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)壓是干(gan)電(dian)(dian)池(chi)性能的重要性能指標之(zhi)一，它表示(shi)干(gan)電(dian)(dian)池(chi)在一定(ding)狀(zhuang)態下電(dian)(dian)池(chi)兩端的電(dian)(dian)勢差，一般干(gan)電(dian)(dian)池(chi)的電(dian)(dian)壓有三(san)種：

1、標準電壓

又(you)稱額定(ding)電(dian)壓，指電(dian)池(chi)正負極材(cai)料因化(hua)學反應而造成的(de)電(dian)位差，由此產(chan)生的(de)電(dian)壓值(zhi)。干電(dian)池(chi)的(de)標準電(dian)壓為(wei)1.5V。

普(pu)通干電(dian)池內(nei)部的化(hua)學電(dian)解液反應(ying)的激烈程度只能達到使電(dian)池發揮出約1.5V的電(dian)壓(ya)(ya)水平。這個電(dian)壓(ya)(ya)跟化(hua)學離子化(hua)傾向(xiang)有(you)關，也就是說跟陰(yin)極(ji)和陽極(ji)材料有(you)關，鋅跟碳棒在電(dian)解液中(zhong)產生(sheng)的電(dian)勢(shi)就是大約1.5伏特。

2、開路電壓

指電(dian)池在非工作狀(zhuang)態下即電(dian)路(lu)中(zhong)無電(dian)流(liu)流(liu)過時，電(dian)池正負極之(zhi)間(jian)的(de)電(dian)勢(shi)差。干電(dian)池滿電(dian)時的(de)開路(lu)電(dian)壓為1.65~1.725V。

3、工作電壓

又稱端電(dian)(dian)壓(ya)，是指電(dian)(dian)池(chi)在(zai)工作(zuo)狀態下即電(dian)(dian)路(lu)中有電(dian)(dian)流(liu)流(liu)過時(shi)電(dian)(dian)池(chi)正負極之間的電(dian)(dian)勢差。在(zai)電(dian)(dian)池(chi)放電(dian)(dian)工作(zuo)狀態下，當電(dian)(dian)流(liu)流(liu)過電(dian)(dian)池(chi)內部(bu)時(shi)，需(xu)克服電(dian)(dian)池(chi)的內阻(zu)所(suo)造成(cheng)阻(zu)力，故(gu)工作(zuo)電(dian)(dian)壓(ya)總(zong)是低于開路(lu)電(dian)(dian)壓(ya)，充電(dian)(dian)時(shi)則與之相反。

二、怎么測量干電池的電壓

選定一個適當(dang)的(de)(de)負(fu)(fu)載(zai)(zai)電(dian)(dian)阻(zu)并(bing)聯(lian)在電(dian)(dian)池(chi)(chi)的(de)(de)正負(fu)(fu)極間，電(dian)(dian)池(chi)(chi)電(dian)(dian)壓跟剩余電(dian)(dian)量(liang)(liang)存在某(mou)種已知關系，所以(yi)根據電(dian)(dian)池(chi)(chi)的(de)(de)容量(liang)(liang)及用途,再測量(liang)(liang)電(dian)(dian)阻(zu)兩(liang)端電(dian)(dian)壓，看此(ci)時電(dian)(dian)池(chi)(chi)在帶負(fu)(fu)荷時電(dian)(dian)壓較空載(zai)(zai)時下(xia)降程度，就可以(yi)判(pan)斷電(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)量(liang)(liang)；不(bu)過前提條件是不(bu)施加任何(he)負(fu)(fu)載(zai)(zai)的(de)(de)情(qing)況下(xia)，加負(fu)(fu)載(zai)(zai)后，電(dian)(dian)池(chi)(chi)電(dian)(dian)壓會因為內(nei)部阻(zu)抗引(yin)起壓降失真(zhen)，并(bing)隨時間的(de)(de)推移以(yi)不(bu)同速率逐漸(jian)(jian)降低(di)，并(bing)且在去除負(fu)(fu)載(zai)(zai)后逐漸(jian)(jian)升高(gao)。因此(ci)如果(guo)施加負(fu)(fu)載(zai)(zai)的(de)(de)話，會影響干電(dian)(dian)池(chi)(chi)電(dian)(dian)量(liang)(liang)的(de)(de)檢測結(jie)果(guo)。

萬(wan)用表(biao)(biao)(biao)也可(ke)以準確(que)測(ce)量干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)的(de)電(dian)壓(ya)(ya)，通(tong)過測(ce)量干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)電(dian)壓(ya)(ya)的(de)高低，對電(dian)量進行判斷，如果測(ce)量電(dian)壓(ya)(ya)不小于干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)的(de)標注電(dian)壓(ya)(ya)時(shi)，說明(ming)干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)的(de)電(dian)量是充足的(de)；小于干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)的(de)標注電(dian)壓(ya)(ya)越(yue)多，說明(ming)干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)虧電(dian)越(yue)多，由于型號的(de)不同干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)的(de)檢測(ce)結果會受(shou)到影響，但是對單節干(gan)(gan)(gan)電(dian)池(chi)(chi)(chi)(chi)來說，只要使用是普通(tong)指針(zhen)式萬(wan)能表(biao)(biao)(biao)，將萬(wan)能表(biao)(biao)(biao)選最(zui)大電(dian)流(liu)檔(dang)（0.5A-1A），負表(biao)(biao)(biao)筆(bi)接電(dian)池(chi)(chi)(chi)(chi)負極，正表(biao)(biao)(biao)筆(bi)在(zai)電(dian)池(chi)(chi)(chi)(chi)正極上(shang)迅速(su)碰一下，注意觀察表(biao)(biao)(biao)針(zhen)運動（短路電(dian)流(liu)）情況，便(bian)知(zhi)道電(dian)池(chi)(chi)(chi)(chi)還剩多少電(dian)量了。

三、干電池電壓低于多少伏就不能用了

干(gan)電(dian)(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)(dian)壓(ya)會隨著使(shi)用時(shi)間(jian)的增加不(bu)斷下降(jiang)(jiang)(jiang)，下降(jiang)(jiang)(jiang)到一(yi)定程度(du)就不(bu)能用了，一(yi)般情況下，干(gan)電(dian)(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)(dian)壓(ya)降(jiang)(jiang)(jiang)至(zhi)1.0V ~ 1.2V時(shi)，就可以視為干(gan)電(dian)(dian)(dian)(dian)池(chi)即(ji)將(jiang)沒電(dian)(dian)(dian)(dian)，這時(shi)的干(gan)電(dian)(dian)(dian)(dian)池(chi)已經不(bu)能滿足大部分電(dian)(dian)(dian)(dian)子設(she)備的工作需(xu)求，需(xu)要更換干(gan)電(dian)(dian)(dian)(dian)池(chi)。