蓄電池容量能有效使用的往往都會比理論值要低，這是為什么呢？下面從幾方面來了解一下影響蓄電池放電容量大小的因素都有哪些？

1、蓄電池的電壓

電(dian)(dian)(dian)動勢（電(dian)(dian)(dian)壓）是(shi)指電(dian)(dian)(dian)池(chi)在開路時(shi)，正(zheng)極(ji)平衡電(dian)(dian)(dian)極(ji)電(dian)(dian)(dian)勢與負極(ji)平衡電(dian)(dian)(dian)極(ji)電(dian)(dian)(dian)勢之差，其大(da)小(xiao)取決于電(dian)(dian)(dian)池(chi)中的(de)化學(xue)(xue)反應，與電(dian)(dian)(dian)池(chi)的(de)形狀、尺(chi)寸無關。根據(ju)鉛酸(suan)蓄電(dian)(dian)(dian)池(chi)的(de)成流反應，按熱力學(xue)(xue)原則(ze)，電(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)動勢為：

其(qi)中E為(wei)(wei)(wei)(wei)(wei)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)動勢；Ee為(wei)(wei)(wei)(wei)(wei)所有反應(ying)物的(de)(de)活度(du)(du)或(huo)壓力等于1時的(de)(de)電(dian)(dian)(dian)動勢，稱為(wei)(wei)(wei)(wei)(wei)標準電(dian)(dian)(dian)動勢（V）；R為(wei)(wei)(wei)(wei)(wei)摩(mo)爾(er)氣(qi)體常數，為(wei)(wei)(wei)(wei)(wei)8.31J/（K穖ol）；T為(wei)(wei)(wei)(wei)(wei)絕對溫度(du)(du)（K）；F為(wei)(wei)(wei)(wei)(wei)法(fa)拉第常數（96500C/mol）；n為(wei)(wei)(wei)(wei)(wei)電(dian)(dian)(dian)化學(xue)反應(ying)中的(de)(de)電(dian)(dian)(dian)子(zi)得(de)失數目。電(dian)(dian)(dian)動勢是電(dian)(dian)(dian)池(chi)(chi)在(zai)理論上輸(shu)(shu)出(chu)能(neng)(neng)量大小的(de)(de)量度(du)(du)之一，如果其(qi)它條件(jian)相同，電(dian)(dian)(dian)動勢越高的(de)(de)電(dian)(dian)(dian)池(chi)(chi)，理論上能(neng)(neng)輸(shu)(shu)出(chu)的(de)(de)能(neng)(neng)量就越大。

2、蓄電池的溫度

蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)內(nei)部(bu)溫度(du)(du)(du)對其性能(neng)影(ying)響(xiang)很大(da)，對鉛酸(suan)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)而言，更是如此，因為在充放電(dian)(dian)(dian)過程(cheng)中其內(nei)部(bu)存在“氧循環”，產生的(de)額外(wai)熱量(liang)(liang)會使溫度(du)(du)(du)上(shang)(shang)升，因而影(ying)響(xiang)更大(da)，因此在判斷蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)性能(neng)時(shi)，要充分考慮溫度(du)(du)(du)的(de)影(ying)響(xiang)。當(dang)溫度(du)(du)(du)上(shang)(shang)升時(shi)，電(dian)(dian)(dian)解(jie)液的(de)運(yun)動(dong)(dong)速(su)度(du)(du)(du)增(zeng)(zeng)(zeng)(zeng)大(da)，獲得動(dong)(dong)能(neng)增(zeng)(zeng)(zeng)(zeng)加，因此滲透(tou)力加強(qiang)，電(dian)(dian)(dian)解(jie)液電(dian)(dian)(dian)阻(zu)減小，電(dian)(dian)(dian)化學(xue)反應增(zeng)(zeng)(zeng)(zeng)強(qiang)，這些都使蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)容量(liang)(liang)增(zeng)(zeng)(zeng)(zeng)大(da)。當(dang)溫度(du)(du)(du)降(jiang)(jiang)低(di)時(shi)，電(dian)(dian)(dian)解(jie)液的(de)粘度(du)(du)(du)增(zeng)(zeng)(zeng)(zeng)大(da)，使離(li)子運(yun)動(dong)(dong)受到(dao)較(jiao)大(da)阻(zu)力，擴散能(neng)力降(jiang)(jiang)低(di)，滲入極板內(nei)部(bu)困(kun)難，活性物質(zhi)深處(chu)由于酸(suan)的(de)缺乏而得不到(dao)充分利(li)用，導致容量(liang)(liang)下降(jiang)(jiang)。其次(ci)是電(dian)(dian)(dian)解(jie)液電(dian)(dian)(dian)阻(zu)隨溫度(du)(du)(du)下降(jiang)(jiang)而增(zeng)(zeng)(zeng)(zeng)加，結果電(dian)(dian)(dian)池(chi)(chi)(chi)內(nei)阻(zu)增(zeng)(zeng)(zeng)(zeng)加，電(dian)(dian)(dian)壓(ya)降(jiang)(jiang)增(zeng)(zeng)(zeng)(zeng)大(da)，從而容量(liang)(liang)下降(jiang)(jiang)。溫度(du)(du)(du)變化1℃時(shi)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)容量(liang)(liang)的(de)變化量(liang)(liang)稱為容量(liang)(liang)的(de)溫度(du)(du)(du)系數。

3、放電電流

隨著放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流的(de)加大，蓄電(dian)(dian)(dian)池的(de)容量(liang)(liang)(liang)和端電(dian)(dian)(dian)壓(ya)將(jiang)隨之減(jian)小。這是因為放(fang)電(dian)(dian)(dian)時(shi)，正負極板(ban)的(de)PbO2，Pb都轉變為PbSO4，由于PbSO4比重較小，因此(ci)隨著PbSO4的(de)析出，極板(ban)孔(kong)隙(xi)(xi)(xi)逐(zhu)漸縮(suo)小，使(shi)容器(qi)中的(de)硫酸(suan)滲入困(kun)難，且(qie)當放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流增大時(shi)，化學(xue)反(fan)應速(su)度加快(kuai)，PbSO4堵塞孔(kong)隙(xi)(xi)(xi)的(de)速(su)度也(ye)加快(kuai)。由于孔(kong)隙(xi)(xi)(xi)中電(dian)(dian)(dian)解(jie)液(ye)濃度迅(xun)速(su)下(xia)降，使(shi)極板(ban)內部的(de)大量(liang)(liang)(liang)活(huo)性物(wu)質不能參與化學(xue)反(fan)應，蓄電(dian)(dian)(dian)池的(de)實際輸出容量(liang)(liang)(liang)減(jian)小。

4、電解液濃度

在(zai)鉛酸蓄(xu)電(dian)(dian)(dian)池(chi)中，H2SO4也是(shi)(shi)反應(ying)物，體積(ji)一定時(shi)，增(zeng)(zeng)加電(dian)(dian)(dian)解(jie)液(ye)的(de)(de)(de)濃(nong)(nong)度(du)就是(shi)(shi)增(zeng)(zeng)加反應(ying)物質，所(suo)以(yi)在(zai)實際使用的(de)(de)(de)電(dian)(dian)(dian)解(jie)液(ye)濃(nong)(nong)度(du)范圍內，隨(sui)著電(dian)(dian)(dian)解(jie)液(ye)濃(nong)(nong)度(du)的(de)(de)(de)增(zeng)(zeng)加，電(dian)(dian)(dian)池(chi)容(rong)(rong)(rong)量(liang)(liang)(liang)也增(zeng)(zeng)加，特別是(shi)(shi)在(zai)高(gao)倍率(lv)(lv)放(fang)電(dian)(dian)(dian)并(bing)由正極板限(xian)制電(dian)(dian)(dian)池(chi)容(rong)(rong)(rong)量(liang)(liang)(liang)時(shi)更是(shi)(shi)如此。額(e)定容(rong)(rong)(rong)量(liang)(liang)(liang)也叫(jiao)保證(zheng)容(rong)(rong)(rong)量(liang)(liang)(liang)，是(shi)(shi)按國(guo)家(jia)或有關部門頒布的(de)(de)(de)標(biao)準，保證(zheng)電(dian)(dian)(dian)池(chi)在(zai)一定的(de)(de)(de)放(fang)電(dian)(dian)(dian)條(tiao)件(jian)下(xia)，應(ying)該放(fang)出(chu)的(de)(de)(de)最低限(xian)度(du)的(de)(de)(de)容(rong)(rong)(rong)量(liang)(liang)(liang)值(zhi)。一般常指在(zai)溫度(du)20℃～25℃時(shi)，充滿其容(rong)(rong)(rong)量(liang)(liang)(liang)，并(bing)擱置(zhi)24小時(shi)后，以(yi)10小時(shi)放(fang)電(dian)(dian)(dian)率(lv)(lv)或0.1C電(dian)(dian)(dian)流(liu)數值(zhi)的(de)(de)(de)電(dian)(dian)(dian)流(liu)放(fang)電(dian)(dian)(dian)至其終止電(dian)(dian)(dian)壓（1.75V~1.8V/單體，2V蓄(xu)電(dian)(dian)(dian)池(chi)）時(shi)所(suo)輸出(chu)的(de)(de)(de)容(rong)(rong)(rong)量(liang)(liang)(liang)。當蓄(xu)電(dian)(dian)(dian)池(chi)以(yi)恒(heng)定電(dian)(dian)(dian)流(liu)放(fang)電(dian)(dian)(dian)時(shi)，它(ta)的(de)(de)(de)容(rong)(rong)(rong)量(liang)(liang)(liang)（Ah）等于放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)（A）與(yu)其持續時(shi)間（h）的(de)(de)(de)乘積(ji)。C=It（2.9如果放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)不是(shi)(shi)常數，那么蓄(xu)電(dian)(dian)(dian)池(chi)的(de)(de)(de)輸出(chu)容(rong)(rong)(rong)量(liang)(liang)(liang)為不同的(de)(de)(de)放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)與(yu)其持續時(shi)間的(de)(de)(de)乘積(ji)之和。