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)(dian)(dian)壓是干電(dian)(dian)(dian)池(chi)(chi)性能的重(zhong)要性能指標之一，它表示干電(dian)(dian)(dian)池(chi)(chi)在一定狀態下電(dian)(dian)(dian)池(chi)(chi)兩端的電(dian)(dian)(dian)勢差，一般干電(dian)(dian)(dian)池(chi)(chi)的電(dian)(dian)(dian)壓有三種：

1、標準電壓

又稱額定電(dian)(dian)(dian)壓，指電(dian)(dian)(dian)池正負極材料因化學反(fan)應而(er)造(zao)成的電(dian)(dian)(dian)位差，由此產生的電(dian)(dian)(dian)壓值。干(gan)電(dian)(dian)(dian)池的標(biao)準電(dian)(dian)(dian)壓為1.5V。

普通干電池內部的化學(xue)電解液反(fan)應的激烈程(cheng)度只能達到使(shi)電池發(fa)揮(hui)出約1.5V的電壓水平。這個電壓跟化學(xue)離(li)子化傾向有關，也就(jiu)是說跟陰極和陽極材(cai)料有關，鋅(xin)跟碳棒在電解液中產生(sheng)的電勢就(jiu)是大(da)約1.5伏特。

2、開路電壓

指電(dian)池在(zai)非工作狀(zhuang)態下即電(dian)路(lu)中(zhong)無電(dian)流流過時，電(dian)池正(zheng)負極(ji)之(zhi)間的電(dian)勢差(cha)。干(gan)電(dian)池滿電(dian)時的開路(lu)電(dian)壓為1.65~1.725V。

3、工作電壓

又稱端(duan)電(dian)(dian)壓，是指電(dian)(dian)池在(zai)工(gong)作(zuo)(zuo)狀態下即電(dian)(dian)路(lu)中有電(dian)(dian)流(liu)流(liu)過(guo)時(shi)電(dian)(dian)池正負(fu)極之(zhi)(zhi)間的(de)電(dian)(dian)勢差(cha)。在(zai)電(dian)(dian)池放電(dian)(dian)工(gong)作(zuo)(zuo)狀態下，當電(dian)(dian)流(liu)流(liu)過(guo)電(dian)(dian)池內(nei)(nei)部時(shi)，需克服電(dian)(dian)池的(de)內(nei)(nei)阻所造成阻力，故工(gong)作(zuo)(zuo)電(dian)(dian)壓總是低于開(kai)路(lu)電(dian)(dian)壓，充電(dian)(dian)時(shi)則(ze)與之(zhi)(zhi)相反。

二、怎么測量干電池的電壓

選定一個(ge)適當的(de)(de)負(fu)(fu)載(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)并聯在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)正(zheng)負(fu)(fu)極間(jian)(jian)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)跟剩余電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量存(cun)在(zai)(zai)某(mou)種已知關系(xi)，所以根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)容量及(ji)用途,再測(ce)量電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)兩端電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，看此時(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)(zai)帶負(fu)(fu)荷時(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)較空載(zai)時(shi)下降程度(du)，就可以判斷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量；不(bu)(bu)過前提(ti)條件是不(bu)(bu)施(shi)加任何負(fu)(fu)載(zai)的(de)(de)情況下，加負(fu)(fu)載(zai)后(hou)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)會(hui)因為內部阻(zu)抗引起壓(ya)(ya)降失真(zhen)，并隨時(shi)間(jian)(jian)的(de)(de)推移以不(bu)(bu)同(tong)速率逐(zhu)漸降低，并且在(zai)(zai)去除負(fu)(fu)載(zai)后(hou)逐(zhu)漸升高。因此如果施(shi)加負(fu)(fu)載(zai)的(de)(de)話，會(hui)影(ying)響干電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量的(de)(de)檢測(ce)結果。

萬用表(biao)(biao)(biao)也可以(yi)準確測(ce)量干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的電(dian)(dian)(dian)(dian)(dian)壓(ya)，通過測(ce)量干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)的高低，對電(dian)(dian)(dian)(dian)(dian)量進(jin)行判斷，如果(guo)測(ce)量電(dian)(dian)(dian)(dian)(dian)壓(ya)不(bu)小(xiao)于(yu)干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的標(biao)注(zhu)電(dian)(dian)(dian)(dian)(dian)壓(ya)時，說明(ming)干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的電(dian)(dian)(dian)(dian)(dian)量是充足的；小(xiao)于(yu)干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的標(biao)注(zhu)電(dian)(dian)(dian)(dian)(dian)壓(ya)越(yue)多，說明(ming)干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)虧電(dian)(dian)(dian)(dian)(dian)越(yue)多，由于(yu)型(xing)號的不(bu)同干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的檢測(ce)結果(guo)會受(shou)到影響，但是對單節干電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)來說，只要(yao)使用是普通指針(zhen)式萬能(neng)表(biao)(biao)(biao)，將萬能(neng)表(biao)(biao)(biao)選最大電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)檔（0.5A-1A），負表(biao)(biao)(biao)筆接電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)負極(ji)，正表(biao)(biao)(biao)筆在電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)正極(ji)上迅速碰一(yi)下(xia)，注(zhu)意觀察表(biao)(biao)(biao)針(zhen)運動（短路電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)）情(qing)況，便知道(dao)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)還剩多少電(dian)(dian)(dian)(dian)(dian)量了。

三、干電池電壓低于多少伏就不能用了

干電池(chi)(chi)的(de)(de)電壓會隨著使用時間的(de)(de)增加不斷下降，下降到一定(ding)程度就(jiu)不能(neng)用了，一般情況下，干電池(chi)(chi)的(de)(de)電壓降至(zhi)1.0V ~ 1.2V時，就(jiu)可以(yi)視為干電池(chi)(chi)即將沒電，這時的(de)(de)干電池(chi)(chi)已經不能(neng)滿足(zu)大(da)部分電子(zi)設(she)備的(de)(de)工作(zuo)需求，需要更(geng)換干電池(chi)(chi)。