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(chong)(chong)(chong)電方法(fa)在(zai)充(chong)(chong)(chong)電初期電池內阻極低致(zhi)使(shi)充(chong)(chong)(chong)電電流過大，而隨時(shi)間(jian)并不按指數(shu)規(gui)律(lv)下降(jiang)常偏離(li)制定曲線(xian)

 

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(ren)意時刻總(zong) 存在一個最佳(jia)的充(chong)電電流(liu)和(he)充(chong)電模式的，問題是我們如何(he)才(cai)能逼近這個最佳(jia)值。 

綜合起來，判斷規則有如(ru)下幾種：

●定時控制；

●電壓控制(含最高電壓：電壓負增量(liang)(liang)：電壓零(ling)增量(liang)(liang)等)；

●溫(wen)度(du)控(kong)制(包括最高溫(wen)度(du)，最高溫(wen)升(sheng)：溫(wen)度(du)變化率等(deng))；

●電流控制等。

較好(hao)的辦(ban)法是(shi)采(cai)用綜合判(pan)斷(duan)(duan)方法，對每個指標進行跟(gen)蹤(zong)，并按(an)模糊數學原理(li)分別記分，按(an)照置(zhi)信度(du)做出最佳(jia)判(pan)斷(duan)(duan)。 電(dian)(dian)池(chi)快速(su)充電(dian)(dian)分為幾個階(jie)段(duan),見(jian)本文所述及通用充電(dian)(dian)器運(yun)行簡圖.[圖1]

　

 

圖1.通用電池充電器充電參數圖表.

 

起始階段

起始(shi)階(jie)段在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過程(cheng)中雖不屬于真正起作用(yong)的(de)那幾(ji)個(ge)階(jie)段,但(dan)在(zai)整(zheng)個(ge)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過程(cheng)中,起始(shi)階(jie)段仍是(shi)一個(ge)非常重要(yao)(yao)的(de)滿足條件(jian). 充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)啟動(dong)以(yi)后(hou)開(kai)始(shi)自測(ce),如(ru)電(dian)(dian)(dian)源出(chu)現(xian)故障或反(fan)復起動(dong),充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過程(cheng)就會(hui)(hui)(hui)被打斷.如(ru)果(guo)缺(que)乏相應智能(neng)或時(shi)(shi)間(jian)關斷裝置以(yi)及電(dian)(dian)(dian)池(chi)密 封性能(neng)不能(neng)得到改善,那么此種(zhong)現(xian)象(xiang)往(wang)往(wang)會(hui)(hui)(hui)被忽視(shi).幾(ji)乎所有的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)在(zai)電(dian)(dian)(dian)源出(chu)現(xian)故障以(yi)后(hou)都可以(yi)完全重新啟動(dong),但(dan)如(ru)過充(chong)(chong)(chong)(chong)不 被允許,充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)要(yao)(yao)能(neng)夠進行特別(bie)的(de)自測(ce)程(cheng)序以(yi)判斷電(dian)(dian)(dian)池(chi)是(shi)否(fou)早已充(chong)(chong)(chong)(chong)滿.電(dian)(dian)(dian)池(chi)狀(zhuang)態要(yao)(yao)顯現(xian)在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)指(zhi)示燈或類(lei)似的(de)顯示裝置上. （不好的(de)案(an)例：例如(ru)只靠(kao)定(ding)時(shi)(shi)的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi),用(yong)四(si)個(ge)小(xiao)時(shi)(shi)間(jian)隔(ge)的(de)固(gu)定(ding)時(shi)(shi)間(jian)給電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian).如(ru)果(guo)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)三小(xiao)時(shi)(shi)59分鐘,電(dian)(dian)(dian)源出(chu)現(xian)故障斷電(dian)(dian)(dian), 當故障清除重新送電(dian)(dian)(dian)以(yi)后(hou),充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)又(you)會(hui)(hui)(hui)開(kai)始(shi)重新一輪的(de)四(si)小(xiao)時(shi)(shi)固(gu)定(ding)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian),從而造成電(dian)(dian)(dian)池(chi)過充(chong)(chong)(chong)(chong)四(si)個(ge)小(xiao)時(shi)(shi).這種(zhong)結果(guo)往(wang)往(wang)會(hui)(hui)(hui)對(dui)電(dian)(dian)(dian)池(chi) 造成損壞(huai)。因(yin)此原因(yin),定(ding)時(shi)(shi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)很少被采用(yong)。）

充電時可充電池應備條件

當電(dian)(dian)(dian)(dian)池(chi)連(lian)接(jie)上充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)以后(hou),此充(chong)(chong)電(dian)(dian)(dian)(dian)階段之充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)要能(neng)夠有所感應(ying)顯(xian)示以及彼電(dian)(dian)(dian)(dian)池(chi)是否(fou)可以進行充(chong)(chong)電(dian)(dian)(dian)(dian).一(yi)般當充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)電(dian)(dian)(dian)(dian)源關(guan)斷 的情況下,此電(dian)(dian)(dian)(dian)池(chi)感應(ying)裝(zhuang)置(zhi)(zhi)通常(chang)根(gen)據充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)接(jie)頭的端口(kou)電(dian)(dian)(dian)(dian)壓(ya)來進行判斷,但當電(dian)(dian)(dian)(dian)池(chi)已經反復過度(du)使用或端口(kou)電(dian)(dian)(dian)(dian)壓(ya)極(ji)低的情況下, 這(zhe)種感應(ying)裝(zhuang)置(zhi)(zhi)往往會(hui)產(chan)生問題(ti).作為一(yi)種替代方法(fa),充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)經常(chang)根(gen)據溫度(du)或電(dian)(dian)(dian)(dian)壓(ya)瞬時跳變來達到上述目的.這(zhe)種硬件設置(zhi)(zhi)同(tong)樣適 用于電(dian)(dian)(dian)(dian)池(chi)組.

一(yi)旦(dan)充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)感(gan)應連接(jie)到了(le)可(ke)(ke)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池(chi)(chi),它還必須判(pan)斷出電(dian)(dian)(dian)池(chi)(chi)是否具備良好可(ke)(ke)充(chong)(chong)(chong)條件(jian).在這(zhe)個次級階段[限定(ding)(ding)條件(jian)],電(dian)(dian)(dian)池(chi)(chi)要(yao)能夠(gou) 被(bei)檢測(ce)(ce)出其基本功能狀態;開路(lu),短路(lu),高(gao)溫或是低溫.以(yi)此來檢測(ce)(ce)電(dian)(dian)(dian)池(chi)(chi)是否具備可(ke)(ke)充(chong)(chong)(chong)性,一(yi)些鉛酸充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)類型(xing)特(te)別(bie)需要(yao)一(yi)個可(ke)(ke)通過(guo) LED燈來顯(xian)示出其充(chong)(chong)(chong)電(dian)(dian)(dian)的主(zhu)充(chong)(chong)(chong)電(dian)(dian)(dian)流[大約(yue)以(yi)五分之(zhi)一(yi)的快充(chong)(chong)(chong)額定(ding)(ding)電(dian)(dian)(dian)流],并允(yun)許電(dian)(dian)(dian)池(chi)(chi)在一(yi)固定(ding)(ding)充(chong)(chong)(chong)電(dian)(dian)(dian)時間段內達到其特(te)定(ding)(ding)的電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓. 這(zhe)種技(ji)術對已經(jing)反(fan)復過(guo)度(du)使(shi)用的鉛酸[PbSO4]蓄電(dian)(dian)(dian)池(chi)(chi),應避免出現(xian)反(fan)接(jie)的問(wen)題.

對外圍(wei)設(she)(she)備(bei)和電(dian)(dian)(dian)(dian)池(chi)溫度的(de)檢(jian)測(ce)也是本階段必(bi)要(yao)條件之一.當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)檢(jian)測(ce)到電(dian)(dian)(dian)(dian)池(chi)的(de)溫度過高或過低,一般會等(deng)待一段預先設(she)(she)定(ding)的(de) 時間以使其恢復正(zheng)常.如在設(she)(she)定(ding)時間內并未恢復正(zheng)常,充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)會自(zi)動(dong)改變充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流,這(zhe)個動(dong)作相應就(jiu)調整(zheng)了(le)電(dian)(dian)(dian)(dian)池(chi)溫度,所以充(chong)(chong)電(dian)(dian)(dian)(dian)效率 會大大增加.最后,充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)需(xu)要(yao)檢(jian)測(ce)一下與電(dian)(dian)(dian)(dian)池(chi)的(de)連(lian)接狀態(tai)是開(kai)路抑或短路.通常開(kai)路狀態(tai)容易檢(jian)測(ce),而(er)一旦(dan)出(chu)現短路顯示,就(jiu)需(xu)要(yao)進 一步確認,以避免造成事故的(de)發(fa)生.如果所有檢(jian)測(ce)都獲(huo)得(de)通過,就(jiu)可以給電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)了(le).這(zhe)種設(she)(she)置相當(dang)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)器[如早期出現(xian)的(de)(de)(de)(de)(de)(de)鎳鎘(ge)電(dian)(dian)池]都設計有一(yi)個充(chong)電(dian)(dian)前期預(yu)測(ce)階(jie)段,用以(yi)判(pan)斷在重新充(chong)電(dian)(dian)前，待(dai)測(ce)電(dian)(dian)池是(shi)否已‘完(wan)(wan)全(quan)’放(fang)電(dian)(dian). 所謂(wei)‘完(wan)(wan)全(quan)’放(fang)電(dian)(dian)系(xi)指每節電(dian)(dian)池的(de)(de)(de)(de)(de)(de)端口電(dian)(dian)壓放(fang)電(dian)(dian)到1V的(de)(de)(de)(de)(de)(de)水平,以(yi)去除電(dian)(dian)解(jie)(jie)液中的(de)(de)(de)(de)(de)(de)枝狀(zhuang)結(jie)構(gou),這(zhe)也(ye)是(shi)人(ren)們(men)為什(shen)么經常(chang)(chang)錯誤地理(li)解(jie)(jie)‘記憶 效應’的(de)(de)(de)(de)(de)(de)原因[通常(chang)(chang)電(dian)(dian)池一(yi)次可(ke)充(chong)電(dian)(dian)容量(liang)是(shi)上(shang)次放(fang)電(dian)(dian)容量(liang)的(de)(de)(de)(de)(de)(de)104—110百分比].這(zhe)種所謂(wei)的(de)(de)(de)(de)(de)(de)‘記憶效應’特指電(dian)(dian)池內部電(dian)(dian)解(jie)(jie)液枝狀(zhuang)結(jie) 構(gou)狀(zhuang)態的(de)(de)(de)(de)(de)(de)自我恢(hui)復能力,如受到破(po)壞,將減少電(dian)(dian)池的(de)(de)(de)(de)(de)(de)使用壽命.所以(yi)按正常(chang)(chang)時間周期進行的(de)(de)(de)(de)(de)(de)充(chong)放(fang)電(dian)(dian),往往會解(jie)(jie)決這(zhe)個問(wen)題(ti).

在每次(ci)充電(dian)(dian)前(qian),此預測(ce)(ce)階段都會(hui)(hui)被(bei)自動(dong)完(wan)成(cheng),或(huo)在電(dian)(dian)池充電(dian)(dian)剩余過(guo)半(ban)顯示[通過(guo)連接測(ce)(ce)試或(huo)其它操作]之后.預測(ce)(ce)階段一般從一到十(shi)小 時不(bu)等(deng).在一小時之內放空電(dian)(dian)池通常(chang)不(bu)予考慮.而通過(guo)連接電(dian)(dian)阻縮短預測(ce)(ce)階段時間,會(hui)(hui)產生散熱(re)困難的(de)(de)問題.而大于(yu)十(shi)小時的(de)(de)階段設計 也往往不(bu)被(bei)采(cai)用,除(chu)非(fei)可以用手動(dong)方式(shi)開(kai)始(shi)探測(ce)(ce)減少(shao)的(de)(de)電(dian)(dian)池容量.因(yin)此,由于(yu)對鎳(nie)鎘電(dian)(dian)池’記憶效應(ying)(ying)’的(de)(de)不(bu)知和種種誤解(jie),設計人員應(ying)(ying) 避免(mian)在充電(dian)(dian)器上設置相(xiang)關按鈕來(lai)與(yu)此’效應(ying)(ying)’進行對抗.

快充階段及充電終止

快充和終止充電(dian)方式使用要(yao)根據(ju)蓄電(dian)池及其它設計因素考慮.以(yi)下探討(tao)涉及到當今通用蓄電(dian)池快充技術的(de)全面(mian)使用.如需詳(xiang)細建 議資料,可(ke)與電(dian)池制造商應用部(bu)門(men)聯系查詢.

鎳鎘,鎳氫蓄電池

鎳鎘和鎳氫蓄電(dian)(dian)(dian)(dian)池(chi)的(de)(de)快充(chong)程序非常(chang)類似,主要(yao)區別(bie)在(zai)于充(chong)電(dian)(dian)(dian)(dian)的(de)(de)終止階段.在(zai)每一(yi)個(ge)樣例中(zhong),當(dang)充(chong)電(dian)(dian)(dian)(dian)器監測電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓及其它數據,以(yi)(yi)(yi) 判斷(duan)何時終止充(chong)電(dian)(dian)(dian)(dian)時,都需要(yao)一(yi)個(ge)恒定電(dian)(dian)(dian)(dian)流.超過2C的(de)(de)充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流是可(ke)以(yi)(yi)(yi)做到的(de)(de),但一(yi)般最常(chang)用(yong)C/2左(zuo)右的(de)(de)電(dian)(dian)(dian)(dian)流.因充(chong)電(dian)(dian)(dian)(dian)效率無論怎樣都 要(yao)小于100%, 所以(yi)(yi)(yi)用(yong)C/2電(dian)(dian)(dian)(dian)流稍多于兩(liang)個(ge)小時的(de)(de)全充(chong)是可(ke)以(yi)(yi)(yi)被接(jie)受(shou)的(de)(de).

在恒(heng)流充電(dian)(dian)階段(duan),電(dian)(dian)池端(duan)口電(dian)(dian)壓緩(huan)慢上升,最終到(dao)達(da)頂點(dian)(dian)[即坡(po)度(du)為零的電(dian)(dian)壓最高(gao)點(dian)(dian)].鎳(nie)氫電(dian)(dian)池應(ying)在此點(dian)(dian)[0DV點(dian)(dian)]終止(zhi)充電(dian)(dian).而(er)鎳(nie)鎘(ge) 電(dian)(dian)池則應(ying)在此點(dian)(dian)之后某(mou)點(dian)(dian)[系電(dian)(dian)池端(duan)口電(dian)(dian)壓首次(ci)出現微小降低點(dian)(dian)即-DV點(dian)(dian)]結束,請參(can)閱圖(tu)2,可允許有少(shao)部(bu)分(fen)過充.快充如超過這兩個設 定(ding)關斷點(dian)(dian)[最高(gao)電(dian)(dian)壓點(dian)(dian)和略小的-DV點(dian)(dian)],都會對電(dian)(dian)池造(zao)成損壞.這是因為快充電(dian)(dian)流遠大于正(zheng)常慢充狀態所致.

圖2.對鎳鎘電池用C/2電流進行充電的參數特性

以大于C/2電(dian)(dian)(dian)流充(chong)(chong)電(dian)(dian)(dian)[充(chong)(chong)電(dian)(dian)(dian)時(shi)間不會超(chao)過(guo)兩個(ge)小時(shi)],充(chong)(chong)電(dian)(dian)(dian)器仍要(yao)監(jian)測電(dian)(dian)(dian)池(chi)溫度(du)(du)和電(dian)(dian)(dian)壓(ya).因為當(dang)電(dian)(dian)(dian)池(chi)充(chong)(chong)滿時(shi),電(dian)(dian)(dian)池(chi)溫度(du)(du)將上升(sheng)很快,所(suo)以 溫度(du)(du)監(jian)測元(yuan)件要(yao)啟動另(ling)一關(guan)(guan)(guan)斷(duan)(duan)(duan)裝(zhuang)置.在這正向(xiang)上升(sheng)溫度(du)(du)曲線上的(de)關(guan)(guan)(guan)斷(duan)(duan)(duan)點被稱為T關(guan)(guan)(guan)斷(duan)(duan)(duan)點.除溫度(du)(du)關(guan)(guan)(guan)斷(duan)(duan)(duan)外,其它監(jian)測數據,包括已(yi)充(chong)(chong)時(shi)間,最(zui) 大限定(ding)(ding)電(dian)(dian)(dian)池(chi)保護電(dian)(dian)(dian)壓(ya),都可參(can)預(yu)充(chong)(chong)電(dian)(dian)(dian)器關(guan)(guan)(guan)斷(duan)(duan)(duan).所(suo)以設計(ji)成(cheng)功(gong)的(de)充(chong)(chong)電(dian)(dian)(dian)器自動關(guan)(guan)(guan)斷(duan)(duan)(duan)應依(yi)據這幾種(zhong)監(jian)測因素[溫度(du)(du)關(guan)(guan)(guan)斷(duan)(duan)(duan),充(chong)(chong)電(dian)(dian)(dian)時(shi)間關(guan)(guan)(guan)斷(duan)(duan)(duan),電(dian)(dian)(dian)池(chi)最(zui)大 限定(ding)(ding)電(dian)(dian)(dian)壓(ya)關(guan)(guan)(guan)斷(duan)(duan)(duan)等]的(de)組合.

備注;當電(dian)(dian)池(chi)首次充(chong)電(dian)(dian),會產生模仿(fang)關斷狀(zhuang)態的(de)(de)特定效應(ying),因此在(zai)激活(huo)關斷模式監測曲(qu)線前(qian),充(chong)電(dian)(dian)器會引入一個 一到(dao)(dao)五分鐘的(de)(de)緩(huan)沖期.另外,充(chong)電(dian)(dian)關斷狀(zhuang)態在(zai)低于C\8電(dian)(dian)流(liu)充(chong)電(dian)(dian)時(shi)很難監測到(dao)(dao)數(shu)據,這是因為與其他(ta)系統(tong)數(shu)據比較(jiao), 電(dian)(dian)壓和(he)溫度曲(qu)線[V/t和(he)T/t]斜(xie)率(lv)很小所致.為快(kuai)速充(chong)電(dian)(dian)的(de)(de)安全起見(jian),這些系統(tong)中的(de)(de)硬軟件配置總是會造成充(chong)電(dian)(dian)器提(ti) 前(qian)關斷的(de)(de)誤操作動作.

 

鋰離子電池

鋰離子蓄(xu)電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)曲線(xian)和鎳離子蓄(xu)電(dian)(dian)(dian)(dian)(dian)池相比很(hen)不一樣.充(chong)電(dian)(dian)(dian)(dian)(dian)關(guan)斷要(yao)確(que)定到最(zui)大安全值之后才會動作.鋰電(dian)(dian)(dian)(dian)(dian)充(chong)電(dian)(dian)(dian)(dian)(dian)器要(yao)將充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓控制(zhi) 在小于0.75%的精確(que)范圍內(nei),并且其最(zui)大充(chong)電(dian)(dian)(dian)(dian)(dian)效率用充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)限定控制(zhi),非常類似(si)臺式桌面型直流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源. 當快充(chong)開(kai)始(shi)時,電(dian)(dian)(dian)(dian)(dian)池端口電(dian)(dian)(dian)(dian)(dian)壓相 對較低,充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)就等同于其限定電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)值.

在充(chong)電(dian)(dian)過程中,電(dian)(dian)池電(dian)(dian)壓(ya)(ya)緩慢上升(sheng).最后,充(chong)電(dian)(dian)電(dian)(dian)流到(dao)(dao)達設定峰值,充(chong)電(dian)(dian)電(dian)(dian)壓(ya)(ya)上升(sheng)到(dao)(dao)每節 4.2V的浮(fu)充(chong)電(dian)(dian)壓(ya)(ya)水平[見圖(tu)4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)到浮充(chong)電(dian)(dian)(dian)(dian)壓(ya)水平,充(chong)電(dian)(dian)(dian)(dian)器(qi)就(jiu)可(ke)以終止充(chong)電(dian)(dian)(dian)(dian)了,但這種方式忽略(lve)了充(chong)電(dian)(dian)(dian)(dian)峰頂值關斷操作(zuo)(zuo).如(ru)在(zai)浮充(chong)電(dian)(dian)(dian)(dian)壓(ya)階段(duan),充(chong)電(dian)(dian)(dian)(dian)器(qi)會開(kai)始(shi) 定時(shi)器(qi)的操作(zuo)(zuo),在(zai)一段(duan)設定緩(huan)沖期后,自動終止充(chong)電(dian)(dian)(dian)(dian).另(ling)一方式,也可(ke)監測充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流,在(zai)一個較低電(dian)(dian)(dian)(dian)流水平關斷[典型(xing)地用0.05的限定值, 一些制(zhi)造(zao)商(shang)建議使用相對較高(gao)的100mA電(dian)(dian)(dian)(dian)流最(zui)小值].充(chong)電(dian)(dian)(dian)(dian)峰值關斷環路往(wang)往(wang)也依靠這種技術.

最近幾年,在鋰(li)(li)離(li)子電(dian)(dian)池(chi)和(he)其充電(dian)(dian)器,以(yi)及對這種新型(xing)電(dian)(dian)池(chi)的了解方面(mian),都取得了相當(dang)的進(jin)展(zhan).最早期的鋰(li)(li)離(li)子電(dian)(dian)池(chi)在用戶的使用方 面(mian)都有一(yi)(yi)些(xie)安全(quan)層面(mian)的缺點,而這些(xie)問題(ti)已不(bu)會(hui)出現在當(dang)今設計成(cheng)功的系統上了.制造商們(men)的建議既不(bu)會(hui)一(yi)(yi)成(cheng)不(bu)變,也不(bu)會(hui)完全(quan)一(yi)(yi)致, 而鋰(li)(li)離(li)子電(dian)(dian)池(chi)技術會(hui)繼續向(xiang)前發展(zhan).

鋰聚(ju)合(he)物電池(chi)的(de)充電要求和鋰離子(zi)電池(chi)的(de)要求是一樣的(de)，可以(yi)按同(tong)類對(dui)待(dai)。

最新(xin)出現的磷(lin)酸鐵(tie)鋰電(dian)(dian)(dian)(dian)池的電(dian)(dian)(dian)(dian)壓(ya)比鋰離子電(dian)(dian)(dian)(dian)池的額度電(dian)(dian)(dian)(dian)壓(ya)要(yao)低0.4V左(zuo)右(you)，充(chong)電(dian)(dian)(dian)(dian)的恒壓(ya)電(dian)(dian)(dian)(dian)壓(ya)設定值為(wei)(wei)3.7V/節為(wei)(wei)宜。充(chong)電(dian)(dian)(dian)(dian)的方(fang)式與 鋰離子電(dian)(dian)(dian)(dian)池基本相同（注(zhu)意(yi)只是電(dian)(dian)(dian)(dian)壓(ya)要(yao)低一些(xie)！）

 

鉛酸電池.

鉛酸[PbSO4]蓄(xu)電(dian)(dian)(dian)池既可(ke)以用(yong)(yong)限(xian)(xian)(xian)流充(chong)(chong)電(dian)(dian)(dian),也可(ke)以用(yong)(yong)較(jiao)通用(yong)(yong)簡單的限(xian)(xian)(xian)壓(ya)充(chong)(chong)電(dian)(dian)(dian).限(xian)(xian)(xian)壓(ya)充(chong)(chong)電(dian)(dian)(dian)與前者具(ju)有類似的作用(yong)(yong)功能(neng),而高精(jing)確(que)性(xing)并非是 其(qi)關鍵.這需(xu)要設置一個高于電(dian)(dian)(dian)池浮充(chong)(chong)電(dian)(dian)(dian)壓(ya)的限(xian)(xian)(xian)流電(dian)(dian)(dian)壓(ya)源[大約2.45V左右(you)].

經過預設狀態操作,充(chong)電(dian)器(qi)確認開始快充(chong),一(yi)直延續(xu)到(dao)最小充(chong)電(dian)電(dian)流[這(zhe)個(ge)過程類似鋰離子電(dian)池充(chong)電(dian)器(qi)],然后(hou)快充(chong)終止.這(zhe)時充(chong)電(dian)器(qi) 需要一(yi)段Vf浮充(chong)電(dian)壓進行維(wei)護[通常(chang)用(yong)2.25V左右電(dian)壓].鉛(qian)酸[PbSO4]蓄(xu)電(dian)池允許在非(fei)確定(ding)階段用(yong)此浮充(chong)電(dian)壓進行維(wei)護[見圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高溫環境(jing)下,對鉛(qian)酸[PbSO4]蓄電池(chi)進行快(kuai)充(chong)的電流要根據每攝(she)氏度0.3百分(fen)比的標準(zhun)溫度系數進行調低.快(kuai)充(chong)時(shi)設定最大電池(chi)溫度 建(jian)議在50’C左右,但(dan)浮充(chong)一般可以(yi)超過這個溫度.

 

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)子電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)外,其它蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)器經常設置(zhi)有(you)一(yi)個(ge)可(ke)供選擇的(de)(de)涓(juan)流充(chong)電(dian)(dian)(dian)(dian)(dian)階(jie)段.這(zhe)個(ge)階(jie)段的(de)(de)設置(zhi)可(ke)以(yi)用來補償電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)滿后本體的(de)(de)自放電(dian)(dian)(dian)(dian)(dian) 現象(xiang).鉛酸(suan)[PbSO4]電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)自放電(dian)(dian)(dian)(dian)(dian)率最大[每天呈數個(ge)百分(fen)點],而鋰(li)離(li)子電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)最低(di).鋰(li)離(li)子電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)自放電(dian)(dian)(dian)(dian)(dian)率有(you)時低(di)到已無需(xu)涓(juan)充(chong)來維護(hu).然(ran)而, 鎳(nie)鎘[NiCds]蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)卻經常,不定(ding)地需(xu)要C/16的(de)(de)涓(juan)充(chong)電(dian)(dian)(dian)(dian)(dian)流以(yi)進行維護(hu).對鎳(nie)氫[NiMH]蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)而言,安(an)全的(de)(de)持續放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流經常在C/50左(zuo)右,而涓(juan) 流充(chong)電(dian)(dian)(dian)(dian)(dian)一(yi)般不被建議.

續(xu)放(fang)電電流(liu)經常(chang)在(zai)C/50左右,而(er)涓 流(liu)充電一般不被(bei)建議.