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，干電池電壓是干電池(chi)性能的(de)重要性能指標之(zhi)一(yi)，它(ta)表(biao)示干電池(chi)在一(yi)定狀態(tai)下電池(chi)兩端的(de)電勢差(cha)，一(yi)般(ban)干電池(chi)的(de)電壓有三種：

1、標準電壓

又稱(cheng)額(e)定(ding)電(dian)壓，指電(dian)池(chi)正負極材料因化學反應而造成(cheng)的(de)(de)電(dian)位差(cha)，由此(ci)產(chan)生的(de)(de)電(dian)壓值。干電(dian)池(chi)的(de)(de)標準電(dian)壓為(wei)1.5V。

普(pu)通(tong)干電池(chi)(chi)內部的(de)(de)化學(xue)電解液(ye)反應的(de)(de)激烈程度只能達到使(shi)電池(chi)(chi)發揮出約1.5V的(de)(de)電壓(ya)水平。這個電壓(ya)跟(gen)化學(xue)離(li)子化傾向有關(guan)，也就是說跟(gen)陰極(ji)和陽極(ji)材料有關(guan)，鋅跟(gen)碳棒在(zai)電解液(ye)中產(chan)生的(de)(de)電勢就是大(da)約1.5伏特。

2、開路電壓

指電(dian)池(chi)在非工(gong)作狀態(tai)下即電(dian)路中無電(dian)流(liu)流(liu)過時(shi)，電(dian)池(chi)正(zheng)負極(ji)之間的電(dian)勢差(cha)。干電(dian)池(chi)滿電(dian)時(shi)的開路電(dian)壓為1.65~1.725V。

3、工作電壓

又(you)稱端電(dian)(dian)(dian)(dian)壓，是(shi)指電(dian)(dian)(dian)(dian)池(chi)(chi)在工作(zuo)(zuo)狀態下即(ji)電(dian)(dian)(dian)(dian)路中(zhong)有電(dian)(dian)(dian)(dian)流流過時電(dian)(dian)(dian)(dian)池(chi)(chi)正負極之間的電(dian)(dian)(dian)(dian)勢(shi)差。在電(dian)(dian)(dian)(dian)池(chi)(chi)放電(dian)(dian)(dian)(dian)工作(zuo)(zuo)狀態下，當電(dian)(dian)(dian)(dian)流流過電(dian)(dian)(dian)(dian)池(chi)(chi)內部時，需克服電(dian)(dian)(dian)(dian)池(chi)(chi)的內阻所造成阻力(li)，故工作(zuo)(zuo)電(dian)(dian)(dian)(dian)壓總是(shi)低于開(kai)路電(dian)(dian)(dian)(dian)壓，充電(dian)(dian)(dian)(dian)時則與之相反。

二、怎么測量干電池的電壓

選定一個(ge)適當的(de)(de)(de)負(fu)(fu)載電(dian)(dian)(dian)(dian)(dian)阻(zu)并(bing)聯在(zai)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)正負(fu)(fu)極間，電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)跟(gen)剩余電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)存(cun)在(zai)某種已知關系，所以根據電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)容量(liang)(liang)(liang)及用(yong)途(tu),再測量(liang)(liang)(liang)電(dian)(dian)(dian)(dian)(dian)阻(zu)兩(liang)端電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，看此時(shi)(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)帶(dai)負(fu)(fu)荷時(shi)(shi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)較(jiao)空載時(shi)(shi)下(xia)降(jiang)程度(du)，就(jiu)可(ke)以判斷(duan)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)；不過(guo)前提條件是不施(shi)加任何(he)負(fu)(fu)載的(de)(de)(de)情況下(xia)，加負(fu)(fu)載后(hou)，電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)會因為內部阻(zu)抗引(yin)起壓(ya)(ya)降(jiang)失真，并(bing)隨時(shi)(shi)間的(de)(de)(de)推(tui)移以不同速率逐(zhu)漸(jian)降(jiang)低(di)，并(bing)且(qie)在(zai)去除負(fu)(fu)載后(hou)逐(zhu)漸(jian)升高。因此如果施(shi)加負(fu)(fu)載的(de)(de)(de)話(hua)，會影響干電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)的(de)(de)(de)檢測結果。

萬(wan)用(yong)(yong)表(biao)(biao)(biao)也可以(yi)準(zhun)確測(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)壓，通(tong)過測(ce)量(liang)干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)壓的(de)(de)高低(di)，對電(dian)(dian)(dian)(dian)量(liang)進行判斷，如果測(ce)量(liang)電(dian)(dian)(dian)(dian)壓不小于(yu)干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)標注電(dian)(dian)(dian)(dian)壓時，說(shuo)明干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)量(liang)是(shi)充足(zu)的(de)(de)；小于(yu)干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)標注電(dian)(dian)(dian)(dian)壓越(yue)多，說(shuo)明干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)虧電(dian)(dian)(dian)(dian)越(yue)多，由于(yu)型(xing)號(hao)的(de)(de)不同干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)檢測(ce)結(jie)果會受到(dao)影響，但(dan)是(shi)對單節(jie)干(gan)(gan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)來(lai)說(shuo)，只要使(shi)用(yong)(yong)是(shi)普通(tong)指針式(shi)萬(wan)能(neng)表(biao)(biao)(biao)，將萬(wan)能(neng)表(biao)(biao)(biao)選最大電(dian)(dian)(dian)(dian)流(liu)檔（0.5A-1A），負(fu)(fu)表(biao)(biao)(biao)筆接電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)負(fu)(fu)極，正(zheng)表(biao)(biao)(biao)筆在電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)正(zheng)極上迅速(su)碰一下，注意觀察表(biao)(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)(chi)(chi)還剩多少電(dian)(dian)(dian)(dian)量(liang)了。

三、干電池電壓低于多少伏就不能用了

干(gan)(gan)電池(chi)(chi)的電壓會隨著使用(yong)時(shi)間(jian)的增加不(bu)斷(duan)下降(jiang)，下降(jiang)到一定(ding)程度就不(bu)能(neng)用(yong)了，一般情況下，干(gan)(gan)電池(chi)(chi)的電壓降(jiang)至1.0V ~ 1.2V時(shi)，就可以視(shi)為干(gan)(gan)電池(chi)(chi)即將沒電，這時(shi)的干(gan)(gan)電池(chi)(chi)已經不(bu)能(neng)滿足大部分電子設(she)備的工作需求，需要更換干(gan)(gan)電池(chi)(chi)。