二次可充電電池在充電過程常用充電方式及控制方法
電池的(de)充電過程通(tong)常可分為預(yu)充電、快速充電、補足充電、涓流充電四個階段。
對長(chang)期不用(yong)的或(huo)新(xin)電(dian)池(chi)充(chong)電(dian)時(shi),一(yi)開始就采用(yong)快速充(chong)電(dian),會影響電(dian)池(chi)的壽命。因此,這(zhe)種電(dian)池(chi)應先用(yong)小電(dian)流充(chong)電(dian),使其滿(man)足一(yi)定(ding)的充(chong)電(dian)條(tiao)件,這(zhe)個階段稱為預充(chong)電(dian)。
快速(su)充(chong)電(dian)(dian)(dian)就是用大(da)電(dian)(dian)(dian)流(liu)充(chong)電(dian)(dian)(dian),迅速(su)恢(hui)復電(dian)(dian)(dian)池電(dian)(dian)(dian)能。快速(su)充(chong)電(dian)(dian)(dian)速(su)率一般在1C以(yi)上,快速(su)充(chong)時間(jian)由電(dian)(dian)(dian)池容量和充(chong)電(dian)(dian)(dian)速(su)率決定(ding)。
為了避免過充電,一些充電器采用小電流充電。鎳鎘電池正常充電時,可以接受C/10或更低的充電速率,這樣充電時間要10h以上。采用小電流充電,電池內不會產生過多的氣體,電池溫度也不會過高。只要電池接到充電器上,低速率恒流充電器就能對電池提供很小(xiao)的(de)涓流充電電流。電池采用小(xiao)電流充電時(shi),電池內產(chan)生(sheng)的(de)熱量可以自然散去。
涓流充(chong)(chong)(chong)電(dian)器的主要問(wen)題是充(chong)(chong)(chong)電(dian)速度太慢,例如,容量(liang)為(wei)1Ah的電(dian)池(chi),采用C/10充(chong)(chong)(chong)電(dian)速率(lv)時,充(chong)(chong)(chong)電(dian)時間要10h以上(shang)。此外,電(dian)池(chi)采用低(di)充(chong)(chong)(chong)電(dian)速率(lv)反(fan)復充(chong)(chong)(chong)電(dian)時,還會產(chan)生枝晶。大部分涓流充(chong)(chong)(chong)電(dian)器中,都沒有任何電(dian)壓或溫(wen)度反(fan)饋控制,因而不(bu)能保證電(dian)池(chi)充(chong)(chong)(chong)足電(dian)后(hou),立即關(guan)斷充(chong)(chong)(chong)電(dian)器。
快速充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)分(fen)恒流(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和脈(mo)(mo)沖(chong)(chong)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)兩種,恒流(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)就是(shi)(shi)以(yi)恒定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian),脈(mo)(mo)沖(chong)(chong)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)則是(shi)(shi)首(shou)先用脈(mo)(mo)沖(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。然(ran)后讓(rang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian),如此循環。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池脈(mo)(mo)沖(chong)(chong)的(de)幅(fu)(fu)值(zhi)(zhi)很大、寬度很窄(zhai)。通常放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)脈(mo)(mo)沖(chong)(chong)的(de)幅(fu)(fu)值(zhi)(zhi)為充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)脈(mo)(mo)沖(chong)(chong)的(de)3倍(bei)左右(you)。雖然(ran)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)脈(mo)(mo)沖(chong)(chong)的(de)幅(fu)(fu)值(zhi)(zhi)與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池容量有關(guan),但是(shi)(shi),與充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)幅(fu)(fu)值(zhi)(zhi)的(de)比值(zhi)(zhi)保持不變,脈(mo)(mo)沖(chong)(chong)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時,充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)波形。
充(chong)(chong)(chong)電(dian)過(guo)(guo)程(cheng)中,鎳鎘(ge)電(dian)池(chi)(chi)中的(de)(de)(de)氫氧化(hua)鎳還原(yuan)(yuan)為(wei)氫氧化(hua)亞鎳,氫氧化(hua)鎘(ge)還原(yuan)(yuan)為(wei)鎘(ge)。在這(zhe)個(ge)過(guo)(guo)程(cheng)中產(chan)生的(de)(de)(de)氣(qi)泡,聚集(ji)在極(ji)板(ban)(ban)兩邊,這(zhe)樣就會減小(xiao)極(ji)板(ban)(ban)的(de)(de)(de)有效(xiao)面積,使極(ji)板(ban)(ban)的(de)(de)(de)內(nei)(nei)阻增大。由于極(ji)板(ban)(ban)的(de)(de)(de)有效(xiao)面積變小(xiao),充(chong)(chong)(chong)入(ru)全部電(dian)量(liang)所需的(de)(de)(de)時間增加。 加入(ru)放(fang)電(dian)脈沖后,氣(qi)泡離開極(ji)板(ban)(ban)并與負(fu)極(ji)板(ban)(ban)上的(de)(de)(de)氧復合。這(zhe)個(ge)去極(ji)化(hua)過(guo)(guo)程(cheng)減小(xiao)了電(dian)池(chi)(chi)的(de)(de)(de)內(nei)(nei)部壓力、溫度和(he)內(nei)(nei)阻。同時,充(chong)(chong)(chong)入(ru)電(dian)池(chi)(chi)的(de)(de)(de)大部分(fen)電(dian)荷都轉換為(wei)化(hua)學能(neng),而不會轉變為(wei)氣(qi)體和(he)熱量(liang)。 充(chong)(chong)(chong)放(fang)電(dian)脈沖寬度的(de)(de)(de)選擇(ze)應能(neng)保證極(ji)板(ban)(ban)恢(hui)復原(yuan)(yuan)來的(de)(de)(de)晶體結構,從而消除記憶效(xiao)應。采用(yong)放(fang)電(dian)去極(ji)化(hua)措施(shi)后,可以提高充(chong)(chong)(chong)電(dian)效(xiao)率并且(qie)允許大電(dian)流快速充(chong)(chong)(chong)電(dian)。
采用某些快速充電止法時,快速充電終止后,電池并未充足電。為了保證充入100%的電量,還應加入補足充電過程。補足充電速率一般不超過0.3C。在補足充電過程中,溫度會繼續上升,當溫度超過規定的極限時,充電器轉入涓流充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態。 存放(fang)時(shi),鎳鎘電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)電(dian)(dian)(dian)(dian)(dian)量(liang)將按C/30到C/50的(de)放(fang)電(dian)(dian)(dian)(dian)(dian)速(su)率(lv)減小,為了補償電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)因(yin)自放(fang)電(dian)(dian)(dian)(dian)(dian)而損失的(de)電(dian)(dian)(dian)(dian)(dian)量(liang),補足充(chong)電(dian)(dian)(dian)(dian)(dian)結(jie)束(shu)后,充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)應自動轉入涓流電(dian)(dian)(dian)(dian)(dian)過程。涓流充(chong)電(dian)(dian)(dian)(dian)(dian)也(ye)稱(cheng)為維(wei)護充(chong)電(dian)(dian)(dian)(dian)(dian)。根(gen)據電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)自放(fang)電(dian)(dian)(dian)(dian)(dian)特性,涓流充(chong)電(dian)(dian)(dian)(dian)(dian)速(su)率(lv)一般都很低。只要(yao)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)接在充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)上并且充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)接通電(dian)(dian)(dian)(dian)(dian)源,在維(wei)護充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態下,充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)將以某一充(chong)電(dian)(dian)(dian)(dian)(dian)速(su)率(lv)給電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)補充(chong)電(dian)(dian)(dian)(dian)(dian)荷,這(zhe)樣可使電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)總處于(yu)充(chong)足電(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態。
快速充電終止控(kong)制方法
采(cai)用快速(su)充(chong)電(dian)(dian)法時(shi),充(chong)電(dian)(dian)電(dian)(dian)流(liu)為常規充(chong)電(dian)(dian)電(dian)(dian)流(liu)的(de)(de)幾(ji)十倍(bei)。充(chong)足電(dian)(dian)后,如果(guo)不(bu)及時(shi)停止快速(su)充(chong)電(dian)(dian),電(dian)(dian)池(chi)的(de)(de)溫度和(he)(he)內(nei)部(bu)壓力將迅速(su)上(shang)(shang)升。內(nei)部(bu)壓力過大時(shi),密封電(dian)(dian)池(chi)將打開放(fang)氣孔,從(cong)而(er)使電(dian)(dian)解液(ye)逸散,造成電(dian)(dian)解液(ye)的(de)(de)粘稠性增(zeng)(zeng)大,電(dian)(dian)池(chi)的(de)(de)內(nei)阻增(zeng)(zeng)大,容量(liang)下降。 從(cong)鎳鎘電(dian)(dian)池(chi)快速(su)充(chong)電(dian)(dian)特性可以看出,充(chong)足電(dian)(dian)后,電(dian)(dian)池(chi)電(dian)(dian)壓開始下降,電(dian)(dian)池(chi)的(de)(de)溫度和(he)(he)內(nei)部(bu)壓力迅速(su)上(shang)(shang)升,為了保證電(dian)(dian)池(chi)充(chong)足電(dian)(dian)又不(bu)過充(chong)電(dian)(dian),可以采(cai)用定(ding)時(shi)控制、電(dian)(dian)壓控制和(he)(he)溫度控制待多(duo)種方法。
(1)定(ding)(ding)時(shi)控制 采(cai)用1.25C充電(dian)(dian)速率時(shi),電(dian)(dian)池(chi)1h可充足;采(cai)用2.5C充電(dian)(dian)速率時(shi),30min可充足。因此,根據(ju)電(dian)(dian)池(chi)的(de)容(rong)量和充電(dian)(dian)電(dian)(dian)流,很容(rong)易確定(ding)(ding)所需的(de)充電(dian)(dian)時(shi)間(jian)。這種控制方法(fa)最簡單,但是由于(yu)電(dian)(dian)池(chi)的(de)起始充電(dian)(dian)狀態不完全相同,有的(de)電(dian)(dian)池(chi)充不足,有的(de)電(dian)(dian)池(chi)過充電(dian)(dian),因此,只有充電(dian)(dian)速率小于(yu)0.3C時(shi),才允許采(cai)用這種方法(fa)。
(2)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)控制(zhi)(zhi)(zhi) 在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)控制(zhi)(zhi)(zhi)法(fa)(fa)中,最容(rong)易檢測(ce)的(de)(de)是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)(de)最高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。常用(yong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)控制(zhi)(zhi)(zhi)法(fa)(fa)有: 最高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(Vmax) 從(cong)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)特性(xing)曲線可(ke)以(yi)看出(chu),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達到(dao)最大(da)值(zhi)時(shi),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)即(ji)(ji)充(chong)(chong)足(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)程中,當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達到(dao)規(gui)定值(zhi)后,應立(li)即(ji)(ji)停(ting)止快(kuai)(kuai)(kuai)速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。這(zhe)種控制(zhi)(zhi)(zhi)方法(fa)(fa)的(de)(de)缺(que)(que)點(dian)(dian)(dian)是:電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充(chong)(chong)足(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)最高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)隨環(huan)境溫(wen)度、充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)率而變,而且電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)組(zu)中各單體電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)(de)最高充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)也有差別,因(yin)此(ci)采用(yong)這(zhe)種方法(fa)(fa)不可(ke)能非常準確地判斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)已(yi)足(zu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)負增(zeng)(zeng)量(liang)(-ΔV) 由于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)負增(zeng)(zeng)量(liang)與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)組(zu)的(de)(de)絕對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)無關,而且不受環(huan)境溫(wen)度和(he)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)率等因(yin)素影響,因(yin)此(ci)可(ke)以(yi)比(bi)較準確地判斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)已(yi)充(chong)(chong)足(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。這(zhe)種控制(zhi)(zhi)(zhi)方法(fa)(fa)的(de)(de)缺(que)(que)點(dian)(dian)(dian)是:電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)出(chu)現(xian)負增(zeng)(zeng)量(liang)后,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)已(yi)經(jing)過(guo)(guo)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian),因(yin)此(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)(de)溫(wen)度較高。此(ci)外(wai)鎳氫(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充(chong)(chong)足(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)后,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)要經(jing)過(guo)(guo)較長時(shi)間(jian),才出(chu)現(xian)負增(zeng)(zeng)量(liang),過(guo)(guo)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)較嚴(yan)重。因(yin)此(ci),這(zhe)種控制(zhi)(zhi)(zhi)方法(fa)(fa)主(zhu)要適用(yong)于鎳鎘電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)。 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)零增(zeng)(zeng)量(liang)(0ΔV) 鎳氫(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器中,為了避免等待出(chu)現(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)負增(zeng)(zeng)量(liang)的(de)(de)時(shi)間(jian)過(guo)(guo)久(jiu)而損壞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi),通常采用(yong)0ΔV控制(zhi)(zhi)(zhi)法(fa)(fa)。這(zhe)種方法(fa)(fa)的(de)(de)缺(que)(que)點(dian)(dian)(dian)是:充(chong)(chong)足(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)以(yi)前(qian),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)在某一段(duan)時(shi)間(jian)內可(ke)能變化很(hen)小,從(cong)而造成過(guo)(guo)早(zao)地停(ting)止快(kuai)(kuai)(kuai)速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。為此(ci),目前(qian)大(da)多數鎳氫(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)快(kuai)(kuai)(kuai)速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器都采用(yong)高靈敏-0ΔV檢測(ce),當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)略有降低時(shi),立(li)即(ji)(ji)停(ting)止快(kuai)(kuai)(kuai)速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。
(3)溫(wen)(wen)(wen)度(du)(du)(du)控(kong)制(zhi) 為了避(bi)免損壞電(dian)(dian)(dian)(dian)池(chi)(chi)(chi),電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)過低時(shi)(shi)不(bu)能(neng)開始快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian),電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)上(shang)(shang)升(sheng)(sheng)(sheng)(sheng)到(dao)規(gui)定數值后(hou)(hou),必(bi)須立(li)即(ji)停止快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian)。常用(yong)(yong)(yong)的(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)(du)控(kong)制(zhi)方(fang)(fang)法(fa)(fa)有(you)(you): 最高溫(wen)(wen)(wen)度(du)(du)(du)(Tmax) 充(chong)電(dian)(dian)(dian)(dian)過程中(zhong),通常當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)達(da)到(dao)45℃時(shi)(shi),應立(li)即(ji)停止快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian)。電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)(du)可通過與(yu)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)裝在一(yi)(yi)起的(de)(de)(de)熱(re)敏電(dian)(dian)(dian)(dian)阻(zu)來檢測。這(zhe)種(zhong)方(fang)(fang)法(fa)(fa)的(de)(de)(de)缺點是熱(re)敏電(dian)(dian)(dian)(dian)阻(zu)的(de)(de)(de)響應時(shi)(shi)間較長,溫(wen)(wen)(wen)度(du)(du)(du)檢測有(you)(you)一(yi)(yi)定滯(zhi)后(hou)(hou),同時(shi)(shi),電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)最高工作溫(wen)(wen)(wen)度(du)(du)(du)與(yu)環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)有(you)(you)關。當(dang)環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)過低時(shi)(shi),充(chong)足電(dian)(dian)(dian)(dian)后(hou)(hou),電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)(du)也(ye)達(da)不(bu)到(dao)45℃。 溫(wen)(wen)(wen)升(sheng)(sheng)(sheng)(sheng)(ΔT) 為了消(xiao)除環(huan)境(jing)影響,可采(cai)用(yong)(yong)(yong)溫(wen)(wen)(wen)升(sheng)(sheng)(sheng)(sheng)控(kong)制(zhi)法(fa)(fa)。當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)溫(wen)(wen)(wen)升(sheng)(sheng)(sheng)(sheng)達(da)到(dao)規(gui)定值后(hou)(hou),立(li)即(ji)停止快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian)。為了實現溫(wen)(wen)(wen)升(sheng)(sheng)(sheng)(sheng)控(kong)制(zhi),必(bi)須用(yong)(yong)(yong)兩只熱(re)敏電(dian)(dian)(dian)(dian)阻(zu),分別檢測電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)和環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)。 溫(wen)(wen)(wen)度(du)(du)(du)變化(hua)率(lv)(ΔT/Δt) 鎳(nie)氫和鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)足電(dian)(dian)(dian)(dian)后(hou)(hou),電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)迅速(su)(su)(su)(su)(su)(su)上(shang)(shang)升(sheng)(sheng)(sheng)(sheng),而且(qie)上(shang)(shang)升(sheng)(sheng)(sheng)(sheng)速(su)(su)(su)(su)(su)(su)率(lv)ΔT/Δt基(ji)本相同,當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)每分鐘上(shang)(shang)升(sheng)(sheng)(sheng)(sheng)1℃時(shi)(shi),應當(dang)立(li)即(ji)終止快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian),這(zhe)種(zhong)充(chong)電(dian)(dian)(dian)(dian)控(kong)制(zhi)方(fang)(fang)法(fa)(fa),近年(nian)來被(bei)普遍(bian)采(cai)用(yong)(yong)(yong)。應當(dang)說明,由(you)于(yu)熱(re)敏電(dian)(dian)(dian)(dian)阻(zu)的(de)(de)(de)阻(zu)值與(yu)溫(wen)(wen)(wen)度(du)(du)(du)關系是非(fei)線(xian)性的(de)(de)(de),因此,為了提高檢測精度(du)(du)(du)應設法(fa)(fa)減小熱(re)敏電(dian)(dian)(dian)(dian)阻(zu)非(fei)線(xian)性的(de)(de)(de)影響。 最低溫(wen)(wen)(wen)度(du)(du)(du)(Tmin) 當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫(wen)(wen)(wen)度(du)(du)(du)低于(yu)10℃時(shi)(shi),采(cai)用(yong)(yong)(yong)大電(dian)(dian)(dian)(dian)流快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian),會影響電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)壽命。在這(zhe)種(zhong)情況下,充(chong)電(dian)(dian)(dian)(dian)器應自動轉入涓流充(chong)電(dian)(dian)(dian)(dian),待電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)(du)上(shang)(shang)升(sheng)(sheng)(sheng)(sheng)到(dao)10℃后(hou)(hou),再轉入快(kuai)速(su)(su)(su)(su)(su)(su)充(chong)電(dian)(dian)(dian)(dian)。
(4)綜合控制 述各種控制方法各有優缺點。為了保證在任何情況下,均能準確可*地控制電池的充電狀態,目前快速充電器中通常采(cai)用包括定時控(kong)制(zhi)、電壓控(kong)制(zhi)和溫度控(kong)制(zhi)的綜合控(kong)制(zhi)法。
