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，干電池電壓是干(gan)電池性能的重要(yao)性能指(zhi)標之一，它表示干(gan)電池在(zai)一定(ding)狀態下電池兩(liang)端的電勢差，一般干(gan)電池的電壓有三(san)種：

1、標準電壓

又稱(cheng)額定電(dian)(dian)壓(ya)，指電(dian)(dian)池正(zheng)負極材料因化(hua)學反應而造成的(de)電(dian)(dian)位差，由此產生的(de)電(dian)(dian)壓(ya)值。干電(dian)(dian)池的(de)標準電(dian)(dian)壓(ya)為(wei)1.5V。

普通干電(dian)(dian)(dian)池(chi)內(nei)部的化學電(dian)(dian)(dian)解液反應的激(ji)烈程(cheng)度只能達到使電(dian)(dian)(dian)池(chi)發揮出約1.5V的電(dian)(dian)(dian)壓水平(ping)。這個電(dian)(dian)(dian)壓跟化學離子(zi)化傾向有(you)關，也就(jiu)是說跟陰極和(he)陽極材料(liao)有(you)關，鋅跟碳棒在電(dian)(dian)(dian)解液中產生的電(dian)(dian)(dian)勢(shi)就(jiu)是大約1.5伏特。

2、開路電壓

指電(dian)(dian)(dian)(dian)池在非工作(zuo)狀態下即電(dian)(dian)(dian)(dian)路中無電(dian)(dian)(dian)(dian)流流過時(shi)，電(dian)(dian)(dian)(dian)池正負極之(zhi)間的(de)電(dian)(dian)(dian)(dian)勢(shi)差(cha)。干(gan)電(dian)(dian)(dian)(dian)池滿電(dian)(dian)(dian)(dian)時(shi)的(de)開路電(dian)(dian)(dian)(dian)壓(ya)為1.65~1.725V。

3、工作電壓

又稱(cheng)端電(dian)(dian)(dian)壓，是指電(dian)(dian)(dian)池(chi)在工作狀(zhuang)態(tai)下(xia)即(ji)電(dian)(dian)(dian)路中有電(dian)(dian)(dian)流(liu)流(liu)過時(shi)電(dian)(dian)(dian)池(chi)正負(fu)極之(zhi)間的電(dian)(dian)(dian)勢(shi)差。在電(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)工作狀(zhuang)態(tai)下(xia)，當電(dian)(dian)(dian)流(liu)流(liu)過電(dian)(dian)(dian)池(chi)內部(bu)時(shi)，需克服電(dian)(dian)(dian)池(chi)的內阻所造成阻力，故工作電(dian)(dian)(dian)壓總是低于(yu)開路電(dian)(dian)(dian)壓，充電(dian)(dian)(dian)時(shi)則(ze)與(yu)之(zhi)相(xiang)反。

二、怎么測量干電池的電壓

選定一個(ge)適當的(de)(de)負(fu)載(zai)電(dian)(dian)(dian)(dian)(dian)(dian)阻并(bing)聯在電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)正(zheng)負(fu)極間，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)跟剩余電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)存在某種已知關(guan)系，所(suo)以根據(ju)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)容量(liang)(liang)及(ji)用途(tu),再(zai)測(ce)(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)(dian)(dian)阻兩(liang)端電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，看(kan)此(ci)(ci)時電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在帶負(fu)荷時電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)較空(kong)載(zai)時下(xia)降程(cheng)度，就可以判斷電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)；不(bu)(bu)(bu)過前提條件是不(bu)(bu)(bu)施加(jia)任何負(fu)載(zai)的(de)(de)情況下(xia)，加(jia)負(fu)載(zai)后，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)會因為內(nei)部阻抗引起壓(ya)(ya)降失真(zhen)，并(bing)隨時間的(de)(de)推(tui)移以不(bu)(bu)(bu)同速率逐漸降低，并(bing)且在去除負(fu)載(zai)后逐漸升高。因此(ci)(ci)如果施加(jia)負(fu)載(zai)的(de)(de)話(hua)，會影響(xiang)干電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)的(de)(de)檢測(ce)(ce)結(jie)果。

萬用表(biao)也(ye)可以準確(que)測(ce)(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)(dian)池的電(dian)(dian)(dian)(dian)壓(ya)，通(tong)過測(ce)(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)的高低，對電(dian)(dian)(dian)(dian)量(liang)進行(xing)判(pan)斷，如果(guo)測(ce)(ce)量(liang)電(dian)(dian)(dian)(dian)壓(ya)不(bu)小于(yu)(yu)干(gan)(gan)電(dian)(dian)(dian)(dian)池的標(biao)注電(dian)(dian)(dian)(dian)壓(ya)時，說(shuo)明干(gan)(gan)電(dian)(dian)(dian)(dian)池的電(dian)(dian)(dian)(dian)量(liang)是充足的；小于(yu)(yu)干(gan)(gan)電(dian)(dian)(dian)(dian)池的標(biao)注電(dian)(dian)(dian)(dian)壓(ya)越多(duo)(duo)，說(shuo)明干(gan)(gan)電(dian)(dian)(dian)(dian)池虧電(dian)(dian)(dian)(dian)越多(duo)(duo)，由于(yu)(yu)型號(hao)的不(bu)同(tong)干(gan)(gan)電(dian)(dian)(dian)(dian)池的檢測(ce)(ce)結(jie)果(guo)會受到影(ying)響，但是對單節干(gan)(gan)電(dian)(dian)(dian)(dian)池來(lai)說(shuo)，只要使用是普(pu)通(tong)指針(zhen)式萬能(neng)表(biao)，將萬能(neng)表(biao)選最大電(dian)(dian)(dian)(dian)流檔（0.5A-1A），負(fu)表(biao)筆(bi)(bi)接(jie)電(dian)(dian)(dian)(dian)池負(fu)極，正表(biao)筆(bi)(bi)在電(dian)(dian)(dian)(dian)池正極上(shang)迅速碰一下，注意觀察表(biao)針(zhen)運動（短路電(dian)(dian)(dian)(dian)流）情況，便知(zhi)道電(dian)(dian)(dian)(dian)池還剩多(duo)(duo)少電(dian)(dian)(dian)(dian)量(liang)了。

三、干電池電壓低于多少伏就不能用了

干電(dian)池(chi)的(de)(de)電(dian)壓會隨(sui)著(zhu)使(shi)用(yong)時間的(de)(de)增加不斷下(xia)(xia)降，下(xia)(xia)降到一(yi)定(ding)程(cheng)度(du)就不能用(yong)了，一(yi)般情況下(xia)(xia)，干電(dian)池(chi)的(de)(de)電(dian)壓降至1.0V ~ 1.2V時，就可以視為(wei)干電(dian)池(chi)即將沒電(dian)，這時的(de)(de)干電(dian)池(chi)已經不能滿足大部分(fen)電(dian)子設備的(de)(de)工(gong)作需求(qiu)，需要更換(huan)干電(dian)池(chi)。