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(fang)法在充電(dian)(dian)初期電(dian)(dian)池內阻極低致使充電(dian)(dian)電(dian)(dian)流(liu)過大，而隨時間并不(bu)按指(zhi)數規律(lv)下降常偏離制定(ding)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刻(ke)總(zong) 存在一個(ge)最佳的充電電流(liu)和(he)充電模式的，問題是我們如何才能(neng)逼近(jin)這個(ge)最佳值。 

綜合起來，判斷(duan)規則(ze)有如下幾種：

●定時控制；

●電(dian)壓(ya)控制(含(han)最高電(dian)壓(ya)：電(dian)壓(ya)負增量：電(dian)壓(ya)零增量等)；

●溫度控制(包括最高(gao)溫度，最高(gao)溫升(sheng)：溫度變化(hua)率等)；

●電流控制等。

較好的辦法(fa)是采用(yong)綜合判斷方法(fa)，對每個(ge)指標進行跟蹤，并(bing)按模糊數學原理分(fen)別記分(fen)，按照置(zhi)信(xin)度做出(chu)最佳判斷。 電池快(kuai)速充(chong)電分(fen)為幾個(ge)階(jie)段,見本(ben)文(wen)所述及通用(yong)充(chong)電器運(yun)行簡圖.[圖1]

　

 

圖1.通用電池充電器(qi)充電參數(shu)圖表.

 

起始階段

起(qi)始(shi)階段(duan)(duan)在(zai)充(chong)(chong)電(dian)(dian)(dian)過(guo)(guo)程中雖(sui)不(bu)(bu)屬于(yu)真正(zheng)起(qi)作用的(de)那(nei)幾(ji)個階段(duan)(duan),但在(zai)整(zheng)個充(chong)(chong)電(dian)(dian)(dian)過(guo)(guo)程中,起(qi)始(shi)階段(duan)(duan)仍是一個非常(chang)重(zhong)(zhong)要(yao)的(de)滿足條件(jian). 充(chong)(chong)電(dian)(dian)(dian)器啟(qi)動(dong)以(yi)(yi)后(hou)開始(shi)自測(ce),如(ru)(ru)電(dian)(dian)(dian)源(yuan)出現故障或(huo)(huo)反復起(qi)動(dong),充(chong)(chong)電(dian)(dian)(dian)過(guo)(guo)程就會被(bei)打斷(duan).如(ru)(ru)果(guo)缺(que)乏(fa)相應(ying)智能(neng)(neng)或(huo)(huo)時(shi)(shi)間關斷(duan)裝置(zhi)以(yi)(yi)及電(dian)(dian)(dian)池(chi)(chi)密 封(feng)性能(neng)(neng)不(bu)(bu)能(neng)(neng)得到改善,那(nei)么此(ci)種(zhong)現象往往會被(bei)忽視.幾(ji)乎所有的(de)充(chong)(chong)電(dian)(dian)(dian)器在(zai)電(dian)(dian)(dian)源(yuan)出現故障以(yi)(yi)后(hou)都(dou)可以(yi)(yi)完全重(zhong)(zhong)新啟(qi)動(dong),但如(ru)(ru)過(guo)(guo)充(chong)(chong)不(bu)(bu) 被(bei)允(yun)許,充(chong)(chong)電(dian)(dian)(dian)器要(yao)能(neng)(neng)夠進行特別的(de)自測(ce)程序以(yi)(yi)判斷(duan)電(dian)(dian)(dian)池(chi)(chi)是否早已充(chong)(chong)滿.電(dian)(dian)(dian)池(chi)(chi)狀態要(yao)顯現在(zai)充(chong)(chong)電(dian)(dian)(dian)器指示燈或(huo)(huo)類似的(de)顯示裝置(zhi)上(shang). （不(bu)(bu)好的(de)案例：例如(ru)(ru)只靠定(ding)時(shi)(shi)的(de)充(chong)(chong)電(dian)(dian)(dian)器,用四個小時(shi)(shi)間隔的(de)固定(ding)時(shi)(shi)間給電(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian).如(ru)(ru)果(guo)充(chong)(chong)電(dian)(dian)(dian)三小時(shi)(shi)59分鐘,電(dian)(dian)(dian)源(yuan)出現故障斷(duan)電(dian)(dian)(dian), 當(dang)故障清除重(zhong)(zhong)新送電(dian)(dian)(dian)以(yi)(yi)后(hou),充(chong)(chong)電(dian)(dian)(dian)器又(you)會開始(shi)重(zhong)(zhong)新一輪的(de)四小時(shi)(shi)固定(ding)充(chong)(chong)電(dian)(dian)(dian),從而造成(cheng)電(dian)(dian)(dian)池(chi)(chi)過(guo)(guo)充(chong)(chong)四個小時(shi)(shi).這種(zhong)結果(guo)往往會對電(dian)(dian)(dian)池(chi)(chi) 造成(cheng)損壞。因此(ci)原(yuan)因,定(ding)時(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)器很少被(bei)采用。）

充電時可充電池應備條件

當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)連接上(shang)(shang)充(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)以后,此(ci)充(chong)電(dian)(dian)(dian)(dian)階段(duan)之(zhi)充(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)要能夠有所感應顯(xian)示以及彼(bi)電(dian)(dian)(dian)(dian)池(chi)(chi)是否可以進(jin)行充(chong)電(dian)(dian)(dian)(dian).一(yi)般當(dang)充(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)電(dian)(dian)(dian)(dian)源關(guan)斷(duan) 的(de)情況下,此(ci)電(dian)(dian)(dian)(dian)池(chi)(chi)感應裝置(zhi)通常根據充(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)接頭的(de)端口電(dian)(dian)(dian)(dian)壓(ya)來進(jin)行判斷(duan),但當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)已經(jing)(jing)反復過度使用或端口電(dian)(dian)(dian)(dian)壓(ya)極低(di)的(de)情況下, 這種感應裝置(zhi)往往會(hui)產生(sheng)問題(ti).作為(wei)一(yi)種替代(dai)方法,充(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)經(jing)(jing)常根據溫(wen)度或電(dian)(dian)(dian)(dian)壓(ya)瞬時跳變來達(da)到上(shang)(shang)述(shu)目的(de).這種硬件設置(zhi)同樣適 用于電(dian)(dian)(dian)(dian)池(chi)(chi)組.

一(yi)(yi)旦充(chong)(chong)電(dian)(dian)(dian)器感應連接到(dao)了(le)可充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池(chi)(chi),它還必須(xu)判斷出(chu)(chu)電(dian)(dian)(dian)池(chi)(chi)是(shi)否具(ju)備良好(hao)可充(chong)(chong)條件.在(zai)這(zhe)個(ge)次級(ji)階段(duan)(duan)[限定(ding)條件],電(dian)(dian)(dian)池(chi)(chi)要能(neng)夠 被檢測出(chu)(chu)其基本功能(neng)狀態;開路,短路,高溫(wen)或是(shi)低(di)溫(wen).以此(ci)來(lai)檢測電(dian)(dian)(dian)池(chi)(chi)是(shi)否具(ju)備可充(chong)(chong)性,一(yi)(yi)些鉛酸(suan)充(chong)(chong)電(dian)(dian)(dian)器類型特別需(xu)要一(yi)(yi)個(ge)可通過(guo) LED燈來(lai)顯(xian)示出(chu)(chu)其充(chong)(chong)電(dian)(dian)(dian)的主充(chong)(chong)電(dian)(dian)(dian)流(liu)[大約以五分之一(yi)(yi)的快充(chong)(chong)額定(ding)電(dian)(dian)(dian)流(liu)],并允許電(dian)(dian)(dian)池(chi)(chi)在(zai)一(yi)(yi)固定(ding)充(chong)(chong)電(dian)(dian)(dian)時間段(duan)(duan)內(nei)達(da)到(dao)其特定(ding)的電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓. 這(zhe)種技術對(dui)已經反復過(guo)度使用的鉛酸(suan)[PbSO4]蓄電(dian)(dian)(dian)池(chi)(chi),應避免出(chu)(chu)現反接的問題.

對外圍設備和(he)電(dian)池溫(wen)度(du)的(de)檢測(ce)(ce)也是本階段(duan)必要(yao)條件之一(yi)(yi).當(dang)充電(dian)器(qi)檢測(ce)(ce)到(dao)電(dian)池的(de)溫(wen)度(du)過高或過低,一(yi)(yi)般會等待一(yi)(yi)段(duan)預先(xian)設定(ding)的(de) 時(shi)間(jian)以使其(qi)恢復正(zheng)常.如在設定(ding)時(shi)間(jian)內(nei)并未恢復正(zheng)常,充電(dian)器(qi)會自動(dong)改變充電(dian)電(dian)流(liu),這個動(dong)作相應就(jiu)(jiu)調整了電(dian)池溫(wen)度(du),所以充電(dian)效率(lv) 會大大增加.最后,充電(dian)器(qi)需要(yao)檢測(ce)(ce)一(yi)(yi)下與電(dian)池的(de)連(lian)接狀態(tai)是開路抑或短路.通常開路狀態(tai)容(rong)易檢測(ce)(ce),而一(yi)(yi)旦出現短路顯示,就(jiu)(jiu)需要(yao)進 一(yi)(yi)步(bu)確(que)認(ren),以避免造成事故的(de)發生.如果(guo)所有檢測(ce)(ce)都(dou)獲得通過,就(jiu)(jiu)可以給電(dian)池充電(dian)了.這種設置相當(dang)領先(xian),請參(can)閱附圖(tu)1

預先充電條件設置[自選類型]

有一些充(chong)電(dian)(dian)器[如早(zao)期(qi)(qi)出現(xian)的(de)(de)鎳鎘(ge)電(dian)(dian)池(chi)]都設(she)計有一個(ge)充(chong)電(dian)(dian)前期(qi)(qi)預測階(jie)段,用以(yi)判(pan)斷(duan)在重新充(chong)電(dian)(dian)前，待(dai)測電(dian)(dian)池(chi)是否已‘完(wan)(wan)全(quan)’放(fang)電(dian)(dian). 所(suo)謂‘完(wan)(wan)全(quan)’放(fang)電(dian)(dian)系指每節電(dian)(dian)池(chi)的(de)(de)端口電(dian)(dian)壓放(fang)電(dian)(dian)到1V的(de)(de)水平,以(yi)去除電(dian)(dian)解液中的(de)(de)枝狀結構(gou),這也是人們為什么經常錯誤地理解‘記憶 效(xiao)應’的(de)(de)原(yuan)因(yin)[通常電(dian)(dian)池(chi)一次(ci)可(ke)充(chong)電(dian)(dian)容(rong)量是上次(ci)放(fang)電(dian)(dian)容(rong)量的(de)(de)104—110百(bai)分比].這種所(suo)謂的(de)(de)‘記憶效(xiao)應’特指電(dian)(dian)池(chi)內(nei)部(bu)電(dian)(dian)解液枝狀結 構(gou)狀態的(de)(de)自我恢復能力(li),如受到破壞,將(jiang)減(jian)少電(dian)(dian)池(chi)的(de)(de)使用壽命.所(suo)以(yi)按正(zheng)常時間周期(qi)(qi)進行的(de)(de)充(chong)放(fang)電(dian)(dian),往往會解決這個(ge)問題.

在每次充電(dian)前,此(ci)(ci)預測(ce)(ce)階(jie)段(duan)都會被自動完成(cheng),或在電(dian)池(chi)(chi)充電(dian)剩余過(guo)半顯(xian)示[通過(guo)連接(jie)測(ce)(ce)試或其(qi)它操作(zuo)]之(zhi)后.預測(ce)(ce)階(jie)段(duan)一般(ban)從一到十(shi)小 時(shi)(shi)不等.在一小時(shi)(shi)之(zhi)內放空電(dian)池(chi)(chi)通常(chang)不予考慮.而通過(guo)連接(jie)電(dian)阻縮短預測(ce)(ce)階(jie)段(duan)時(shi)(shi)間,會產生(sheng)散熱困(kun)難(nan)的(de)問題.而大(da)于(yu)十(shi)小時(shi)(shi)的(de)階(jie)段(duan)設(she)計(ji) 也往往不被采用,除非可以(yi)用手動方式開(kai)始(shi)探測(ce)(ce)減(jian)少的(de)電(dian)池(chi)(chi)容量.因此(ci)(ci),由于(yu)對鎳(nie)鎘電(dian)池(chi)(chi)’記憶效應(ying)’的(de)不知和種種誤解,設(she)計(ji)人員(yuan)應(ying) 避免在充電(dian)器上設(she)置相關(guan)按(an)鈕來與(yu)此(ci)(ci)’效應(ying)’進行對抗.

快充階段及充電終止

快充(chong)(chong)和(he)終(zhong)止(zhi)充(chong)(chong)電(dian)(dian)方式使(shi)用(yong)要根據蓄電(dian)(dian)池及其它設計(ji)因(yin)素考慮.以下探討涉及到當今通(tong)用(yong)蓄電(dian)(dian)池快充(chong)(chong)技術的(de)全面(mian)使(shi)用(yong).如需詳細建(jian) 議資料(liao),可與(yu)電(dian)(dian)池制造(zao)商應(ying)用(yong)部門聯系查詢.

鎳鎘,鎳氫蓄電池

鎳鎘和鎳氫蓄電(dian)(dian)(dian)池的快充(chong)(chong)程序非(fei)常類似,主要(yao)區別在于充(chong)(chong)電(dian)(dian)(dian)的終(zhong)止階段.在每一個(ge)樣例中,當(dang)充(chong)(chong)電(dian)(dian)(dian)器監測電(dian)(dian)(dian)池電(dian)(dian)(dian)壓及(ji)其它數(shu)據,以(yi) 判(pan)斷何時終(zhong)止充(chong)(chong)電(dian)(dian)(dian)時,都需要(yao)一個(ge)恒定電(dian)(dian)(dian)流(liu)(liu).超過2C的充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)是可以(yi)做(zuo)到的,但一般最常用C/2左(zuo)右的電(dian)(dian)(dian)流(liu)(liu).因充(chong)(chong)電(dian)(dian)(dian)效率無(wu)論怎樣都 要(yao)小于100%, 所以(yi)用C/2電(dian)(dian)(dian)流(liu)(liu)稍(shao)多(duo)于兩個(ge)小時的全充(chong)(chong)是可以(yi)被接受的.

在(zai)恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階段,電(dian)(dian)(dian)(dian)池(chi)(chi)端(duan)口電(dian)(dian)(dian)(dian)壓緩慢上升,最終到達頂點(dian)(dian)(dian)(dian)(dian)(dian)[即坡度(du)為零的電(dian)(dian)(dian)(dian)壓最高點(dian)(dian)(dian)(dian)(dian)(dian)].鎳(nie)氫電(dian)(dian)(dian)(dian)池(chi)(chi)應(ying)在(zai)此(ci)點(dian)(dian)(dian)(dian)(dian)(dian)[0DV點(dian)(dian)(dian)(dian)(dian)(dian)]終止充(chong)(chong)(chong)電(dian)(dian)(dian)(dian).而(er)鎳(nie)鎘 電(dian)(dian)(dian)(dian)池(chi)(chi)則應(ying)在(zai)此(ci)點(dian)(dian)(dian)(dian)(dian)(dian)之后某點(dian)(dian)(dian)(dian)(dian)(dian)[系電(dian)(dian)(dian)(dian)池(chi)(chi)端(duan)口電(dian)(dian)(dian)(dian)壓首次出現微小降低點(dian)(dian)(dian)(dian)(dian)(dian)即-DV點(dian)(dian)(dian)(dian)(dian)(dian)]結束,請參閱圖2,可允許有少部分過(guo)充(chong)(chong)(chong).快充(chong)(chong)(chong)如超過(guo)這兩個設 定關斷點(dian)(dian)(dian)(dian)(dian)(dian)[最高電(dian)(dian)(dian)(dian)壓點(dian)(dian)(dian)(dian)(dian)(dian)和略(lve)小的-DV點(dian)(dian)(dian)(dian)(dian)(dian)],都會對電(dian)(dian)(dian)(dian)池(chi)(chi)造成損壞.這是因為快充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)流(liu)遠大于(yu)正常(chang)慢充(chong)(chong)(chong)狀(zhuang)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

以大(da)于C/2電(dian)(dian)(dian)(dian)(dian)流充(chong)電(dian)(dian)(dian)(dian)(dian)[充(chong)電(dian)(dian)(dian)(dian)(dian)時間不(bu)會超過兩(liang)個小(xiao)時],充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)仍要(yao)監測(ce)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)溫度和電(dian)(dian)(dian)(dian)(dian)壓.因(yin)為當電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)滿(man)時,電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)溫度將上升(sheng)很快,所(suo)以 溫度監測(ce)元件(jian)要(yao)啟動(dong)另一關(guan)斷(duan)(duan)(duan)(duan)裝置(zhi).在這正(zheng)向上升(sheng)溫度曲線(xian)上的關(guan)斷(duan)(duan)(duan)(duan)點(dian)被稱為T關(guan)斷(duan)(duan)(duan)(duan)點(dian).除溫度關(guan)斷(duan)(duan)(duan)(duan)外,其它監測(ce)數據,包括已充(chong)時間,最 大(da)限(xian)定(ding)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)保護(hu)電(dian)(dian)(dian)(dian)(dian)壓,都可(ke)參(can)預充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)關(guan)斷(duan)(duan)(duan)(duan).所(suo)以設計成功的充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)自動(dong)關(guan)斷(duan)(duan)(duan)(duan)應依據這幾種(zhong)監測(ce)因(yin)素[溫度關(guan)斷(duan)(duan)(duan)(duan),充(chong)電(dian)(dian)(dian)(dian)(dian)時間關(guan)斷(duan)(duan)(duan)(duan),電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)最大(da) 限(xian)定(ding)電(dian)(dian)(dian)(dian)(dian)壓關(guan)斷(duan)(duan)(duan)(duan)等]的組合(he).

備注;當電池首次充(chong)(chong)(chong)電,會產生模(mo)仿關(guan)斷狀態(tai)(tai)的特定效(xiao)應(ying),因(yin)此在激活(huo)關(guan)斷模(mo)式監(jian)測曲線前,充(chong)(chong)(chong)電器會引(yin)入(ru)一(yi)個 一(yi)到五(wu)分鐘的緩沖期(qi).另外(wai),充(chong)(chong)(chong)電關(guan)斷狀態(tai)(tai)在低于(yu)C\8電流充(chong)(chong)(chong)電時很難監(jian)測到數據(ju),這(zhe)是因(yin)為(wei)與其他(ta)系統(tong)(tong)數據(ju)比較, 電壓和溫度曲線[V/t和T/t]斜率很小所致.為(wei)快速充(chong)(chong)(chong)電的安(an)全起見,這(zhe)些系統(tong)(tong)中(zhong)的硬(ying)軟件(jian)配(pei)置總是會造成充(chong)(chong)(chong)電器提(ti) 前關(guan)斷的誤操作動作.

 

鋰離子電池

鋰(li)離子蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)曲線和鎳離子蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池相比很不(bu)一樣.充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)關斷要確定到最大安全值之后才會動作(zuo).鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)要將充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓控制 在小(xiao)于0.75%的精確范圍內,并且其(qi)最大充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)效率用充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)限(xian)定控制,非常(chang)類似臺式桌面型直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源. 當快充(chong)開(kai)始時,電(dian)(dian)(dian)(dian)(dian)(dian)池端口電(dian)(dian)(dian)(dian)(dian)(dian)壓相 對(dui)較低,充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)就等同于其(qi)限(xian)定電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)值.

在充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過程(cheng)中,電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓緩慢上升(sheng)(sheng).最后(hou),充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)到達(da)設定峰值,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓上升(sheng)(sheng)到每節 4.2V的(de)浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓水(shui)平(ping)[見圖4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)到(dao)浮(fu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)壓水平,充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器就可以(yi)終止(zhi)(zhi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)了(le),但(dan)這種方式忽略了(le)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)峰頂值關(guan)斷操(cao)作(zuo).如(ru)在(zai)浮(fu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)壓階段,充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器會開始 定時器的操(cao)作(zuo),在(zai)一段設定緩(huan)沖期后(hou),自(zi)動(dong)終止(zhi)(zhi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian).另一方式,也可監測充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流,在(zai)一個(ge)較(jiao)低(di)電(dian)(dian)(dian)流水平關(guan)斷[典型地用0.05的限定值, 一些制造商(shang)建議使用相對較(jiao)高的100mA電(dian)(dian)(dian)流最(zui)小(xiao)值].充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)峰值關(guan)斷環路往往也依靠(kao)這種技(ji)術.

最近(jin)幾年,在(zai)(zai)鋰(li)(li)(li)離子電池(chi)和(he)其(qi)充電器(qi),以及對(dui)這(zhe)種新型電池(chi)的(de)(de)(de)了(le)解方面(mian),都取得了(le)相當的(de)(de)(de)進展(zhan).最早期的(de)(de)(de)鋰(li)(li)(li)離子電池(chi)在(zai)(zai)用戶(hu)的(de)(de)(de)使(shi)用方 面(mian)都有一些安全層面(mian)的(de)(de)(de)缺點,而這(zhe)些問(wen)題(ti)已不(bu)會(hui)(hui)出現(xian)在(zai)(zai)當今設計成功的(de)(de)(de)系統(tong)上了(le).制(zhi)造商們的(de)(de)(de)建議(yi)既不(bu)會(hui)(hui)一成不(bu)變,也不(bu)會(hui)(hui)完全一致, 而鋰(li)(li)(li)離子電池(chi)技(ji)術會(hui)(hui)繼續向前發展(zhan).

鋰聚合(he)物(wu)電池(chi)的(de)(de)充電要求和鋰離(li)子(zi)電池(chi)的(de)(de)要求是一(yi)樣的(de)(de)，可以按同類對待。

最(zui)新出現的(de)磷酸鐵(tie)鋰電(dian)池(chi)的(de)電(dian)壓比鋰離子電(dian)池(chi)的(de)額度電(dian)壓要(yao)低0.4V左右，充(chong)電(dian)的(de)恒壓電(dian)壓設定值為(wei)3.7V/節為(wei)宜。充(chong)電(dian)的(de)方(fang)式與 鋰離子電(dian)池(chi)基(ji)本相同（注意只是(shi)電(dian)壓要(yao)低一些(xie)！）

 

鉛酸電池.

鉛(qian)酸[PbSO4]蓄電(dian)池(chi)既可(ke)以(yi)用(yong)限流充電(dian),也可(ke)以(yi)用(yong)較通用(yong)簡單(dan)的限壓充電(dian).限壓充電(dian)與前者具有類似的作(zuo)用(yong)功能,而高(gao)精確性并非是 其關鍵.這需(xu)要設置一個高(gao)于電(dian)池(chi)浮(fu)充電(dian)壓的限流電(dian)壓源[大約(yue)2.45V左右].

經過預設狀態操(cao)作(zuo),充(chong)(chong)電(dian)(dian)(dian)(dian)器確(que)認開始快充(chong)(chong),一直延續(xu)到最小充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流[這個(ge)過程類似鋰離子電(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)器],然后快充(chong)(chong)終止.這時充(chong)(chong)電(dian)(dian)(dian)(dian)器 需要一段Vf浮(fu)(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)壓進行維(wei)護[通常用2.25V左右電(dian)(dian)(dian)(dian)壓].鉛酸[PbSO4]蓄(xu)電(dian)(dian)(dian)(dian)池允許在非(fei)確(que)定階段用此浮(fu)(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)壓進行維(wei)護[見圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高(gao)溫環境下,對鉛酸[PbSO4]蓄電池進行快充(chong)的(de)電流(liu)要根據每攝氏度0.3百分(fen)比的(de)標準溫度系數進行調低.快充(chong)時(shi)設定(ding)最大(da)電池溫度 建議在50’C左右,但(dan)浮充(chong)一(yi)般可以超(chao)過這(zhe)個(ge)溫度.

 

可選擇的涓流充電[適合除鋰離子電池外的其它蓄電池]

除鋰(li)離(li)(li)子(zi)電(dian)(dian)(dian)池(chi)(chi)外,其它蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)器經(jing)常(chang)設(she)置有一個可供選擇的(de)(de)涓(juan)流(liu)(liu)充(chong)電(dian)(dian)(dian)階段.這個階段的(de)(de)設(she)置可以用來補償(chang)電(dian)(dian)(dian)池(chi)(chi)充(chong)滿后本(ben)體的(de)(de)自放(fang)電(dian)(dian)(dian) 現象.鉛酸[PbSO4]電(dian)(dian)(dian)池(chi)(chi)自放(fang)電(dian)(dian)(dian)率最(zui)大[每天呈數個百分點],而(er)鋰(li)離(li)(li)子(zi)電(dian)(dian)(dian)池(chi)(chi)最(zui)低(di).鋰(li)離(li)(li)子(zi)電(dian)(dian)(dian)池(chi)(chi)的(de)(de)自放(fang)電(dian)(dian)(dian)率有時(shi)低(di)到(dao)已(yi)無需涓(juan)充(chong)來維護.然而(er), 鎳(nie)鎘[NiCds]蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)卻經(jing)常(chang),不定地(di)需要C/16的(de)(de)涓(juan)充(chong)電(dian)(dian)(dian)流(liu)(liu)以進行維護.對鎳(nie)氫(qing)[NiMH]蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)而(er)言,安全的(de)(de)持續放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)經(jing)常(chang)在C/50左右,而(er)涓(juan) 流(liu)(liu)充(chong)電(dian)(dian)(dian)一般不被建議.

續放電(dian)(dian)電(dian)(dian)流(liu)經常在C/50左(zuo)右,而涓 流(liu)充電(dian)(dian)一般不被(bei)建議(yi).