電池與充電器發熱的基本原因
電池發熱有(you)兩(liang)種(zhong)情況,一種(zhong)是(shi)放電發熱,另一種(zhong)是(shi)充(chong)電發熱。
1,放電(dian)發(fa)熱
放電(dian)(dian)(dian)發熱的原因主要有:放電(dian)(dian)(dian)過(guo)快,有可(ke)能是(shi)電(dian)(dian)(dian)池容量小,放電(dian)(dian)(dian)電(dian)(dian)(dian)流長時(shi)間超(chao)過(guo)0.5C。
1)當(dang)電(dian)動機額定(ding)電(dian)壓值低(di)(di),電(dian)池容量較小,工(gong)作(zuo)電(dian)流偏(pian)大時,電(dian)壓會(hui)急劇降(jiang)低(di)(di),容量也很快消耗,對電(dian)池最為不利。
2)電池(chi)的電化學反應速度僅(jin)能夠維(wei)持行車,經常做整循(xun)環(huan)充(chong)放電,稍不注意便(bian)會超消耗(hao)。遇到迎(ying)風上坡,耗(hao)電甚(shen)大,迫使電池(chi)極板(ban)急(ji)劇反應,電池(chi)外殼的熱度較高,會使電池(chi)受到損(sun)傷(shang),縮短壽命。
3)比較理想的是電池(chi)的電化學反應速度(du)充分(fen)地供給足夠的電能。電池(chi)的外殼沒(mei)有異常(chang)熱度(du),說明(ming)電池(chi)容量是足夠的。
2,充電發熱
充電過(guo)程中發熱,可能的故障原因(yin)有(you):
1)電池(chi)自(zi)身(shen)問題(ti),電池(chi)的(de)(de)衰老,內阻變大,電解液干涸,內部有短(duan)路等造成發熱。電池(chi)隨著使用(yong)的(de)(de)次數增(zeng)加,這(zhe)包括放電和充(chong)電,電池(chi)中(zhong)的(de)(de)水分子(zi)逐漸流失(shi),這(zhe)就是我們講的(de)(de)電池(chi)析氣、失(shi)水,從而導(dao)(dao)致(zhi)電池(chi)在(zai)電化(hua)學反(fan)應中(zhong)發熱;另(ling)外則是電池(chi)溶液在(zai)充(chong)放電過程中(zhong)形成硫酸結晶(jing)、沉淀粘糊在(zai)鉛板上,導(dao)(dao)致(zhi)電池(chi)電阻增(zeng)大而發熱;這(zhe)兩類問題(ti)可以通(tong)過加水、去(qu)硫去(qu)極等技術手(shou)段予以解決(jue)。如若電池(chi)是因短(duan)跑斷(duan)格導(dao)(dao)致(zhi)的(de)(de)電池(chi)發熱,那最好更換新電池(chi)。
2)充電器問題,一般的充電器沒(mei)(mei)有脈沖功能(neng)(neng),更沒(mei)(mei)有負脈沖消除(chu)極化功能(neng)(neng),這(zhe)(zhe)類充(chong)(chong)電(dian)(dian)器通常不(bu)能(neng)(neng)在(zai)充(chong)(chong)電(dian)(dian)后期恒壓(ya),以至造成(cheng)電(dian)(dian)池電(dian)(dian)壓(ya)超(chao)過允(yun)許(xu)值,從而導(dao)致電(dian)(dian)池大量析氣、失水(shui)、發熱(re)。 現在(zai)市(shi)場上的(de)(de)普(pu)通充(chong)(chong)電(dian)(dian)器,只(zhi)是一昧(mei)的(de)(de)恒功率充(chong)(chong)電(dian)(dian),或(huo)是對電(dian)(dian)池內部(bu)電(dian)(dian)阻(zu)等(deng)情況不(bu)能(neng)(neng)及(ji)(ji)時檢(jian)測(ce),檢(jian)測(ce)到了也不(bu)能(neng)(neng)做出(chu)及(ji)(ji)進的(de)(de)充(chong)(chong)電(dian)(dian)調整或(huo)不(bu)能(neng)(neng)給出(chu)最佳的(de)(de)充(chong)(chong)電(dian)(dian)方案,這(zhe)(zhe)些都(dou)是充(chong)(chong)電(dian)(dian)過程中導(dao)致電(dian)(dian)池發熱(re)的(de)(de)原因(yin)。
對(dui)于(yu)普通(tong)(tong)的充(chong)(chong)(chong)(chong)電(dian)(dian)器來(lai)講,可(ke)(ke)以人(ren)為(wei)地控制(zhi)溫升(sheng)(這(zhe)是某電(dian)(dian)動車(che)(che)廠家給(gei)出的方(fang)(fang)案)。方(fang)(fang)法是:在測量(liang)升(sheng)高的開始(shi)階段,及時(shi)斷開電(dian)(dian)源停止(zhi)充(chong)(chong)(chong)(chong)電(dian)(dian),溫升(sheng)和極(ji)化即自行停止(zhi),但降(jiang)低和消除極(ji)化需要時(shi)間。當溫度(du)降(jiang)低后(hou),再(zai)繼(ji)續充(chong)(chong)(chong)(chong)電(dian)(dian),之后(hou)再(zai)停充(chong)(chong)(chong)(chong),如此(ci)反(fan)復(fu),直至充(chong)(chong)(chong)(chong)滿為(wei)止(zhi)。可(ke)(ke)是這(zhe)未免太過于(yu)費神(shen)了些(xie),試問一只(zhi)普通(tong)(tong)的充(chong)(chong)(chong)(chong)電(dian)(dian)器產品,其充(chong)(chong)(chong)(chong)電(dian)(dian)時(shi)間即便(bian)是對(dui)12AH的小(xiao)(xiao)電(dian)(dian)池進行充(chong)(chong)(chong)(chong)電(dian)(dian)也需要8小(xiao)(xiao)時(shi)以上,電(dian)(dian)動車(che)(che)的用戶不(bu)可(ke)(ke)能為(wei)充(chong)(chong)(chong)(chong)足(zu)電(dian)(dian)而耗用8小(xiao)(xiao)時(shi)來(lai)不(bu)斷重復(fu)測量(liang)電(dian)(dian)池溫度(du)、斷開電(dian)(dian)源、接通(tong)(tong)電(dian)(dian)源這(zhe)些(xie)動作!因此(ci),此(ci)方(fang)(fang)法不(bu)可(ke)(ke)取。
那么,要從根(gen)本上(shang)解決因充(chong)電(dian)(dian)器問題導致的(de)電(dian)(dian)池發熱,就須正確選用充(chong)電(dian)(dian)器,電(dian)(dian)池的(de)充(chong)電(dian)(dian)過程是一個電(dian)(dian)化學反(fan)應過程,在這個過程中,電(dian)(dian)池若(ruo)出現微量發熱情(qing)況(kuang)則(ze)屬(shu)正常(chang)發熱,如若(ruo)發熱異常(chang),在電(dian)(dian)池性能良好的(de)情(qing)況(kuang)下則(ze)屬(shu)充(chong)電(dian)(dian)器原因。
如何選擇充電(dian)器呢?首(shou)先,充電(dian)器須為脈沖充電(dian)器,脈沖充電(dian)器的充電(dian)方式為:充-停-充-停……這就(jiu)讓(rang)電(dian)池在(zai)電(dian)化學反應時接(jie)受能(neng)力更(geng)好(hao),同(tong)時在(zai)停充的過程中,有(you)利(li)于電(dian)池虛高的平復。
其次(ci),選用(yong)的充電(dian)器(qi)最好具(ju)備(bei)負脈沖功能,能在充電(dian)的同時對電(dian)池起到(dao)一(yi)定的維護。
最后,不論是普通充電器還是正負脈沖充電器,它們在充電過程中的控制問題則是重中之重,即便是正負脈沖充電器,如若充電控制不精確,那也會對電池贊成傷害,目前市場上的充電器基本上有恒功、恒壓、三段式充電器、脈沖充電器,最近又推出了充電控制技術的新理念,這種充電器借鑒了很多方面的技術,我們把它稱為模糊控制技術也不為過,介于是通用討論,那在這里,我們就用通俗一點的語言來介紹它,在介紹它之前呢,我們先看看三段式充電器,什么叫三段式?就是恒流、恒壓、恒功率的充電方式,它在充電時對電池特性的對應上有一定的合理性,但它最終無法控制電池在充電過程中發熱現象的產生,因為它的充電過程是一個三步走的常規方式,孰知市場上的電池性能各異,一種常規的充電模式對一組性能參數完全對應的電池來講,無異是最佳的充電方式,但換另一組性能有所差異的電池上,則效用便完全不同了,把電池充發熱算是輕微的,充鼓電池甚至充電時電池發生爆炸都有可能!那怎么才能做到對應每一組電池都是最佳的充電模式呢?隨著單片機應用于充電器,這(zhe)(zhe)個(ge)問題便逐漸得到(dao)了解決,隨時檢測(ce)電(dian)(dian)(dian)池(chi)內(nei)部(bu)電(dian)(dian)(dian)壓內(nei)阻等情況、適時選擇相對應的(de)充電(dian)(dian)(dian)模式、非(fei)固定的(de)充電(dian)(dian)(dian)過程,這(zhe)(zhe)便是(shi)我們推崇的(de)這(zhe)(zhe)種新的(de)充電(dian)(dian)(dian)控制技術的(de)基本(ben)原理!