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)壓(ya)是干電(dian)(dian)池(chi)(chi)性(xing)能(neng)的(de)(de)重要性(xing)能(neng)指標之一，它表示(shi)干電(dian)(dian)池(chi)(chi)在一定狀態下電(dian)(dian)池(chi)(chi)兩端的(de)(de)電(dian)(dian)勢差，一般(ban)干電(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)壓(ya)有(you)三(san)種：

1、標準電壓

又(you)稱(cheng)額定電(dian)(dian)壓(ya)，指電(dian)(dian)池正(zheng)負(fu)極材料因化學反應而造成的電(dian)(dian)位差，由(you)此產(chan)生的電(dian)(dian)壓(ya)值。干電(dian)(dian)池的標準電(dian)(dian)壓(ya)為1.5V。

普通干電(dian)池內部的化學(xue)電(dian)解(jie)液(ye)(ye)反應的激烈(lie)程度只能達到使電(dian)池發(fa)揮出(chu)約1.5V的電(dian)壓(ya)水(shui)平。這個電(dian)壓(ya)跟(gen)化學(xue)離子(zi)化傾向有(you)關，也就是說跟(gen)陰極和陽(yang)極材料有(you)關，鋅(xin)跟(gen)碳(tan)棒(bang)在電(dian)解(jie)液(ye)(ye)中產生(sheng)的電(dian)勢就是大(da)約1.5伏特。

2、開路電壓

指電(dian)(dian)池在非工作狀態下即電(dian)(dian)路中無電(dian)(dian)流(liu)流(liu)過時，電(dian)(dian)池正負極之間的電(dian)(dian)勢差。干電(dian)(dian)池滿電(dian)(dian)時的開(kai)路電(dian)(dian)壓為1.65~1.725V。

3、工作電壓

又稱端電(dian)(dian)(dian)壓，是指電(dian)(dian)(dian)池(chi)在工(gong)作狀態下(xia)(xia)即電(dian)(dian)(dian)路中有電(dian)(dian)(dian)流(liu)流(liu)過時電(dian)(dian)(dian)池(chi)正負極之間的電(dian)(dian)(dian)勢差。在電(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)工(gong)作狀態下(xia)(xia)，當電(dian)(dian)(dian)流(liu)流(liu)過電(dian)(dian)(dian)池(chi)內部時，需克服電(dian)(dian)(dian)池(chi)的內阻所造(zao)成阻力，故工(gong)作電(dian)(dian)(dian)壓總是低于開路電(dian)(dian)(dian)壓，充電(dian)(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)(de)(de)負載電(dian)(dian)阻并聯在(zai)電(dian)(dian)池(chi)的(de)(de)(de)(de)正負極間(jian)，電(dian)(dian)池(chi)電(dian)(dian)壓(ya)(ya)跟剩余電(dian)(dian)量(liang)(liang)存在(zai)某(mou)種(zhong)已知關(guan)系(xi)，所以(yi)根據電(dian)(dian)池(chi)的(de)(de)(de)(de)容量(liang)(liang)及用途(tu),再測量(liang)(liang)電(dian)(dian)阻兩(liang)端(duan)電(dian)(dian)壓(ya)(ya)，看(kan)此時(shi)電(dian)(dian)池(chi)在(zai)帶負荷時(shi)電(dian)(dian)壓(ya)(ya)較空載時(shi)下(xia)降(jiang)程度，就可以(yi)判(pan)斷(duan)電(dian)(dian)池(chi)的(de)(de)(de)(de)電(dian)(dian)量(liang)(liang)；不過前提條(tiao)件是不施加(jia)任何(he)負載的(de)(de)(de)(de)情況下(xia)，加(jia)負載后，電(dian)(dian)池(chi)電(dian)(dian)壓(ya)(ya)會因(yin)為(wei)內部阻抗引起壓(ya)(ya)降(jiang)失(shi)真，并隨時(shi)間(jian)的(de)(de)(de)(de)推移以(yi)不同速率逐漸(jian)降(jiang)低，并且在(zai)去除負載后逐漸(jian)升高。因(yin)此如果施加(jia)負載的(de)(de)(de)(de)話，會影響干(gan)電(dian)(dian)池(chi)電(dian)(dian)量(liang)(liang)的(de)(de)(de)(de)檢測結果。

萬(wan)用表(biao)(biao)也可以(yi)準確測(ce)(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)壓(ya)，通(tong)過測(ce)(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)的高低，對(dui)電(dian)(dian)(dian)量(liang)進行判(pan)斷(duan)，如果(guo)測(ce)(ce)量(liang)電(dian)(dian)(dian)壓(ya)不(bu)小于(yu)干(gan)(gan)電(dian)(dian)(dian)池(chi)的標(biao)(biao)注電(dian)(dian)(dian)壓(ya)時，說明干(gan)(gan)電(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)量(liang)是充足的；小于(yu)干(gan)(gan)電(dian)(dian)(dian)池(chi)的標(biao)(biao)注電(dian)(dian)(dian)壓(ya)越多，說明干(gan)(gan)電(dian)(dian)(dian)池(chi)虧電(dian)(dian)(dian)越多，由(you)于(yu)型號的不(bu)同干(gan)(gan)電(dian)(dian)(dian)池(chi)的檢測(ce)(ce)結果(guo)會受到影響，但是對(dui)單(dan)節干(gan)(gan)電(dian)(dian)(dian)池(chi)來說，只(zhi)要使用是普通(tong)指針式萬(wan)能表(biao)(biao)，將(jiang)萬(wan)能表(biao)(biao)選最大電(dian)(dian)(dian)流(liu)檔(dang)（0.5A-1A），負(fu)表(biao)(biao)筆(bi)接電(dian)(dian)(dian)池(chi)負(fu)極，正表(biao)(biao)筆(bi)在電(dian)(dian)(dian)池(chi)正極上迅速碰一(yi)下(xia)，注意(yi)觀(guan)察(cha)表(biao)(biao)針運動（短路(lu)電(dian)(dian)(dian)流(liu)）情況，便知道電(dian)(dian)(dian)池(chi)還剩多少電(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)(dian)池(chi)(chi)的電(dian)(dian)壓會隨著使用時(shi)間(jian)的增加不(bu)斷(duan)下降，下降到一(yi)定程度(du)就不(bu)能(neng)用了，一(yi)般(ban)情況下，干電(dian)(dian)池(chi)(chi)的電(dian)(dian)壓降至1.0V ~ 1.2V時(shi)，就可以視(shi)為干電(dian)(dian)池(chi)(chi)即將沒電(dian)(dian)，這時(shi)的干電(dian)(dian)池(chi)(chi)已(yi)經不(bu)能(neng)滿足大部(bu)分(fen)電(dian)(dian)子設備(bei)的工作(zuo)需求(qiu)，需要更(geng)換干電(dian)(dian)池(chi)(chi)。