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(er)恒壓(ya) 充(chong)電方(fang)法在充(chong)電初期(qi)電池內阻極低致使充(chong)電電流過大，而(er)隨時間并不按指數規律(lv)下降常(chang)偏離(li)制(zhi)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(de)任意(yi)時刻總 存(cun)在一個(ge)最佳的(de)充電(dian)電(dian)流和充電(dian)模式的(de)，問題(ti)是我們如何才能逼近(jin)這個(ge)最佳值(zhi)。 

綜合起來(lai)，判斷規則有如下幾種：

●定時控制；

●電(dian)壓(ya)控(kong)制(zhi)(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(包括最高溫度，最高溫升：溫度變化率(lv)等(deng))；

●電流控制等。

較好(hao)的辦法是采用(yong)綜合判斷方法，對每個指標進行跟蹤(zong)，并(bing)按(an)模糊數學(xue)原理分(fen)別記(ji)分(fen)，按(an)照置信度做出最佳判斷。 電池快速充電分(fen)為幾個階段,見(jian)本文(wen)所述及(ji)通用(yong)充電器運行簡圖.[圖1]

　

 

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

 

起始階段

起始階(jie)段(duan)在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)中雖(sui)不(bu)(bu)屬于真正起作用(yong)的(de)(de)(de)那幾(ji)個階(jie)段(duan),但在(zai)整個充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)中,起始階(jie)段(duan)仍是一(yi)個非(fei)常重(zhong)要(yao)的(de)(de)(de)滿足條件. 充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)啟動(dong)以(yi)后開始自(zi)測,如(ru)(ru)電(dian)(dian)(dian)(dian)源(yuan)出現故(gu)(gu)障或(huo)反復(fu)起動(dong),充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)就會(hui)被(bei)打斷(duan).如(ru)(ru)果(guo)缺乏相應(ying)智能或(huo)時(shi)間關斷(duan)裝置以(yi)及電(dian)(dian)(dian)(dian)池(chi)密 封性(xing)能不(bu)(bu)能得到改善,那么此種(zhong)現象往往會(hui)被(bei)忽(hu)視.幾(ji)乎(hu)所有的(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)在(zai)電(dian)(dian)(dian)(dian)源(yuan)出現故(gu)(gu)障以(yi)后都可(ke)以(yi)完全重(zhong)新啟動(dong),但如(ru)(ru)過(guo)(guo)充(chong)(chong)(chong)不(bu)(bu) 被(bei)允許,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)要(yao)能夠(gou)進行特(te)別的(de)(de)(de)自(zi)測程(cheng)序以(yi)判(pan)斷(duan)電(dian)(dian)(dian)(dian)池(chi)是否早(zao)已(yi)充(chong)(chong)(chong)滿.電(dian)(dian)(dian)(dian)池(chi)狀態(tai)要(yao)顯現在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)指(zhi)示燈或(huo)類似的(de)(de)(de)顯示裝置上. （不(bu)(bu)好的(de)(de)(de)案例：例如(ru)(ru)只靠定(ding)(ding)時(shi)的(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi),用(yong)四個小(xiao)時(shi)間隔的(de)(de)(de)固(gu)定(ding)(ding)時(shi)間給電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian).如(ru)(ru)果(guo)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)三(san)小(xiao)時(shi)59分鐘,電(dian)(dian)(dian)(dian)源(yuan)出現故(gu)(gu)障斷(duan)電(dian)(dian)(dian)(dian), 當故(gu)(gu)障清除重(zhong)新送電(dian)(dian)(dian)(dian)以(yi)后,充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)又會(hui)開始重(zhong)新一(yi)輪的(de)(de)(de)四小(xiao)時(shi)固(gu)定(ding)(ding)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian),從(cong)而造成電(dian)(dian)(dian)(dian)池(chi)過(guo)(guo)充(chong)(chong)(chong)四個小(xiao)時(shi).這種(zhong)結果(guo)往往會(hui)對電(dian)(dian)(dian)(dian)池(chi) 造成損(sun)壞。因此原因,定(ding)(ding)時(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)很少被(bei)采用(yong)。）

充電時可充電池應備條件

當電(dian)(dian)池(chi)(chi)連(lian)接上充(chong)(chong)電(dian)(dian)器(qi)(qi)(qi)以后(hou),此(ci)(ci)充(chong)(chong)電(dian)(dian)階段(duan)之充(chong)(chong)電(dian)(dian)器(qi)(qi)(qi)要能夠(gou)有所感應(ying)顯(xian)示以及(ji)彼(bi)電(dian)(dian)池(chi)(chi)是否(fou)可以進行(xing)充(chong)(chong)電(dian)(dian).一般(ban)當充(chong)(chong)電(dian)(dian)器(qi)(qi)(qi)電(dian)(dian)源關斷(duan) 的(de)情況(kuang)下(xia),此(ci)(ci)電(dian)(dian)池(chi)(chi)感應(ying)裝置通常根(gen)據(ju)充(chong)(chong)電(dian)(dian)器(qi)(qi)(qi)接頭的(de)端(duan)口(kou)電(dian)(dian)壓(ya)來(lai)(lai)進行(xing)判斷(duan),但(dan)當電(dian)(dian)池(chi)(chi)已經反復過度使用或端(duan)口(kou)電(dian)(dian)壓(ya)極低的(de)情況(kuang)下(xia), 這種(zhong)感應(ying)裝置往(wang)往(wang)會產生問題.作為一種(zhong)替代方(fang)法,充(chong)(chong)電(dian)(dian)器(qi)(qi)(qi)經常根(gen)據(ju)溫(wen)度或電(dian)(dian)壓(ya)瞬時跳變來(lai)(lai)達(da)到上述目的(de).這種(zhong)硬件設置同樣(yang)適 用于電(dian)(dian)池(chi)(chi)組.

一(yi)旦充(chong)電(dian)(dian)(dian)器(qi)感應連(lian)接到(dao)(dao)了(le)可充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池,它還必須(xu)判斷出(chu)電(dian)(dian)(dian)池是否(fou)(fou)具(ju)備良(liang)好可充(chong)條件(jian).在這(zhe)個(ge)次級(ji)階段(duan)[限(xian)定(ding)條件(jian)],電(dian)(dian)(dian)池要(yao)能(neng)夠 被檢測出(chu)其(qi)基(ji)本功能(neng)狀態;開路,短路,高溫或是低溫.以此來(lai)檢測電(dian)(dian)(dian)池是否(fou)(fou)具(ju)備可充(chong)性(xing),一(yi)些鉛酸(suan)充(chong)電(dian)(dian)(dian)器(qi)類型特別需要(yao)一(yi)個(ge)可通(tong)過 LED燈來(lai)顯示(shi)出(chu)其(qi)充(chong)電(dian)(dian)(dian)的(de)(de)主充(chong)電(dian)(dian)(dian)流(liu)[大約以五分之一(yi)的(de)(de)快充(chong)額(e)定(ding)電(dian)(dian)(dian)流(liu)],并允許電(dian)(dian)(dian)池在一(yi)固定(ding)充(chong)電(dian)(dian)(dian)時間段(duan)內達到(dao)(dao)其(qi)特定(ding)的(de)(de)電(dian)(dian)(dian)池電(dian)(dian)(dian)壓. 這(zhe)種技術(shu)對已經反復過度使用的(de)(de)鉛酸(suan)[PbSO4]蓄電(dian)(dian)(dian)池,應避免出(chu)現反接的(de)(de)問題.

對外圍設備和(he)電(dian)(dian)(dian)(dian)(dian)池(chi)溫度的(de)(de)檢(jian)測(ce)(ce)也是本階段必要(yao)條(tiao)件(jian)之一(yi)(yi).當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)檢(jian)測(ce)(ce)到電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)溫度過(guo)高或過(guo)低,一(yi)(yi)般(ban)會等待一(yi)(yi)段預先設定的(de)(de) 時(shi)間以(yi)使其(qi)恢復正常(chang).如在設定時(shi)間內并(bing)未恢復正常(chang),充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)會自動改(gai)變充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流,這個(ge)動作相(xiang)應就(jiu)(jiu)調整了電(dian)(dian)(dian)(dian)(dian)池(chi)溫度,所(suo)以(yi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)效(xiao)率 會大大增加.最后,充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)需要(yao)檢(jian)測(ce)(ce)一(yi)(yi)下(xia)與電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)連(lian)接(jie)狀態是開路抑或短路.通常(chang)開路狀態容易檢(jian)測(ce)(ce),而一(yi)(yi)旦出現短路顯示,就(jiu)(jiu)需要(yao)進 一(yi)(yi)步確認(ren),以(yi)避免造成事(shi)故(gu)的(de)(de)發生.如果所(suo)有檢(jian)測(ce)(ce)都獲得(de)通過(guo),就(jiu)(jiu)可以(yi)給電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)了.這種(zhong)設置相(xiang)當(dang)領先,請(qing)參(can)閱附圖1

預先充電條件設置[自選類型]

有(you)一些充(chong)(chong)(chong)電(dian)器[如早期(qi)出現(xian)的(de)鎳鎘電(dian)池]都設計有(you)一個充(chong)(chong)(chong)電(dian)前期(qi)預測階段(duan),用以判斷(duan)在重新充(chong)(chong)(chong)電(dian)前，待測電(dian)池是否已‘完全’放(fang)(fang)電(dian). 所(suo)謂‘完全’放(fang)(fang)電(dian)系指每(mei)節(jie)電(dian)池的(de)端口電(dian)壓放(fang)(fang)電(dian)到(dao)1V的(de)水(shui)平,以去除電(dian)解液(ye)中的(de)枝狀(zhuang)結構,這(zhe)也(ye)是人(ren)們為(wei)什么經常(chang)錯誤地理解‘記(ji)憶(yi) 效應(ying)’的(de)原(yuan)因[通(tong)常(chang)電(dian)池一次可充(chong)(chong)(chong)電(dian)容(rong)量(liang)是上次放(fang)(fang)電(dian)容(rong)量(liang)的(de)104—110百分比].這(zhe)種(zhong)所(suo)謂的(de)‘記(ji)憶(yi)效應(ying)’特指電(dian)池內部電(dian)解液(ye)枝狀(zhuang)結 構狀(zhuang)態的(de)自(zi)我(wo)恢復能力,如受到(dao)破壞(huai),將(jiang)減少電(dian)池的(de)使用壽命.所(suo)以按正常(chang)時間周期(qi)進(jin)行的(de)充(chong)(chong)(chong)放(fang)(fang)電(dian),往往會解決這(zhe)個問(wen)題.

在(zai)每次充電(dian)前,此預(yu)測階段都會被自動完成(cheng),或在(zai)電(dian)池充電(dian)剩余過(guo)半(ban)顯示[通過(guo)連接(jie)測試或其它操作]之(zhi)后.預(yu)測階段一(yi)(yi)般從一(yi)(yi)到十小 時(shi)不(bu)(bu)(bu)等(deng).在(zai)一(yi)(yi)小時(shi)之(zhi)內放(fang)空電(dian)池通常不(bu)(bu)(bu)予考(kao)慮.而通過(guo)連接(jie)電(dian)阻(zu)縮短(duan)預(yu)測階段時(shi)間,會產(chan)生散熱困難的(de)問題.而大于(yu)十小時(shi)的(de)階段設計 也往往不(bu)(bu)(bu)被采用,除非可以用手動方式開始探測減少的(de)電(dian)池容(rong)量(liang).因此,由于(yu)對鎳(nie)鎘電(dian)池’記(ji)憶效(xiao)應’的(de)不(bu)(bu)(bu)知和種種誤解,設計人(ren)員應 避免在(zai)充電(dian)器上設置(zhi)相關按(an)鈕來與此’效(xiao)應’進行(xing)對抗.

快充階段及充電終止

快充(chong)和終止充(chong)電(dian)(dian)方式使用(yong)要根據蓄電(dian)(dian)池及其它(ta)設計因素考(kao)慮(lv).以(yi)下探討涉及到當今通用(yong)蓄電(dian)(dian)池快充(chong)技術(shu)的全(quan)面使用(yong).如需詳細(xi)建(jian) 議(yi)資料,可(ke)與(yu)電(dian)(dian)池制造商應用(yong)部門聯(lian)系查詢(xun).

鎳鎘,鎳氫蓄電池

鎳鎘和鎳氫(qing)蓄電(dian)(dian)池(chi)的(de)(de)(de)快(kuai)充(chong)(chong)程序非(fei)常(chang)類似,主要(yao)(yao)區(qu)別(bie)在于(yu)充(chong)(chong)電(dian)(dian)的(de)(de)(de)終止階(jie)段(duan).在每(mei)一個(ge)樣(yang)例(li)中(zhong),當充(chong)(chong)電(dian)(dian)器監(jian)測電(dian)(dian)池(chi)電(dian)(dian)壓(ya)及其它數據,以 判斷何時終止充(chong)(chong)電(dian)(dian)時,都需(xu)要(yao)(yao)一個(ge)恒定電(dian)(dian)流.超(chao)過(guo)2C的(de)(de)(de)充(chong)(chong)電(dian)(dian)電(dian)(dian)流是可(ke)(ke)以做到(dao)的(de)(de)(de),但一般最常(chang)用(yong)C/2左右的(de)(de)(de)電(dian)(dian)流.因充(chong)(chong)電(dian)(dian)效率(lv)無論怎樣(yang)都 要(yao)(yao)小于(yu)100%, 所以用(yong)C/2電(dian)(dian)流稍多(duo)于(yu)兩個(ge)小時的(de)(de)(de)全充(chong)(chong)是可(ke)(ke)以被接受的(de)(de)(de).

在恒(heng)流(liu)充電(dian)(dian)(dian)(dian)(dian)階段,電(dian)(dian)(dian)(dian)(dian)池(chi)端(duan)口(kou)電(dian)(dian)(dian)(dian)(dian)壓(ya)緩慢上升(sheng),最(zui)終到達頂(ding)點(dian)[即坡度(du)為零的電(dian)(dian)(dian)(dian)(dian)壓(ya)最(zui)高(gao)(gao)點(dian)].鎳氫電(dian)(dian)(dian)(dian)(dian)池(chi)應在此點(dian)[0DV點(dian)]終止充電(dian)(dian)(dian)(dian)(dian).而(er)鎳鎘 電(dian)(dian)(dian)(dian)(dian)池(chi)則應在此點(dian)之后某點(dian)[系電(dian)(dian)(dian)(dian)(dian)池(chi)端(duan)口(kou)電(dian)(dian)(dian)(dian)(dian)壓(ya)首次出(chu)現(xian)微小降低點(dian)即-DV點(dian)]結束,請參(can)閱圖2,可允(yun)許有(you)少部(bu)分過(guo)充.快充如超過(guo)這兩個(ge)設 定關斷點(dian)[最(zui)高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)壓(ya)點(dian)和略小的-DV點(dian)],都會對電(dian)(dian)(dian)(dian)(dian)池(chi)造成損壞.這是因為快充電(dian)(dian)(dian)(dian)(dian)流(liu)遠大于正常(chang)慢充狀(zhuang)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)(da)于C/2電流充(chong)(chong)(chong)(chong)電[充(chong)(chong)(chong)(chong)電時(shi)(shi)間(jian)不(bu)會超過兩個小時(shi)(shi)],充(chong)(chong)(chong)(chong)電器(qi)仍要監測(ce)電池(chi)溫(wen)(wen)(wen)度(du)和電壓.因為當電池(chi)充(chong)(chong)(chong)(chong)滿時(shi)(shi),電池(chi)溫(wen)(wen)(wen)度(du)將上升(sheng)(sheng)很快,所以 溫(wen)(wen)(wen)度(du)監測(ce)元件要啟動另一(yi)關(guan)(guan)斷(duan)(duan)(duan)裝置(zhi).在(zai)這正(zheng)向上升(sheng)(sheng)溫(wen)(wen)(wen)度(du)曲(qu)線(xian)上的關(guan)(guan)斷(duan)(duan)(duan)點被稱為T關(guan)(guan)斷(duan)(duan)(duan)點.除(chu)溫(wen)(wen)(wen)度(du)關(guan)(guan)斷(duan)(duan)(duan)外,其(qi)它監測(ce)數據,包括已充(chong)(chong)(chong)(chong)時(shi)(shi)間(jian),最(zui) 大(da)(da)限定(ding)電池(chi)保護電壓,都可參預充(chong)(chong)(chong)(chong)電器(qi)關(guan)(guan)斷(duan)(duan)(duan).所以設計(ji)成功的充(chong)(chong)(chong)(chong)電器(qi)自動關(guan)(guan)斷(duan)(duan)(duan)應依據這幾種(zhong)監測(ce)因素[溫(wen)(wen)(wen)度(du)關(guan)(guan)斷(duan)(duan)(duan),充(chong)(chong)(chong)(chong)電時(shi)(shi)間(jian)關(guan)(guan)斷(duan)(duan)(duan),電池(chi)最(zui)大(da)(da) 限定(ding)電壓關(guan)(guan)斷(duan)(duan)(duan)等]的組合.

備注(zhu);當電池首次(ci)充電,會產生模仿(fang)關(guan)(guan)斷狀態(tai)的特定效應,因此在激活(huo)關(guan)(guan)斷模式監(jian)測曲(qu)線前,充電器(qi)會引入(ru)一個 一到五(wu)分鐘的緩沖(chong)期.另外,充電關(guan)(guan)斷狀態(tai)在低于C\8電流充電時很難監(jian)測到數據,這是因為與其(qi)他系統(tong)數據比(bi)較, 電壓和溫度曲(qu)線[V/t和T/t]斜率很小所致.為快(kuai)速充電的安全起見,這些系統(tong)中的硬軟件配置總是會造成(cheng)充電器(qi)提(ti) 前關(guan)(guan)斷的誤(wu)操作動作.

 

鋰離子電池

鋰(li)離子(zi)蓄電(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)曲線和鎳離子(zi)蓄電(dian)(dian)池(chi)(chi)相(xiang)比很(hen)不一(yi)樣(yang).充(chong)電(dian)(dian)關(guan)斷要(yao)確(que)定(ding)到最(zui)大(da)安(an)全值之后(hou)才會動作.鋰(li)電(dian)(dian)充(chong)電(dian)(dian)器要(yao)將充(chong)電(dian)(dian)電(dian)(dian)壓(ya)控制 在小于(yu)0.75%的精確(que)范圍(wei)內,并(bing)且其最(zui)大(da)充(chong)電(dian)(dian)效(xiao)率用充(chong)電(dian)(dian)電(dian)(dian)流(liu)限定(ding)控制,非常類似臺(tai)式桌面型(xing)直流(liu)電(dian)(dian)源. 當快充(chong)開始時,電(dian)(dian)池(chi)(chi)端口電(dian)(dian)壓(ya)相(xiang) 對較低,充(chong)電(dian)(dian)電(dian)(dian)流(liu)就等同于(yu)其限定(ding)電(dian)(dian)流(liu)值.

在充電(dian)(dian)過程中,電(dian)(dian)池電(dian)(dian)壓緩慢上(shang)升(sheng)(sheng).最(zui)后,充電(dian)(dian)電(dian)(dian)流到達設定峰值,充電(dian)(dian)電(dian)(dian)壓上(shang)升(sheng)(sheng)到每節 4.2V的浮充電(dian)(dian)壓水平[見圖4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)池充(chong)(chong)電(dian)到浮充(chong)(chong)電(dian)壓水平,充(chong)(chong)電(dian)器(qi)(qi)就可(ke)以終(zhong)止充(chong)(chong)電(dian)了,但這種方式忽(hu)略了充(chong)(chong)電(dian)峰頂值(zhi)關(guan)斷(duan)操作.如(ru)在浮充(chong)(chong)電(dian)壓階段(duan),充(chong)(chong)電(dian)器(qi)(qi)會(hui)開(kai)始 定(ding)時器(qi)(qi)的操作,在一(yi)段(duan)設定(ding)緩沖期后(hou),自動終(zhong)止充(chong)(chong)電(dian).另一(yi)方式,也可(ke)監測充(chong)(chong)電(dian)電(dian)流(liu),在一(yi)個較低電(dian)流(liu)水平關(guan)斷(duan)[典型(xing)地用0.05的限(xian)定(ding)值(zhi), 一(yi)些制造商建議使用相對較高(gao)的100mA電(dian)流(liu)最小(xiao)值(zhi)].充(chong)(chong)電(dian)峰值(zhi)關(guan)斷(duan)環路往往也依(yi)靠這種技術.

最(zui)近幾年,在鋰離(li)子(zi)電(dian)池和其充電(dian)器,以及(ji)對這種(zhong)新型電(dian)池的(de)了解方(fang)面,都(dou)取得了相當的(de)進展.最(zui)早期(qi)的(de)鋰離(li)子(zi)電(dian)池在用(yong)戶的(de)使(shi)用(yong)方(fang) 面都(dou)有一些安(an)全層面的(de)缺(que)點,而這些問題已不(bu)會(hui)出現在當今(jin)設計成功的(de)系統(tong)上了.制造商們的(de)建(jian)議既不(bu)會(hui)一成不(bu)變(bian),也不(bu)會(hui)完(wan)全一致, 而鋰離(li)子(zi)電(dian)池技(ji)術會(hui)繼(ji)續(xu)向前發展.

鋰聚(ju)合物(wu)電(dian)池(chi)(chi)的充電(dian)要求和鋰離(li)子(zi)電(dian)池(chi)(chi)的要求是一樣的，可以按同類對待。

最新出現的磷酸鐵(tie)鋰電(dian)(dian)(dian)池的電(dian)(dian)(dian)壓(ya)比鋰離(li)子電(dian)(dian)(dian)池的額(e)度(du)電(dian)(dian)(dian)壓(ya)要低0.4V左右，充電(dian)(dian)(dian)的恒壓(ya)電(dian)(dian)(dian)壓(ya)設(she)定值為3.7V/節為宜。充電(dian)(dian)(dian)的方式(shi)與 鋰離(li)子電(dian)(dian)(dian)池基本相同（注意只是(shi)電(dian)(dian)(dian)壓(ya)要低一些(xie)！）

 

鉛酸電池.

鉛酸[PbSO4]蓄(xu)電(dian)(dian)(dian)(dian)池(chi)既可以用(yong)限(xian)(xian)流(liu)充(chong)電(dian)(dian)(dian)(dian),也可以用(yong)較通用(yong)簡單的(de)限(xian)(xian)壓(ya)充(chong)電(dian)(dian)(dian)(dian).限(xian)(xian)壓(ya)充(chong)電(dian)(dian)(dian)(dian)與前者(zhe)具(ju)有類似的(de)作用(yong)功能,而高精確性并非是(shi) 其關鍵.這(zhe)需要設置一個高于(yu)電(dian)(dian)(dian)(dian)池(chi)浮充(chong)電(dian)(dian)(dian)(dian)壓(ya)的(de)限(xian)(xian)流(liu)電(dian)(dian)(dian)(dian)壓(ya)源[大約2.45V左右].

經(jing)過(guo)預設狀態操作(zuo),充(chong)(chong)電(dian)器確(que)認開(kai)始快(kuai)充(chong)(chong),一直延續(xu)到(dao)最小充(chong)(chong)電(dian)電(dian)流(liu)[這個過(guo)程(cheng)類似鋰離子(zi)電(dian)池(chi)充(chong)(chong)電(dian)器],然(ran)后快(kuai)充(chong)(chong)終止.這時(shi)充(chong)(chong)電(dian)器 需要一段Vf浮充(chong)(chong)電(dian)壓進行維護(hu)[通常(chang)用(yong)(yong)2.25V左右(you)電(dian)壓].鉛酸[PbSO4]蓄電(dian)池(chi)允許在非(fei)確(que)定階段用(yong)(yong)此浮充(chong)(chong)電(dian)壓進行維護(hu)[見圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高(gao)溫(wen)環(huan)境下,對鉛(qian)酸[PbSO4]蓄電(dian)池進行(xing)快(kuai)充的電(dian)流(liu)要根據(ju)每(mei)攝氏度(du)0.3百分比的標準溫(wen)度(du)系數進行(xing)調低.快(kuai)充時設定最大電(dian)池溫(wen)度(du) 建(jian)議(yi)在50’C左(zuo)右,但(dan)浮充一(yi)般可以超(chao)過這(zhe)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]

除鋰離(li)(li)子電(dian)(dian)(dian)池(chi)外(wai),其它蓄電(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)器經(jing)常設置有一個(ge)可(ke)(ke)供選擇(ze)的涓(juan)流充電(dian)(dian)(dian)階(jie)段.這個(ge)階(jie)段的設置可(ke)(ke)以(yi)用來補(bu)償電(dian)(dian)(dian)池(chi)充滿(man)后本體的自放(fang)電(dian)(dian)(dian) 現象(xiang).鉛酸(suan)[PbSO4]電(dian)(dian)(dian)池(chi)自放(fang)電(dian)(dian)(dian)率最(zui)大[每天(tian)呈數個(ge)百分點],而(er)鋰離(li)(li)子電(dian)(dian)(dian)池(chi)最(zui)低.鋰離(li)(li)子電(dian)(dian)(dian)池(chi)的自放(fang)電(dian)(dian)(dian)率有時低到(dao)已無需涓(juan)充來維護(hu)(hu).然而(er), 鎳鎘[NiCds]蓄電(dian)(dian)(dian)池(chi)卻經(jing)常,不定地需要C/16的涓(juan)充電(dian)(dian)(dian)流以(yi)進行維護(hu)(hu).對鎳氫[NiMH]蓄電(dian)(dian)(dian)池(chi)而(er)言,安全的持續放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流經(jing)常在(zai)C/50左右,而(er)涓(juan) 流充電(dian)(dian)(dian)一般不被(bei)建(jian)議(yi).

續放電電流經(jing)常在C/50左右(you),而涓 流充電一(yi)般不被建(jian)議.