如何為您的電池組設計出優秀的電池充電器方案

 

 在可充電池化學電池或物理電池的運用過程中，充電器是其成功運用的重要裝置， 所以可充電池一出世，充電器便是個關鍵問題，因為充電器的好壞直接影響到電池的兩個重要技術指標：可充電池的使用容量；可充電 池的循環使用次數，即使用壽命。然而直到六十年代以前，充電器技術并沒有得到長足發展，普遍采用的方法主要是恒流或恒壓充電方法， 充電效果不是太理想。這種狀況直到六十年代基于最低出氣率可充曲線原理發現電池可接受充電電流大小隨時間按指數規律下降這一規律后， 才證實恒流或恒壓充電均不是最適合的方法。因為恒流充電時，其起始充電電流總是低于電池的可接受能力，造成充電效率低，充電時間長， 而在充電后期，最終的充電電流又總是高于電池可接受的程度，因而電池內部氣體析出率不斷增加，到充電結束時，所有充電電流全部供給氣 體析出，電池內部電壓迅速增加，電池溫度也隨之迅速上升，造成每次充電電極上都有活性物質脫落，從而大大降低了電池的壽命，而恒壓 充電(dian)(dian)方法在充電(dian)(dian)初期電(dian)(dian)池內阻極(ji)低致使充電(dian)(dian)電(dian)(dian)流過(guo)大，而隨時間并不按指數規(gui)律下降常(chang)偏(pian)離(li)制定曲線

 

根據充電曲線研究實驗，又提出了所謂的兩段式、三段式或更多段式充電。所謂兩段式充電指首先對電池進行恒流或恒壓充電，當電池電壓達到 一定程度，然后對電池進行涓流充電：所謂三段式一般是首先對電池進行恒流充是，待電池電壓達到電壓閥值后轉化為第二階段，即所謂限壓充 電階段，當充電電流小到某種程度后轉化為第三階段．即所謂限壓充電。另外，由于實際運用的需要，往往還希望對電池進行快速充電．影響充 電器快速充電還有兩個重要因素：一是極化電壓：二是記憶效應，其中極化電壓是在充電過程中，電荷堆積于電池電極上而產生的反問電壓，實 際上表現為對電池內阻的增加上，消除它的有效方法是采用負脈沖方法在電池兩端瞬間放電去除電極上堆積的電荷．并由此產生了脈沖充電方法： 記憶效應并不是所有電池都有，可以通過多次的充放電即可消除。上述兩種效應應該在充電控制器設計中予以重視。

 

實際上，充電控制器在近年采取得了長足的發展，一個明顯的標志就是世界上大多數的半導體廠商大都出品了自己的充電器芯片，有的還帶有 中央處理器 (即CPU)。 盡管已經有了多種充電方法，而且也有一定的效果，然而大多忽略了一個重要事實，即充電電池并不是工作于理想狀態， 每個電池都有自己獨特的個性．確切地說每個充電電池都有自己有別干其它甚至是同類電池的充放電曲線，該曲線甚至在充電過程中還足動態變 化的，這就意味著好的充電控制模式應該是變化的，而且應該與電池的充放電曲線變化一致才是最佳的。事實上，每個電池在充電的任意時(shi)刻總 存(cun)在一個(ge)最佳的充(chong)電電流(liu)和充(chong)電模式的，問題是我(wo)們如何才能逼近這個(ge)最佳值(zhi)。 

綜(zong)合起來，判斷規則有如下幾種：

●定時控制；

●電(dian)壓(ya)(ya)控(kong)制(含最(zui)高(gao)電(dian)壓(ya)(ya)：電(dian)壓(ya)(ya)負增量：電(dian)壓(ya)(ya)零(ling)增量等)；

●溫(wen)度控制(包括最(zui)(zui)高溫(wen)度，最(zui)(zui)高溫(wen)升：溫(wen)度變化率等)；

●電流控制等。

較好的辦法是采(cai)用綜合判斷方法，對(dui)每個(ge)指(zhi)標進行跟蹤，并按(an)模糊數學(xue)原理分別記分，按(an)照置(zhi)信度做出最佳判斷。 電池快速充電分為幾個(ge)階段,見(jian)本文(wen)所述(shu)及(ji)通用充電器(qi)運行簡(jian)圖.[圖1]

　

 

圖1.通用電池充電器(qi)充電參數圖表.

 

起始階段

起(qi)(qi)始(shi)階段(duan)(duan)(duan)在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)中雖不(bu)屬于真正起(qi)(qi)作用的(de)(de)那幾個(ge)(ge)階段(duan)(duan)(duan),但在(zai)整個(ge)(ge)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)中,起(qi)(qi)始(shi)階段(duan)(duan)(duan)仍是一(yi)個(ge)(ge)非常(chang)重(zhong)要(yao)的(de)(de)滿足條件. 充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器啟(qi)動(dong)以后開(kai)始(shi)自測(ce),如(ru)電(dian)(dian)(dian)(dian)(dian)(dian)源出現(xian)(xian)(xian)故障(zhang)或(huo)反復(fu)起(qi)(qi)動(dong),充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)就會被打斷.如(ru)果(guo)缺乏相應智能或(huo)時(shi)間關斷裝置(zhi)以及電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)密 封性能不(bu)能得到改善,那么此種現(xian)(xian)(xian)象往往會被忽視.幾乎所有的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)源出現(xian)(xian)(xian)故障(zhang)以后都可以完全(quan)重(zhong)新啟(qi)動(dong),但如(ru)過(guo)充(chong)(chong)(chong)不(bu) 被允許,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器要(yao)能夠進行特(te)別的(de)(de)自測(ce)程(cheng)(cheng)序以判斷電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)是否早已(yi)充(chong)(chong)(chong)滿.電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)狀態要(yao)顯(xian)現(xian)(xian)(xian)在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器指示燈或(huo)類似(si)的(de)(de)顯(xian)示裝置(zhi)上. （不(bu)好的(de)(de)案例(li)：例(li)如(ru)只(zhi)靠定時(shi)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器,用四個(ge)(ge)小(xiao)時(shi)間隔的(de)(de)固(gu)定時(shi)間給電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian).如(ru)果(guo)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)三小(xiao)時(shi)59分鐘(zhong),電(dian)(dian)(dian)(dian)(dian)(dian)源出現(xian)(xian)(xian)故障(zhang)斷電(dian)(dian)(dian)(dian)(dian)(dian), 當故障(zhang)清除重(zhong)新送(song)電(dian)(dian)(dian)(dian)(dian)(dian)以后,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器又會開(kai)始(shi)重(zhong)新一(yi)輪的(de)(de)四小(xiao)時(shi)固(gu)定充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian),從(cong)而(er)造成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)過(guo)充(chong)(chong)(chong)四個(ge)(ge)小(xiao)時(shi).這種結果(guo)往往會對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi) 造成(cheng)損(sun)壞。因此原因,定時(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器很少(shao)被采用。）

充電時可充電池應備條件

當電(dian)(dian)(dian)(dian)池(chi)連接上充電(dian)(dian)(dian)(dian)器(qi)(qi)以(yi)后,此充電(dian)(dian)(dian)(dian)階(jie)段之充電(dian)(dian)(dian)(dian)器(qi)(qi)要(yao)能夠(gou)有(you)所感(gan)應(ying)顯示以(yi)及彼電(dian)(dian)(dian)(dian)池(chi)是否(fou)可以(yi)進行充電(dian)(dian)(dian)(dian).一般當充電(dian)(dian)(dian)(dian)器(qi)(qi)電(dian)(dian)(dian)(dian)源關(guan)斷(duan) 的(de)情況下(xia),此電(dian)(dian)(dian)(dian)池(chi)感(gan)應(ying)裝置(zhi)通(tong)常(chang)根據(ju)(ju)充電(dian)(dian)(dian)(dian)器(qi)(qi)接頭的(de)端口電(dian)(dian)(dian)(dian)壓來(lai)進行判斷(duan),但當電(dian)(dian)(dian)(dian)池(chi)已(yi)經(jing)反復過度使用或端口電(dian)(dian)(dian)(dian)壓極低的(de)情況下(xia), 這(zhe)種(zhong)(zhong)感(gan)應(ying)裝置(zhi)往往會(hui)產生(sheng)問(wen)題.作為一種(zhong)(zhong)替代(dai)方法,充電(dian)(dian)(dian)(dian)器(qi)(qi)經(jing)常(chang)根據(ju)(ju)溫度或電(dian)(dian)(dian)(dian)壓瞬時跳變來(lai)達到(dao)上述目的(de).這(zhe)種(zhong)(zhong)硬(ying)件設(she)置(zhi)同樣適 用于(yu)電(dian)(dian)(dian)(dian)池(chi)組.

一(yi)旦充(chong)(chong)電(dian)(dian)器感應連接到了可充(chong)(chong)電(dian)(dian)電(dian)(dian)池,它還必須判斷出(chu)(chu)電(dian)(dian)池是否(fou)具備良好可充(chong)(chong)條(tiao)件.在這個(ge)次級(ji)階段(duan)[限定(ding)條(tiao)件],電(dian)(dian)池要(yao)能夠 被檢測出(chu)(chu)其基本功能狀態;開路(lu),短(duan)路(lu),高溫或是低溫.以此來檢測電(dian)(dian)池是否(fou)具備可充(chong)(chong)性,一(yi)些鉛酸(suan)(suan)充(chong)(chong)電(dian)(dian)器類(lei)型特(te)別需要(yao)一(yi)個(ge)可通(tong)過(guo)(guo) LED燈來顯示(shi)出(chu)(chu)其充(chong)(chong)電(dian)(dian)的(de)(de)主充(chong)(chong)電(dian)(dian)流[大約以五分(fen)之一(yi)的(de)(de)快(kuai)充(chong)(chong)額定(ding)電(dian)(dian)流],并(bing)允許電(dian)(dian)池在一(yi)固定(ding)充(chong)(chong)電(dian)(dian)時間段(duan)內達到其特(te)定(ding)的(de)(de)電(dian)(dian)池電(dian)(dian)壓. 這種技術對已(yi)經(jing)反復過(guo)(guo)度使用的(de)(de)鉛酸(suan)(suan)[PbSO4]蓄電(dian)(dian)池,應避免出(chu)(chu)現反接的(de)(de)問題.

對(dui)外圍設備和電(dian)(dian)(dian)池(chi)溫(wen)度的(de)(de)檢測也是本階段(duan)必要條件之一(yi).當充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)檢測到電(dian)(dian)(dian)池(chi)的(de)(de)溫(wen)度過高(gao)或(huo)過低,一(yi)般會(hui)等(deng)待(dai)一(yi)段(duan)預先設定的(de)(de) 時間以使其恢(hui)復正常.如(ru)在設定時間內并(bing)未恢(hui)復正常,充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)會(hui)自(zi)動(dong)改變充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu),這個動(dong)作相(xiang)(xiang)應(ying)就調整了電(dian)(dian)(dian)池(chi)溫(wen)度,所(suo)(suo)以充(chong)(chong)(chong)電(dian)(dian)(dian)效(xiao)率(lv) 會(hui)大大增加.最后(hou),充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)需要檢測一(yi)下與電(dian)(dian)(dian)池(chi)的(de)(de)連接狀態是開(kai)路(lu)抑或(huo)短路(lu).通(tong)常開(kai)路(lu)狀態容(rong)易檢測,而一(yi)旦出(chu)現短路(lu)顯示,就需要進 一(yi)步確認,以避免造成事(shi)故(gu)的(de)(de)發(fa)生.如(ru)果(guo)所(suo)(suo)有檢測都獲得通(tong)過,就可(ke)以給電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)了.這種設置相(xiang)(xiang)當領先,請參閱附圖1

預先充電條件設置[自選類型]

有一(yi)些充(chong)電(dian)(dian)(dian)(dian)(dian)器[如早期(qi)出現的(de)(de)鎳鎘電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)]都設(she)計(ji)有一(yi)個充(chong)電(dian)(dian)(dian)(dian)(dian)前期(qi)預測階段,用(yong)以(yi)判斷在重(zhong)新(xin)充(chong)電(dian)(dian)(dian)(dian)(dian)前，待測電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是(shi)否已‘完全’放(fang)(fang)電(dian)(dian)(dian)(dian)(dian). 所謂‘完全’放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)系指每節電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)端口電(dian)(dian)(dian)(dian)(dian)壓放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)到1V的(de)(de)水平,以(yi)去除電(dian)(dian)(dian)(dian)(dian)解液中的(de)(de)枝(zhi)(zhi)狀(zhuang)結構(gou),這也是(shi)人們(men)為(wei)什么經常(chang)(chang)錯誤(wu)地理解‘記憶(yi) 效應’的(de)(de)原(yuan)因(yin)[通常(chang)(chang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)一(yi)次(ci)可(ke)充(chong)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量是(shi)上(shang)次(ci)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量的(de)(de)104—110百分比].這種所謂的(de)(de)‘記憶(yi)效應’特指電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)內(nei)部電(dian)(dian)(dian)(dian)(dian)解液枝(zhi)(zhi)狀(zhuang)結 構(gou)狀(zhuang)態的(de)(de)自我恢復(fu)能力,如受(shou)到破壞,將減少(shao)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)使用(yong)壽命.所以(yi)按正(zheng)常(chang)(chang)時(shi)間(jian)周期(qi)進行的(de)(de)充(chong)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian),往往會解決這個問題.

在每(mei)次充(chong)電前(qian),此預(yu)測(ce)(ce)(ce)階(jie)段(duan)都(dou)會被(bei)自動完成,或在電池(chi)充(chong)電剩余過半顯示(shi)[通過連接測(ce)(ce)(ce)試或其(qi)它操(cao)作]之后.預(yu)測(ce)(ce)(ce)階(jie)段(duan)一般從一到十小 時不(bu)(bu)等.在一小時之內(nei)放(fang)空電池(chi)通常不(bu)(bu)予考慮.而通過連接電阻縮短(duan)預(yu)測(ce)(ce)(ce)階(jie)段(duan)時間,會產生(sheng)散熱困難的(de)問題.而大于(yu)十小時的(de)階(jie)段(duan)設計(ji) 也(ye)往往不(bu)(bu)被(bei)采用(yong),除非(fei)可以(yi)用(yong)手動方式開始探測(ce)(ce)(ce)減少的(de)電池(chi)容量(liang).因此,由于(yu)對鎳(nie)鎘電池(chi)’記憶效應(ying)’的(de)不(bu)(bu)知和種種誤解,設計(ji)人員(yuan)應(ying) 避(bi)免在充(chong)電器上設置相關按鈕來與此’效應(ying)’進行對抗(kang).

快充階段及充電終止

快充和終(zhong)止(zhi)充電方式使用(yong)要根據(ju)蓄電池(chi)及(ji)其它(ta)設計因素(su)考(kao)慮.以下探討涉及(ji)到(dao)當今通用(yong)蓄電池(chi)快充技(ji)術的全(quan)面使用(yong).如需(xu)詳細(xi)建(jian) 議資(zi)料,可與電池(chi)制(zhi)造商應(ying)用(yong)部(bu)門聯(lian)系(xi)查詢.

鎳鎘,鎳氫蓄電池

鎳(nie)鎘和鎳(nie)氫蓄電(dian)池的(de)(de)(de)快(kuai)充(chong)(chong)(chong)(chong)程序非常(chang)(chang)類(lei)似(si),主要區別在于(yu)充(chong)(chong)(chong)(chong)電(dian)的(de)(de)(de)終止(zhi)階段.在每一(yi)個(ge)樣(yang)(yang)例中,當充(chong)(chong)(chong)(chong)電(dian)器監測(ce)電(dian)池電(dian)壓及其它(ta)數據,以(yi) 判斷何時(shi)終止(zhi)充(chong)(chong)(chong)(chong)電(dian)時(shi),都需要一(yi)個(ge)恒定(ding)電(dian)流.超過2C的(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)電(dian)流是(shi)可以(yi)做到的(de)(de)(de),但(dan)一(yi)般最常(chang)(chang)用C/2左右(you)的(de)(de)(de)電(dian)流.因(yin)充(chong)(chong)(chong)(chong)電(dian)效率無論怎樣(yang)(yang)都 要小于(yu)100%, 所以(yi)用C/2電(dian)流稍(shao)多(duo)于(yu)兩個(ge)小時(shi)的(de)(de)(de)全(quan)充(chong)(chong)(chong)(chong)是(shi)可以(yi)被接(jie)受(shou)的(de)(de)(de).

在(zai)恒流充(chong)電(dian)(dian)(dian)(dian)階段,電(dian)(dian)(dian)(dian)池(chi)端(duan)口電(dian)(dian)(dian)(dian)壓(ya)緩(huan)慢(man)上升,最(zui)終到達頂點(dian)(dian)(dian)(dian)(dian)[即坡度為零的(de)電(dian)(dian)(dian)(dian)壓(ya)最(zui)高(gao)點(dian)(dian)(dian)(dian)(dian)].鎳氫電(dian)(dian)(dian)(dian)池(chi)應(ying)在(zai)此點(dian)(dian)(dian)(dian)(dian)[0DV點(dian)(dian)(dian)(dian)(dian)]終止(zhi)充(chong)電(dian)(dian)(dian)(dian).而鎳鎘 電(dian)(dian)(dian)(dian)池(chi)則應(ying)在(zai)此點(dian)(dian)(dian)(dian)(dian)之后某點(dian)(dian)(dian)(dian)(dian)[系電(dian)(dian)(dian)(dian)池(chi)端(duan)口電(dian)(dian)(dian)(dian)壓(ya)首次出現微小降低點(dian)(dian)(dian)(dian)(dian)即-DV點(dian)(dian)(dian)(dian)(dian)]結(jie)束,請參閱圖2,可允(yun)許有少部(bu)分過(guo)充(chong).快(kuai)充(chong)如超過(guo)這兩個(ge)設 定關(guan)斷(duan)點(dian)(dian)(dian)(dian)(dian)[最(zui)高(gao)電(dian)(dian)(dian)(dian)壓(ya)點(dian)(dian)(dian)(dian)(dian)和(he)略小的(de)-DV點(dian)(dian)(dian)(dian)(dian)],都(dou)會對電(dian)(dian)(dian)(dian)池(chi)造(zao)成(cheng)損壞.這是因為快(kuai)充(chong)電(dian)(dian)(dian)(dian)流遠大于正常慢(man)充(chong)狀態所致(zhi).

圖2.對鎳鎘電池用C/2電流進行充電的參數特性

以(yi)大于C/2電(dian)(dian)(dian)流充電(dian)(dian)(dian)[充電(dian)(dian)(dian)時(shi)間(jian)不會超過兩個小時(shi)],充電(dian)(dian)(dian)器(qi)仍要監測(ce)電(dian)(dian)(dian)池溫(wen)度(du)(du)(du)和(he)電(dian)(dian)(dian)壓.因為(wei)當電(dian)(dian)(dian)池充滿時(shi),電(dian)(dian)(dian)池溫(wen)度(du)(du)(du)將上(shang)升很快(kuai),所(suo)以(yi) 溫(wen)度(du)(du)(du)監測(ce)元件(jian)要啟(qi)動另(ling)一(yi)關(guan)(guan)斷(duan)(duan)(duan)(duan)裝置.在這(zhe)(zhe)正(zheng)向上(shang)升溫(wen)度(du)(du)(du)曲線(xian)上(shang)的關(guan)(guan)斷(duan)(duan)(duan)(duan)點被稱為(wei)T關(guan)(guan)斷(duan)(duan)(duan)(duan)點.除溫(wen)度(du)(du)(du)關(guan)(guan)斷(duan)(duan)(duan)(duan)外,其(qi)它監測(ce)數據(ju)(ju),包括(kuo)已充時(shi)間(jian),最 大限(xian)定(ding)(ding)電(dian)(dian)(dian)池保護(hu)電(dian)(dian)(dian)壓,都可參預充電(dian)(dian)(dian)器(qi)關(guan)(guan)斷(duan)(duan)(duan)(duan).所(suo)以(yi)設計成(cheng)功(gong)的充電(dian)(dian)(dian)器(qi)自(zi)動關(guan)(guan)斷(duan)(duan)(duan)(duan)應依據(ju)(ju)這(zhe)(zhe)幾種監測(ce)因素[溫(wen)度(du)(du)(du)關(guan)(guan)斷(duan)(duan)(duan)(duan),充電(dian)(dian)(dian)時(shi)間(jian)關(guan)(guan)斷(duan)(duan)(duan)(duan),電(dian)(dian)(dian)池最大 限(xian)定(ding)(ding)電(dian)(dian)(dian)壓關(guan)(guan)斷(duan)(duan)(duan)(duan)等]的組合.

備注;當電池首次充(chong)(chong)(chong)電,會(hui)產生模仿關斷狀態(tai)的特定效應,因此在激活關斷模式監測(ce)曲(qu)線(xian)前,充(chong)(chong)(chong)電器會(hui)引入一個 一到(dao)五分(fen)鐘的緩沖期.另外,充(chong)(chong)(chong)電關斷狀態(tai)在低于(yu)C\8電流(liu)充(chong)(chong)(chong)電時很(hen)難監測(ce)到(dao)數據,這(zhe)是(shi)因為與其他系(xi)統(tong)(tong)數據比較, 電壓和(he)(he)溫度(du)曲(qu)線(xian)[V/t和(he)(he)T/t]斜率很(hen)小(xiao)所(suo)致.為快速充(chong)(chong)(chong)電的安全起見,這(zhe)些系(xi)統(tong)(tong)中的硬軟件配置(zhi)總(zong)是(shi)會(hui)造成充(chong)(chong)(chong)電器提 前關斷的誤操(cao)作(zuo)動(dong)作(zuo).

 

鋰離子電池

鋰離子蓄電(dian)(dian)池充(chong)(chong)電(dian)(dian)曲(qu)線(xian)和鎳離子蓄電(dian)(dian)池相比很(hen)不一樣.充(chong)(chong)電(dian)(dian)關(guan)斷要確(que)定(ding)到最大安全(quan)值(zhi)之后才(cai)會動(dong)作.鋰電(dian)(dian)充(chong)(chong)電(dian)(dian)器要將充(chong)(chong)電(dian)(dian)電(dian)(dian)壓(ya)控制(zhi) 在小于(yu)0.75%的精確(que)范圍內,并且其(qi)最大充(chong)(chong)電(dian)(dian)效率用充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)限(xian)定(ding)控制(zhi),非(fei)常類似臺式桌面型直流(liu)電(dian)(dian)源(yuan). 當快充(chong)(chong)開(kai)始(shi)時,電(dian)(dian)池端(duan)口(kou)電(dian)(dian)壓(ya)相 對較低(di),充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)就(jiu)等同于(yu)其(qi)限(xian)定(ding)電(dian)(dian)流(liu)值(zhi).

在充(chong)(chong)電(dian)(dian)(dian)過程中,電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)緩(huan)慢上(shang)(shang)升.最后,充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流到(dao)達設定峰(feng)值,充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)上(shang)(shang)升到(dao)每節 4.2V的浮充(chong)(chong)電(dian)(dian)(dian)壓(ya)水平[見圖4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)到(dao)浮充(chong)(chong)電(dian)(dian)(dian)(dian)壓水平,充(chong)(chong)電(dian)(dian)(dian)(dian)器就可(ke)以終止充(chong)(chong)電(dian)(dian)(dian)(dian)了,但這(zhe)種方式忽(hu)略了充(chong)(chong)電(dian)(dian)(dian)(dian)峰頂(ding)值(zhi)關(guan)斷操作(zuo).如在浮充(chong)(chong)電(dian)(dian)(dian)(dian)壓階段(duan),充(chong)(chong)電(dian)(dian)(dian)(dian)器會開始 定時器的操作(zuo),在一段(duan)設定緩沖(chong)期后,自動終止充(chong)(chong)電(dian)(dian)(dian)(dian).另一方式,也(ye)可(ke)監(jian)測充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu),在一個較低電(dian)(dian)(dian)(dian)流(liu)水平關(guan)斷[典型地用(yong)0.05的限定值(zhi), 一些(xie)制(zhi)造(zao)商建議(yi)使用(yong)相對較高的100mA電(dian)(dian)(dian)(dian)流(liu)最小值(zhi)].充(chong)(chong)電(dian)(dian)(dian)(dian)峰值(zhi)關(guan)斷環路往(wang)往(wang)也(ye)依靠這(zhe)種技術.

最近幾年,在鋰離(li)(li)子電池(chi)(chi)和其充電器,以及(ji)對(dui)這(zhe)種新型電池(chi)(chi)的(de)(de)(de)(de)(de)了(le)解方面(mian),都取得了(le)相當的(de)(de)(de)(de)(de)進展(zhan).最早期的(de)(de)(de)(de)(de)鋰離(li)(li)子電池(chi)(chi)在用戶的(de)(de)(de)(de)(de)使用方 面(mian)都有一(yi)些(xie)安全層(ceng)面(mian)的(de)(de)(de)(de)(de)缺點,而(er)這(zhe)些(xie)問題(ti)已(yi)不會(hui)(hui)出(chu)現在當今(jin)設計成功的(de)(de)(de)(de)(de)系統上了(le).制造商們的(de)(de)(de)(de)(de)建議既不會(hui)(hui)一(yi)成不變(bian),也不會(hui)(hui)完(wan)全一(yi)致, 而(er)鋰離(li)(li)子電池(chi)(chi)技(ji)術會(hui)(hui)繼續向前(qian)發(fa)展(zhan).

鋰聚合(he)物(wu)電池(chi)的充電要求和鋰離子電池(chi)的要求是一(yi)樣的，可以按同類對待。

最新出(chu)現的(de)磷(lin)酸鐵鋰(li)電(dian)池的(de)電(dian)壓(ya)(ya)(ya)比鋰(li)離(li)子電(dian)池的(de)額度電(dian)壓(ya)(ya)(ya)要低0.4V左右，充(chong)電(dian)的(de)恒壓(ya)(ya)(ya)電(dian)壓(ya)(ya)(ya)設定(ding)值為(wei)3.7V/節為(wei)宜。充(chong)電(dian)的(de)方(fang)式與(yu) 鋰(li)離(li)子電(dian)池基本相同（注意只是電(dian)壓(ya)(ya)(ya)要低一些！）

 

鉛酸電池.

鉛酸[PbSO4]蓄電(dian)池既可以用限流充(chong)電(dian),也可以用較通(tong)用簡單的限壓充(chong)電(dian).限壓充(chong)電(dian)與前者具(ju)有類似的作用功能,而(er)高(gao)精確(que)性(xing)并非是(shi) 其關鍵.這需要設置(zhi)一個高(gao)于電(dian)池浮充(chong)電(dian)壓的限流電(dian)壓源[大(da)約2.45V左(zuo)右(you)].

經過預設(she)狀(zhuang)態操作(zuo),充(chong)(chong)電(dian)器確認開始快(kuai)充(chong)(chong),一直延續到最小充(chong)(chong)電(dian)電(dian)流[這個過程類似鋰離子電(dian)池充(chong)(chong)電(dian)器],然后快(kuai)充(chong)(chong)終止.這時充(chong)(chong)電(dian)器 需要一段Vf浮充(chong)(chong)電(dian)壓(ya)(ya)進(jin)行(xing)維(wei)(wei)護(hu)[通(tong)常用2.25V左(zuo)右(you)電(dian)壓(ya)(ya)].鉛酸(suan)[PbSO4]蓄電(dian)池允許在非確定(ding)階段用此浮充(chong)(chong)電(dian)壓(ya)(ya)進(jin)行(xing)維(wei)(wei)護(hu)[見(jian)圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高溫環境(jing)下,對(dui)鉛酸[PbSO4]蓄(xu)電池(chi)進(jin)行快(kuai)充(chong)(chong)的(de)電流要根據每攝氏度(du)0.3百分(fen)比的(de)標準溫度(du)系數(shu)進(jin)行調低.快(kuai)充(chong)(chong)時設定(ding)最大電池(chi)溫度(du) 建議在50’C左右,但(dan)浮充(chong)(chong)一般可(ke)以超過這個溫度(du).

 

可選擇的涓流充電[適合除鋰離子電池外的其它蓄電池]

除(chu)鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)池(chi)(chi)外,其它蓄(xu)電(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器經常(chang)設置(zhi)(zhi)有一(yi)個可供選(xuan)擇的涓流充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)階段.這個階段的設置(zhi)(zhi)可以用來補償電(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)滿(man)后本體的自(zi)放(fang)電(dian)(dian)(dian) 現象(xiang).鉛(qian)酸[PbSO4]電(dian)(dian)(dian)池(chi)(chi)自(zi)放(fang)電(dian)(dian)(dian)率(lv)最大[每天呈數個百(bai)分點],而鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)池(chi)(chi)最低.鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)池(chi)(chi)的自(zi)放(fang)電(dian)(dian)(dian)率(lv)有時低到已無需涓充(chong)(chong)(chong)(chong)來維護(hu).然(ran)而, 鎳鎘[NiCds]蓄(xu)電(dian)(dian)(dian)池(chi)(chi)卻(que)經常(chang),不(bu)定地需要C/16的涓充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)流以進(jin)行維護(hu).對鎳氫[NiMH]蓄(xu)電(dian)(dian)(dian)池(chi)(chi)而言(yan),安全的持(chi)續(xu)放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流經常(chang)在C/50左右,而涓 流充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)一(yi)般不(bu)被建議.

續放(fang)電(dian)電(dian)流經常在C/50左(zuo)右,而涓 流充電(dian)一般不被建議(yi).