。假設ro是干(gan)電(dian)(dian)池內阻(zu)，RO是電(dian)(dian)流表內阻(zu)，用第二種測(ce)試(shi)方(fang)法時，RF是附加的串聯(lian)電(dian)(dian)阻(zu)，阻(zu)值3Ω，功率2W。

      實測結果如下。新2號(hao)電(dian)(dian)(dian)池E=1.58V（用2.5V直(zhi)流電(dian)(dian)(dian)壓檔測量），電(dian)(dian)(dian)壓表(biao)內阻(zu)為(wei)(wei)50kΩ，遠大于ro，故可近似認為(wei)(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。用第一種方法(fa)時，萬(wan)用表(biao)置5A直(zhi)流電(dian)(dian)(dian)流檔，電(dian)(dian)(dian)表(biao)內阻(zu)RO=0.06Ω，測得(de)電(dian)(dian)(dian)流為(wei)(wei)3.3A。所(suo)以 ro+RO=1.58V÷3.3A≈0.48Ω，ro=0.48-0.06=0.42Ω。用第二(er)種方法(fa)時，測得(de)電(dian)(dian)(dian)流為(wei)(wei) 0.395A，RF+ro+RO=1.58V÷0.395A=4Ω，電(dian)(dian)(dian)流500mA檔內阻(zu)為(wei)(wei)0.6Ω，所(suo)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(zhong)測(ce)試方法的(de)(de)(de)結果(guo)(guo)基本一致。最終計算(suan)結果(guo)(guo)的(de)(de)(de)微(wei)小(xiao)差(cha)別(bie)是由(you)于讀(du)數誤差(cha)、電(dian)(dian)阻(zu)RF的(de)(de)(de)誤差(cha)以及接(jie)觸電(dian)(dian)阻(zu)等(deng)多方面(mian)因(yin)素造成的(de)(de)(de)，這種(zhong)微(wei)小(xiao)誤差(cha)不致影響對(dui)電(dian)(dian)池(chi)電(dian)(dian)量(liang)的(de)(de)(de)判斷。如(ru)(ru)果(guo)(guo)被(bei)測(ce)電(dian)(dian)池(chi)的(de)(de)(de)容量(liang)小(xiao)、電(dian)(dian)壓高（例如(ru)(ru)15V、9V疊(die)層電(dian)(dian)池(chi)），則(ze)應將RF的(de)(de)(de)阻(zu)值適應增(zeng)大。