一、一節干電池的電壓是多少伏

干電池是一種伏打電池，常用作手電筒照明、收音機等的電源，干電池電(dian)壓是干(gan)電(dian)池(chi)性能的(de)重要性能指標之(zhi)一(yi)，它(ta)表示干(gan)電(dian)池(chi)在一(yi)定狀態(tai)下電(dian)池(chi)兩端的(de)電(dian)勢差，一(yi)般(ban)干(gan)電(dian)池(chi)的(de)電(dian)壓有三(san)種(zhong)：

1、標準電壓

又(you)稱額定電(dian)(dian)壓，指(zhi)電(dian)(dian)池正(zheng)負(fu)極材料因化學反應而造(zao)成的(de)電(dian)(dian)位(wei)差(cha)，由此產生的(de)電(dian)(dian)壓值。干電(dian)(dian)池的(de)標(biao)準電(dian)(dian)壓為1.5V。

普通干電(dian)池內(nei)部的(de)化(hua)學電(dian)解液反應的(de)激(ji)烈(lie)程度只能達到使(shi)電(dian)池發揮出約1.5V的(de)電(dian)壓水平(ping)。這個(ge)電(dian)壓跟(gen)化(hua)學離子化(hua)傾(qing)向有關，也(ye)就是說跟(gen)陰極(ji)和陽極(ji)材料(liao)有關，鋅跟(gen)碳棒在電(dian)解液中(zhong)產生的(de)電(dian)勢就是大約1.5伏特。

2、開路電壓

指(zhi)電池在非工作(zuo)狀態(tai)下(xia)即(ji)電路中無(wu)電流(liu)流(liu)過時，電池正負極之間(jian)的(de)電勢差。干電池滿電時的(de)開路電壓(ya)為1.65~1.725V。

3、工作電壓

又(you)稱端電(dian)(dian)壓，是指電(dian)(dian)池(chi)(chi)在工作(zuo)(zuo)狀態(tai)下(xia)(xia)即(ji)電(dian)(dian)路中有電(dian)(dian)流(liu)流(liu)過時電(dian)(dian)池(chi)(chi)正(zheng)負極之間(jian)的電(dian)(dian)勢差(cha)。在電(dian)(dian)池(chi)(chi)放電(dian)(dian)工作(zuo)(zuo)狀態(tai)下(xia)(xia)，當電(dian)(dian)流(liu)流(liu)過電(dian)(dian)池(chi)(chi)內部(bu)時，需(xu)克服電(dian)(dian)池(chi)(chi)的內阻所(suo)造成阻力，故(gu)工作(zuo)(zuo)電(dian)(dian)壓總是低于開路電(dian)(dian)壓，充電(dian)(dian)時則與之相反。

二、怎么測量干電池的電壓

選定一個適當的(de)(de)負載電(dian)(dian)阻并聯在(zai)電(dian)(dian)池(chi)(chi)的(de)(de)正負極間，電(dian)(dian)池(chi)(chi)電(dian)(dian)壓(ya)跟剩余電(dian)(dian)量存在(zai)某(mou)種已(yi)知關系，所以(yi)根據(ju)電(dian)(dian)池(chi)(chi)的(de)(de)容量及(ji)用途(tu),再測(ce)量電(dian)(dian)阻兩端電(dian)(dian)壓(ya)，看此(ci)(ci)時電(dian)(dian)池(chi)(chi)在(zai)帶負荷時電(dian)(dian)壓(ya)較空載時下降(jiang)程度，就可以(yi)判斷電(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)量；不過前提條件是(shi)不施加(jia)任何負載的(de)(de)情況下，加(jia)負載后(hou)，電(dian)(dian)池(chi)(chi)電(dian)(dian)壓(ya)會(hui)因為(wei)內(nei)部(bu)阻抗引起壓(ya)降(jiang)失(shi)真，并隨時間的(de)(de)推移以(yi)不同速率逐(zhu)(zhu)漸(jian)降(jiang)低，并且在(zai)去除負載后(hou)逐(zhu)(zhu)漸(jian)升高。因此(ci)(ci)如果(guo)施加(jia)負載的(de)(de)話，會(hui)影(ying)響干電(dian)(dian)池(chi)(chi)電(dian)(dian)量的(de)(de)檢測(ce)結果(guo)。

萬用表(biao)(biao)也可(ke)以準確測(ce)(ce)(ce)量(liang)(liang)干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，通(tong)(tong)過測(ce)(ce)(ce)量(liang)(liang)干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)高低，對電(dian)(dian)(dian)(dian)量(liang)(liang)進行判(pan)斷，如果(guo)(guo)測(ce)(ce)(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)不(bu)小于(yu)干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)標注(zhu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)時，說明干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)量(liang)(liang)是(shi)充足(zu)的(de)(de)；小于(yu)干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)標注(zhu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)越(yue)多(duo)，說明干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)虧電(dian)(dian)(dian)(dian)越(yue)多(duo)，由于(yu)型號的(de)(de)不(bu)同干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)檢測(ce)(ce)(ce)結果(guo)(guo)會受(shou)到影響(xiang)，但(dan)是(shi)對單節干(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)來(lai)說，只要使(shi)用是(shi)普通(tong)(tong)指針式萬能表(biao)(biao)，將(jiang)萬能表(biao)(biao)選最大電(dian)(dian)(dian)(dian)流(liu)檔（0.5A-1A），負表(biao)(biao)筆接電(dian)(dian)(dian)(dian)池(chi)(chi)負極，正表(biao)(biao)筆在電(dian)(dian)(dian)(dian)池(chi)(chi)正極上迅速碰一下，注(zhu)意觀察(cha)表(biao)(biao)針運動（短路電(dian)(dian)(dian)(dian)流(liu)）情(qing)況，便知道電(dian)(dian)(dian)(dian)池(chi)(chi)還剩多(duo)少電(dian)(dian)(dian)(dian)量(liang)(liang)了。

三、干電池電壓低于多少伏就不能用了

干(gan)電池的(de)電壓(ya)會(hui)隨著使用時間(jian)的(de)增加(jia)不(bu)斷下降，下降到(dao)一(yi)定(ding)程度就(jiu)不(bu)能用了，一(yi)般(ban)情況下，干(gan)電池的(de)電壓(ya)降至1.0V ~ 1.2V時，就(jiu)可(ke)以視(shi)為干(gan)電池即(ji)將沒電，這時的(de)干(gan)電池已(yi)經不(bu)能滿足大部分(fen)電子設(she)備的(de)工作需(xu)求，需(xu)要更換干(gan)電池。