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(ming)，而恒壓 充電(dian)(dian)(dian)方法在充電(dian)(dian)(dian)初(chu)期電(dian)(dian)(dian)池內阻極低致使充電(dian)(dian)(dian)電(dian)(dian)(dian)流過大，而隨時間并不按指數規律下降常偏離(li)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(de)任(ren)意(yi)時刻總 存在一個最佳(jia)的(de)充電電流和充電模式的(de)，問題是我們如(ru)何才能逼近這個最佳(jia)值。 

綜合(he)起(qi)來，判(pan)斷規則(ze)有如下幾種：

●定時控制；

●電(dian)壓(ya)控制(含最(zui)高(gao)電(dian)壓(ya)：電(dian)壓(ya)負增量：電(dian)壓(ya)零增量等)；

●溫度控制(包括最高溫度，最高溫升：溫度變化(hua)率(lv)等)；

●電流控制等。

較好的辦法是(shi)采用綜(zong)合(he)判斷方(fang)法，對(dui)每個指(zhi)標進行跟蹤，并按模糊數學原理(li)分別記分，按照置信度做出(chu)最佳(jia)判斷。 電(dian)池快速充(chong)電(dian)分為幾個階段,見本文所述及通(tong)用充(chong)電(dian)器運行簡圖.[圖1]

　

 

圖1.通用電(dian)池充(chong)電(dian)器充(chong)電(dian)參數圖表.

 

起始階段

起始階(jie)段在(zai)(zai)充電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)中(zhong)雖(sui)不(bu)屬于真(zhen)正起作用(yong)的(de)那(nei)幾(ji)個(ge)(ge)階(jie)段,但(dan)在(zai)(zai)整(zheng)個(ge)(ge)充電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)中(zhong),起始階(jie)段仍是一(yi)個(ge)(ge)非(fei)常重(zhong)要(yao)的(de)滿足條件(jian). 充電(dian)(dian)(dian)(dian)器(qi)(qi)啟動以后(hou)開(kai)(kai)始自測,如(ru)電(dian)(dian)(dian)(dian)源(yuan)出(chu)現(xian)故障(zhang)或反復(fu)起動,充電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)就會被打斷(duan).如(ru)果(guo)缺乏相(xiang)應(ying)智能(neng)(neng)或時(shi)(shi)(shi)間(jian)關斷(duan)裝(zhuang)置以及電(dian)(dian)(dian)(dian)池密 封性能(neng)(neng)不(bu)能(neng)(neng)得到改善,那(nei)么此(ci)(ci)種(zhong)現(xian)象往(wang)往(wang)會被忽視.幾(ji)乎所有的(de)充電(dian)(dian)(dian)(dian)器(qi)(qi)在(zai)(zai)電(dian)(dian)(dian)(dian)源(yuan)出(chu)現(xian)故障(zhang)以后(hou)都可以完全重(zhong)新啟動,但(dan)如(ru)過(guo)(guo)充不(bu) 被允(yun)許,充電(dian)(dian)(dian)(dian)器(qi)(qi)要(yao)能(neng)(neng)夠(gou)進行特(te)別的(de)自測程(cheng)序以判斷(duan)電(dian)(dian)(dian)(dian)池是否早已充滿.電(dian)(dian)(dian)(dian)池狀態要(yao)顯現(xian)在(zai)(zai)充電(dian)(dian)(dian)(dian)器(qi)(qi)指示(shi)燈或類(lei)似的(de)顯示(shi)裝(zhuang)置上. （不(bu)好的(de)案例：例如(ru)只靠定(ding)時(shi)(shi)(shi)的(de)充電(dian)(dian)(dian)(dian)器(qi)(qi),用(yong)四個(ge)(ge)小(xiao)時(shi)(shi)(shi)間(jian)隔(ge)的(de)固定(ding)時(shi)(shi)(shi)間(jian)給電(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian).如(ru)果(guo)充電(dian)(dian)(dian)(dian)三小(xiao)時(shi)(shi)(shi)59分(fen)鐘(zhong),電(dian)(dian)(dian)(dian)源(yuan)出(chu)現(xian)故障(zhang)斷(duan)電(dian)(dian)(dian)(dian), 當(dang)故障(zhang)清(qing)除重(zhong)新送電(dian)(dian)(dian)(dian)以后(hou),充電(dian)(dian)(dian)(dian)器(qi)(qi)又會開(kai)(kai)始重(zhong)新一(yi)輪的(de)四小(xiao)時(shi)(shi)(shi)固定(ding)充電(dian)(dian)(dian)(dian),從而造(zao)成電(dian)(dian)(dian)(dian)池過(guo)(guo)充四個(ge)(ge)小(xiao)時(shi)(shi)(shi).這種(zhong)結果(guo)往(wang)往(wang)會對電(dian)(dian)(dian)(dian)池 造(zao)成損壞。因此(ci)(ci)原因,定(ding)時(shi)(shi)(shi)充電(dian)(dian)(dian)(dian)器(qi)(qi)很少被采用(yong)。）

充電時可充電池應備條件

當(dang)(dang)電池連接上(shang)充電器以(yi)后,此(ci)充電階段之充電器要能夠有所感(gan)應(ying)顯示以(yi)及(ji)彼電池是否可以(yi)進(jin)行充電.一般當(dang)(dang)充電器電源關斷 的情況下,此(ci)電池感(gan)應(ying)裝置通常根據(ju)充電器接頭的端口電壓(ya)(ya)來進(jin)行判斷,但當(dang)(dang)電池已經反復過度使用或(huo)端口電壓(ya)(ya)極低的情況下, 這種(zhong)感(gan)應(ying)裝置往往會產生問(wen)題.作為(wei)一種(zhong)替(ti)代(dai)方法,充電器經常根據(ju)溫度或(huo)電壓(ya)(ya)瞬時跳變來達到上(shang)述(shu)目的.這種(zhong)硬(ying)件(jian)設置同樣適 用于電池組.

一(yi)(yi)旦(dan)充(chong)電(dian)(dian)(dian)(dian)器(qi)感應連(lian)接(jie)到了(le)可充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)池,它還必須判斷(duan)出(chu)電(dian)(dian)(dian)(dian)池是(shi)否具備良(liang)好可充(chong)條(tiao)件(jian).在這(zhe)個次級階(jie)段(duan)[限定(ding)條(tiao)件(jian)],電(dian)(dian)(dian)(dian)池要能夠 被檢(jian)測(ce)出(chu)其(qi)(qi)基本(ben)功能狀態;開路,短路,高溫或是(shi)低溫.以此來檢(jian)測(ce)電(dian)(dian)(dian)(dian)池是(shi)否具備可充(chong)性,一(yi)(yi)些鉛(qian)酸充(chong)電(dian)(dian)(dian)(dian)器(qi)類(lei)型特別需要一(yi)(yi)個可通過(guo) LED燈來顯示出(chu)其(qi)(qi)充(chong)電(dian)(dian)(dian)(dian)的(de)(de)主充(chong)電(dian)(dian)(dian)(dian)流(liu)[大約以五分(fen)之一(yi)(yi)的(de)(de)快充(chong)額(e)定(ding)電(dian)(dian)(dian)(dian)流(liu)],并(bing)允許電(dian)(dian)(dian)(dian)池在一(yi)(yi)固定(ding)充(chong)電(dian)(dian)(dian)(dian)時間段(duan)內達到其(qi)(qi)特定(ding)的(de)(de)電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓. 這(zhe)種技術對已經(jing)反(fan)復(fu)過(guo)度使(shi)用的(de)(de)鉛(qian)酸[PbSO4]蓄電(dian)(dian)(dian)(dian)池,應避免出(chu)現反(fan)接(jie)的(de)(de)問題.

對外圍設備和(he)電(dian)(dian)(dian)(dian)池(chi)溫(wen)度的檢(jian)測(ce)也是本(ben)階段(duan)必要條件之一.當充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器檢(jian)測(ce)到電(dian)(dian)(dian)(dian)池(chi)的溫(wen)度過(guo)高或過(guo)低,一般(ban)會等(deng)待(dai)一段(duan)預先(xian)設定(ding)(ding)的 時間以使其恢(hui)復正常(chang).如在設定(ding)(ding)時間內并未(wei)恢(hui)復正常(chang),充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器會自動改變充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流,這(zhe)個動作相應就(jiu)(jiu)調整了電(dian)(dian)(dian)(dian)池(chi)溫(wen)度,所(suo)(suo)以充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)效(xiao)率 會大(da)大(da)增(zeng)加.最后,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器需要檢(jian)測(ce)一下與電(dian)(dian)(dian)(dian)池(chi)的連接(jie)狀態是開(kai)路抑或短路.通(tong)常(chang)開(kai)路狀態容易檢(jian)測(ce),而(er)一旦出現(xian)短路顯示(shi),就(jiu)(jiu)需要進 一步確認,以避免造成事故的發生.如果所(suo)(suo)有檢(jian)測(ce)都(dou)獲得通(tong)過(guo),就(jiu)(jiu)可以給電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)了.這(zhe)種(zhong)設置相當領先(xian),請參閱附圖1

預先充電條件設置[自選類型]

有一(yi)(yi)些(xie)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)[如早期出(chu)現的(de)(de)鎳鎘電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)]都設(she)計有一(yi)(yi)個(ge)(ge)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)前(qian)期預測(ce)階段(duan),用以判斷在重新充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)前(qian)，待測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)是否已‘完全’放電(dian)(dian)(dian)(dian)(dian)(dian). 所謂‘完全’放電(dian)(dian)(dian)(dian)(dian)(dian)系指每節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)端(duan)口電(dian)(dian)(dian)(dian)(dian)(dian)壓放電(dian)(dian)(dian)(dian)(dian)(dian)到1V的(de)(de)水平,以去除電(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)液中的(de)(de)枝狀(zhuang)(zhuang)(zhuang)結構,這也(ye)是人們為(wei)什么經(jing)常錯誤(wu)地理解(jie)(jie)‘記憶(yi) 效(xiao)應(ying)’的(de)(de)原因(yin)[通常電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)一(yi)(yi)次(ci)可(ke)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)容量是上次(ci)放電(dian)(dian)(dian)(dian)(dian)(dian)容量的(de)(de)104—110百(bai)分比].這種所謂的(de)(de)‘記憶(yi)效(xiao)應(ying)’特指電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)內部電(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)液枝狀(zhuang)(zhuang)(zhuang)結 構狀(zhuang)(zhuang)(zhuang)態(tai)的(de)(de)自我恢復能力,如受到破壞,將減少電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)使用壽命.所以按(an)正常時間周期進行的(de)(de)充(chong)(chong)放電(dian)(dian)(dian)(dian)(dian)(dian),往往會解(jie)(jie)決這個(ge)(ge)問題(ti).

在每次充電(dian)前,此預測階(jie)段(duan)都會被自(zi)動完成(cheng),或在電(dian)池(chi)充電(dian)剩余(yu)過(guo)(guo)半顯示[通過(guo)(guo)連接測試(shi)或其它(ta)操作]之后.預測階(jie)段(duan)一(yi)般從(cong)一(yi)到十小 時不等.在一(yi)小時之內放空電(dian)池(chi)通常不予考慮.而(er)(er)通過(guo)(guo)連接電(dian)阻(zu)縮短預測階(jie)段(duan)時間,會產生散熱(re)困難的(de)問題(ti).而(er)(er)大于十小時的(de)階(jie)段(duan)設計 也(ye)往(wang)往(wang)不被采用,除非可以(yi)用手動方式開始探測減少的(de)電(dian)池(chi)容量.因此,由于對鎳鎘電(dian)池(chi)’記(ji)憶效應(ying)’的(de)不知和種種誤解(jie),設計人員應(ying) 避免在充電(dian)器上設置相關(guan)按(an)鈕來(lai)與此’效應(ying)’進行對抗.

快充階段及充電終止

快充(chong)和終止充(chong)電方式使(shi)(shi)用要根據(ju)蓄電池(chi)及(ji)其它設計因素考慮.以(yi)下探討涉及(ji)到當今通用蓄電池(chi)快充(chong)技術(shu)的(de)全(quan)面使(shi)(shi)用.如需(xu)詳細建 議資料,可與電池(chi)制造商(shang)應用部門(men)聯系查詢.

鎳鎘,鎳氫蓄電池

鎳(nie)鎘和鎳(nie)氫蓄電(dian)(dian)池(chi)的快(kuai)充(chong)(chong)(chong)程序(xu)非常(chang)類似,主要區別在于(yu)充(chong)(chong)(chong)電(dian)(dian)的終止階段.在每(mei)一(yi)個樣例中,當充(chong)(chong)(chong)電(dian)(dian)器(qi)監測電(dian)(dian)池(chi)電(dian)(dian)壓及其它數據,以 判斷何時終止充(chong)(chong)(chong)電(dian)(dian)時,都(dou)需(xu)要一(yi)個恒定電(dian)(dian)流.超過2C的充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流是可以做到的,但(dan)一(yi)般最(zui)常(chang)用(yong)C/2左右的電(dian)(dian)流.因充(chong)(chong)(chong)電(dian)(dian)效率(lv)無論怎樣都(dou) 要小(xiao)于(yu)100%, 所(suo)以用(yong)C/2電(dian)(dian)流稍多于(yu)兩個小(xiao)時的全充(chong)(chong)(chong)是可以被接(jie)受的.

在恒流(liu)充(chong)(chong)電(dian)(dian)階段,電(dian)(dian)池端口電(dian)(dian)壓(ya)緩(huan)慢上升,最(zui)終(zhong)到(dao)達頂點(dian)[即坡度(du)為零的電(dian)(dian)壓(ya)最(zui)高點(dian)].鎳氫電(dian)(dian)池應在此點(dian)[0DV點(dian)]終(zhong)止充(chong)(chong)電(dian)(dian).而鎳鎘(ge) 電(dian)(dian)池則應在此點(dian)之后(hou)某點(dian)[系電(dian)(dian)池端口電(dian)(dian)壓(ya)首次出現(xian)微(wei)小降低點(dian)即-DV點(dian)]結(jie)束,請參(can)閱圖2,可允許有少部分過充(chong)(chong).快充(chong)(chong)如超(chao)過這兩個設(she) 定關(guan)斷點(dian)[最(zui)高電(dian)(dian)壓(ya)點(dian)和略(lve)小的-DV點(dian)],都(dou)會對電(dian)(dian)池造成損壞.這是因為快充(chong)(chong)電(dian)(dian)流(liu)遠大于正常慢充(chong)(chong)狀態所致.

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(yu)C/2電(dian)(dian)(dian)(dian)(dian)流(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)[充(chong)電(dian)(dian)(dian)(dian)(dian)時間不會超過兩個小(xiao)時],充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)仍要監(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)池(chi)溫(wen)(wen)度(du)和(he)電(dian)(dian)(dian)(dian)(dian)壓.因(yin)為當電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)滿時,電(dian)(dian)(dian)(dian)(dian)池(chi)溫(wen)(wen)度(du)將上升很快,所(suo)以 溫(wen)(wen)度(du)監(jian)測(ce)元件要啟動(dong)另一關(guan)(guan)斷(duan)(duan)(duan)(duan)裝(zhuang)置.在這正(zheng)向上升溫(wen)(wen)度(du)曲(qu)線上的(de)關(guan)(guan)斷(duan)(duan)(duan)(duan)點(dian)被稱為T關(guan)(guan)斷(duan)(duan)(duan)(duan)點(dian).除溫(wen)(wen)度(du)關(guan)(guan)斷(duan)(duan)(duan)(duan)外,其它監(jian)測(ce)數據(ju),包括已充(chong)時間,最 大(da)限定電(dian)(dian)(dian)(dian)(dian)池(chi)保護電(dian)(dian)(dian)(dian)(dian)壓,都可(ke)參預充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)關(guan)(guan)斷(duan)(duan)(duan)(duan).所(suo)以設計成功的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)自動(dong)關(guan)(guan)斷(duan)(duan)(duan)(duan)應依據(ju)這幾種監(jian)測(ce)因(yin)素[溫(wen)(wen)度(du)關(guan)(guan)斷(duan)(duan)(duan)(duan),充(chong)電(dian)(dian)(dian)(dian)(dian)時間關(guan)(guan)斷(duan)(duan)(duan)(duan),電(dian)(dian)(dian)(dian)(dian)池(chi)最大(da) 限定電(dian)(dian)(dian)(dian)(dian)壓關(guan)(guan)斷(duan)(duan)(duan)(duan)等]的(de)組合.

備注;當電(dian)(dian)池首次(ci)充(chong)電(dian)(dian),會(hui)產(chan)生模仿關(guan)斷(duan)狀態(tai)(tai)的(de)(de)(de)特定(ding)效應,因此在激活關(guan)斷(duan)模式監(jian)測曲線前(qian),充(chong)電(dian)(dian)器會(hui)引(yin)入一(yi)個(ge) 一(yi)到五分(fen)鐘的(de)(de)(de)緩沖期.另外,充(chong)電(dian)(dian)關(guan)斷(duan)狀態(tai)(tai)在低(di)于C\8電(dian)(dian)流充(chong)電(dian)(dian)時(shi)很(hen)難監(jian)測到數(shu)據,這(zhe)是因為與(yu)其他系(xi)統(tong)數(shu)據比較, 電(dian)(dian)壓(ya)和(he)溫度曲線[V/t和(he)T/t]斜(xie)率很(hen)小所致.為快速充(chong)電(dian)(dian)的(de)(de)(de)安全起(qi)見,這(zhe)些系(xi)統(tong)中的(de)(de)(de)硬(ying)軟件(jian)配置總是會(hui)造成充(chong)電(dian)(dian)器提(ti) 前(qian)關(guan)斷(duan)的(de)(de)(de)誤操(cao)作動(dong)作.

 

鋰離子電池

鋰離子蓄(xu)電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)曲線和鎳離子蓄(xu)電(dian)(dian)(dian)池相比很不一樣.充(chong)電(dian)(dian)(dian)關(guan)斷要(yao)(yao)確(que)定(ding)(ding)到(dao)最大安全值(zhi)之后(hou)才會動作(zuo).鋰電(dian)(dian)(dian)充(chong)電(dian)(dian)(dian)器要(yao)(yao)將(jiang)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓控制(zhi) 在小(xiao)于0.75%的(de)精確(que)范圍內(nei),并且其最大充(chong)電(dian)(dian)(dian)效率用充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)限定(ding)(ding)控制(zhi),非常類似臺式桌(zhuo)面型直流(liu)(liu)電(dian)(dian)(dian)源. 當(dang)快充(chong)開始時,電(dian)(dian)(dian)池端口電(dian)(dian)(dian)壓相 對(dui)較低,充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)就等同(tong)于其限定(ding)(ding)電(dian)(dian)(dian)流(liu)(liu)值(zhi).

在充(chong)電(dian)過程中,電(dian)池電(dian)壓(ya)緩慢上升.最后,充(chong)電(dian)電(dian)流(liu)到達設定峰值,充(chong)電(dian)電(dian)壓(ya)上升到每節 4.2V的浮充(chong)電(dian)壓(ya)水(shui)平[見圖(tu)4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)到浮充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)壓水平(ping),充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)就可(ke)以終止充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)了(le),但這種(zhong)方(fang)式忽略了(le)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)峰頂值(zhi)關(guan)(guan)(guan)斷操作.如在(zai)浮充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)壓階(jie)段,充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)會開始(shi) 定(ding)時器(qi)(qi)的(de)(de)操作,在(zai)一(yi)段設(she)定(ding)緩沖期(qi)后,自動終止充(chong)(chong)電(dian)(dian)(dian)(dian)(dian).另一(yi)方(fang)式,也(ye)(ye)可(ke)監測充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu),在(zai)一(yi)個較低電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)水平(ping)關(guan)(guan)(guan)斷[典型(xing)地用(yong)0.05的(de)(de)限定(ding)值(zhi), 一(yi)些制造(zao)商建(jian)議使用(yong)相對較高(gao)的(de)(de)100mA電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)最小值(zhi)].充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)峰值(zhi)關(guan)(guan)(guan)斷環路往往也(ye)(ye)依靠這種(zhong)技術(shu).

最近幾年,在鋰離(li)子(zi)(zi)電池(chi)和其(qi)充(chong)電器,以及對這(zhe)種新(xin)型電池(chi)的(de)(de)(de)了(le)(le)解方面,都(dou)取得了(le)(le)相當(dang)的(de)(de)(de)進展.最早期的(de)(de)(de)鋰離(li)子(zi)(zi)電池(chi)在用戶(hu)的(de)(de)(de)使用方 面都(dou)有(you)一些安全(quan)層面的(de)(de)(de)缺點,而這(zhe)些問題已不會出現在當(dang)今設計成功的(de)(de)(de)系(xi)統(tong)上(shang)了(le)(le).制(zhi)造(zao)商們的(de)(de)(de)建議既(ji)不會一成不變,也不會完全(quan)一致, 而鋰離(li)子(zi)(zi)電池(chi)技術會繼續向前發(fa)展.

鋰(li)聚(ju)合物電池(chi)(chi)的充(chong)電要求(qiu)(qiu)和鋰(li)離(li)子電池(chi)(chi)的要求(qiu)(qiu)是一樣的，可以按同類對(dui)待。

最(zui)新(xin)出現的磷酸鐵鋰(li)電(dian)池的電(dian)壓(ya)(ya)比鋰(li)離子(zi)電(dian)池的額度(du)電(dian)壓(ya)(ya)要低0.4V左右，充電(dian)的恒壓(ya)(ya)電(dian)壓(ya)(ya)設定值(zhi)為(wei)3.7V/節為(wei)宜。充電(dian)的方式與 鋰(li)離子(zi)電(dian)池基本相(xiang)同（注意只(zhi)是(shi)電(dian)壓(ya)(ya)要低一些！）

 

鉛酸電池.

鉛酸[PbSO4]蓄電(dian)(dian)池既可以用(yong)(yong)限(xian)流充(chong)(chong)電(dian)(dian),也可以用(yong)(yong)較通用(yong)(yong)簡單(dan)的(de)限(xian)壓(ya)充(chong)(chong)電(dian)(dian).限(xian)壓(ya)充(chong)(chong)電(dian)(dian)與前者(zhe)具有類似的(de)作用(yong)(yong)功能(neng),而高精確性并非是 其關鍵(jian).這需要設置一(yi)個高于(yu)電(dian)(dian)池浮充(chong)(chong)電(dian)(dian)壓(ya)的(de)限(xian)流電(dian)(dian)壓(ya)源[大(da)約(yue)2.45V左右].

經(jing)過預設狀(zhuang)態操作,充(chong)電(dian)(dian)(dian)器確認開始快(kuai)充(chong),一直延續到最小充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流[這個過程類似鋰離子(zi)電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)器],然后快(kuai)充(chong)終止.這時充(chong)電(dian)(dian)(dian)器 需要(yao)一段(duan)Vf浮充(chong)電(dian)(dian)(dian)壓進行(xing)維(wei)護(hu)[通常(chang)用(yong)(yong)2.25V左(zuo)右電(dian)(dian)(dian)壓].鉛酸[PbSO4]蓄電(dian)(dian)(dian)池(chi)允許在非確定階段(duan)用(yong)(yong)此浮充(chong)電(dian)(dian)(dian)壓進行(xing)維(wei)護(hu)[見(jian)圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高溫(wen)環(huan)境下,對鉛(qian)酸[PbSO4]蓄電(dian)池進(jin)行快充(chong)的電(dian)流要根據每攝氏度(du)0.3百(bai)分比的標準溫(wen)度(du)系數進(jin)行調低(di).快充(chong)時(shi)設定最大電(dian)池溫(wen)度(du) 建議在50’C左右,但浮充(chong)一般可以超過這個溫(wen)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]

除鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)(chi)外,其(qi)它蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)器(qi)經(jing)(jing)常(chang)設置有(you)一個可(ke)供(gong)選(xuan)擇的(de)涓流(liu)充(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan).這個階(jie)段(duan)的(de)設置可(ke)以用(yong)來(lai)(lai)補(bu)償電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)滿后本(ben)體的(de)自放電(dian)(dian)(dian)(dian) 現(xian)象.鉛酸(suan)[PbSO4]電(dian)(dian)(dian)(dian)池(chi)(chi)自放電(dian)(dian)(dian)(dian)率最大[每天呈數個百分點],而(er)鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)(chi)最低.鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)自放電(dian)(dian)(dian)(dian)率有(you)時低到已無需(xu)涓充(chong)來(lai)(lai)維(wei)護(hu).然而(er), 鎳(nie)鎘[NiCds]蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)卻經(jing)(jing)常(chang),不(bu)定地需(xu)要C/16的(de)涓充(chong)電(dian)(dian)(dian)(dian)流(liu)以進行維(wei)護(hu).對鎳(nie)氫[NiMH]蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)而(er)言(yan),安(an)全(quan)的(de)持續放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)經(jing)(jing)常(chang)在C/50左(zuo)右,而(er)涓 流(liu)充(chong)電(dian)(dian)(dian)(dian)一般(ban)不(bu)被建議.

續放電(dian)電(dian)流經常(chang)在C/50左右,而涓 流充電(dian)一般不被建議(yi).