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(heng)壓 充(chong)(chong)(chong)電(dian)(dian)(dian)方法在充(chong)(chong)(chong)電(dian)(dian)(dian)初(chu)期電(dian)(dian)(dian)池內阻極低致使充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流過大，而隨時間并不按指(zhi)數(shu)規律下(xia)降常偏離制定曲線

 

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刻總 存在一個(ge)最(zui)佳的充(chong)電電流和充(chong)電模式的，問題是我們如何才能逼(bi)近這個(ge)最(zui)佳值。 

綜(zong)合起來，判斷規(gui)則(ze)有如下幾(ji)種(zhong)：

●定時控制；

●電(dian)(dian)壓(ya)控制(含最高(gao)電(dian)(dian)壓(ya)：電(dian)(dian)壓(ya)負(fu)增量：電(dian)(dian)壓(ya)零增量等)；

●溫度(du)控(kong)制(zhi)(包(bao)括最(zui)高溫度(du)，最(zui)高溫升：溫度(du)變(bian)化率等)；

●電流控制等。

較好的辦(ban)法(fa)是(shi)采用(yong)綜合(he)判斷方(fang)法(fa)，對每個(ge)(ge)指標進行跟蹤，并按(an)模糊數(shu)學原理(li)分別記分，按(an)照置信度(du)做出最佳判斷。 電池快速充(chong)電分為幾個(ge)(ge)階段,見(jian)本文所述及通用(yong)充(chong)電器運行簡圖.[圖1]

　

 

圖1.通用(yong)電(dian)(dian)池充電(dian)(dian)器充電(dian)(dian)參數圖表(biao).

 

起始階段

起(qi)(qi)始階段(duan)在(zai)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)中雖不屬于真(zhen)正起(qi)(qi)作用的(de)(de)(de)那幾個(ge)(ge)(ge)階段(duan),但在(zai)整個(ge)(ge)(ge)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)中,起(qi)(qi)始階段(duan)仍是一個(ge)(ge)(ge)非常重(zhong)(zhong)要的(de)(de)(de)滿(man)足條件. 充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)啟動以(yi)后開始自測,如(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源出(chu)現(xian)(xian)故障(zhang)或(huo)反(fan)復起(qi)(qi)動,充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)就(jiu)會(hui)被(bei)(bei)打斷(duan).如(ru)果(guo)缺(que)乏相應智能(neng)或(huo)時(shi)間關斷(duan)裝置以(yi)及電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)密 封性能(neng)不能(neng)得到改善(shan),那么此(ci)(ci)種現(xian)(xian)象往(wang)往(wang)會(hui)被(bei)(bei)忽(hu)視(shi).幾乎所有的(de)(de)(de)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源出(chu)現(xian)(xian)故障(zhang)以(yi)后都可以(yi)完全(quan)重(zhong)(zhong)新啟動,但如(ru)過充(chong)(chong)(chong)(chong)(chong)(chong)不 被(bei)(bei)允許,充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)要能(neng)夠(gou)進行(xing)特別(bie)的(de)(de)(de)自測程(cheng)序以(yi)判斷(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)是否(fou)早(zao)已(yi)充(chong)(chong)(chong)(chong)(chong)(chong)滿(man).電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)狀態要顯(xian)現(xian)(xian)在(zai)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)指示燈或(huo)類(lei)似(si)的(de)(de)(de)顯(xian)示裝置上. （不好的(de)(de)(de)案例：例如(ru)只靠定(ding)時(shi)的(de)(de)(de)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi),用四(si)個(ge)(ge)(ge)小(xiao)(xiao)時(shi)間隔(ge)的(de)(de)(de)固定(ding)時(shi)間給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian).如(ru)果(guo)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)三小(xiao)(xiao)時(shi)59分鐘(zhong),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源出(chu)現(xian)(xian)故障(zhang)斷(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian), 當故障(zhang)清除重(zhong)(zhong)新送電(dian)(dian)(dian)(dian)(dian)(dian)(dian)以(yi)后,充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)又會(hui)開始重(zhong)(zhong)新一輪的(de)(de)(de)四(si)小(xiao)(xiao)時(shi)固定(ding)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian),從而造成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)過充(chong)(chong)(chong)(chong)(chong)(chong)四(si)個(ge)(ge)(ge)小(xiao)(xiao)時(shi).這種結果(guo)往(wang)往(wang)會(hui)對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi) 造成損壞。因此(ci)(ci)原因,定(ding)時(shi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)很少被(bei)(bei)采用。）

充電時可充電池應備條件

當(dang)電池連接上充電器(qi)以(yi)后,此(ci)充電階段之充電器(qi)要能夠有所(suo)感應顯示以(yi)及彼電池是否可以(yi)進(jin)行充電.一般當(dang)充電器(qi)電源關斷 的情(qing)況(kuang)下,此(ci)電池感應裝置通(tong)常根據(ju)(ju)充電器(qi)接頭的端口電壓(ya)來(lai)進(jin)行判斷,但當(dang)電池已經(jing)反復(fu)過度(du)使用(yong)或端口電壓(ya)極低的情(qing)況(kuang)下, 這(zhe)種(zhong)感應裝置往(wang)往(wang)會產生問題.作為(wei)一種(zhong)替(ti)代方法,充電器(qi)經(jing)常根據(ju)(ju)溫(wen)度(du)或電壓(ya)瞬(shun)時跳變(bian)來(lai)達到上述目的.這(zhe)種(zhong)硬件設置同樣適 用(yong)于(yu)電池組.

一(yi)旦(dan)充(chong)電(dian)(dian)(dian)器感應連接(jie)到了可充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池,它還必須(xu)判斷出(chu)(chu)電(dian)(dian)(dian)池是否具備良好(hao)可充(chong)條(tiao)件.在(zai)這(zhe)個次級階(jie)段(duan)[限(xian)定條(tiao)件],電(dian)(dian)(dian)池要能夠 被檢(jian)測(ce)出(chu)(chu)其(qi)基本功能狀態;開路,短路,高溫(wen)或(huo)是低溫(wen).以(yi)此來(lai)檢(jian)測(ce)電(dian)(dian)(dian)池是否具備可充(chong)性,一(yi)些鉛酸充(chong)電(dian)(dian)(dian)器類(lei)型特別需要一(yi)個可通過 LED燈來(lai)顯示出(chu)(chu)其(qi)充(chong)電(dian)(dian)(dian)的(de)主(zhu)充(chong)電(dian)(dian)(dian)流[大約(yue)以(yi)五分之一(yi)的(de)快充(chong)額定電(dian)(dian)(dian)流],并允許電(dian)(dian)(dian)池在(zai)一(yi)固(gu)定充(chong)電(dian)(dian)(dian)時(shi)間段(duan)內(nei)達到其(qi)特定的(de)電(dian)(dian)(dian)池電(dian)(dian)(dian)壓. 這(zhe)種技術對已(yi)經反復過度使用(yong)的(de)鉛酸[PbSO4]蓄電(dian)(dian)(dian)池,應避免出(chu)(chu)現反接(jie)的(de)問題.

對外圍設(she)(she)備和電(dian)(dian)(dian)池溫度的(de)檢測(ce)也是本階(jie)段必要(yao)條(tiao)件之一.當(dang)充(chong)(chong)電(dian)(dian)(dian)器(qi)檢測(ce)到(dao)電(dian)(dian)(dian)池的(de)溫度過高或(huo)過低,一般會等待一段預先設(she)(she)定的(de) 時間以(yi)使其恢復正常(chang).如在設(she)(she)定時間內并(bing)未恢復正常(chang),充(chong)(chong)電(dian)(dian)(dian)器(qi)會自動(dong)改變(bian)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流,這個動(dong)作相應(ying)就調整了電(dian)(dian)(dian)池溫度,所(suo)以(yi)充(chong)(chong)電(dian)(dian)(dian)效率 會大大增(zeng)加.最后,充(chong)(chong)電(dian)(dian)(dian)器(qi)需要(yao)檢測(ce)一下與(yu)電(dian)(dian)(dian)池的(de)連接狀態是開路抑(yi)或(huo)短路.通(tong)(tong)常(chang)開路狀態容易檢測(ce),而一旦出現短路顯示,就需要(yao)進 一步確認(ren),以(yi)避(bi)免造(zao)成(cheng)事(shi)故的(de)發(fa)生.如果所(suo)有檢測(ce)都獲得通(tong)(tong)過,就可以(yi)給電(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)了.這種(zhong)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)(dian)(dian)(dian)器[如早期(qi)(qi)出(chu)現的(de)(de)鎳(nie)鎘電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)]都設(she)計有一(yi)個充(chong)電(dian)(dian)(dian)(dian)(dian)前期(qi)(qi)預測(ce)階段,用以判斷在重新充(chong)電(dian)(dian)(dian)(dian)(dian)前，待(dai)測(ce)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是否已‘完(wan)全(quan)(quan)’放(fang)電(dian)(dian)(dian)(dian)(dian). 所謂‘完(wan)全(quan)(quan)’放(fang)電(dian)(dian)(dian)(dian)(dian)系指每(mei)節電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)端口電(dian)(dian)(dian)(dian)(dian)壓放(fang)電(dian)(dian)(dian)(dian)(dian)到1V的(de)(de)水平(ping),以去除電(dian)(dian)(dian)(dian)(dian)解液中的(de)(de)枝狀(zhuang)結(jie)構(gou),這也是人(ren)們為什(shen)么經常(chang)(chang)錯誤地理解‘記(ji)憶 效應’的(de)(de)原因[通常(chang)(chang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)一(yi)次可充(chong)電(dian)(dian)(dian)(dian)(dian)容(rong)量是上次放(fang)電(dian)(dian)(dian)(dian)(dian)容(rong)量的(de)(de)104—110百分(fen)比].這種所謂的(de)(de)‘記(ji)憶效應’特指電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)內(nei)部電(dian)(dian)(dian)(dian)(dian)解液枝狀(zhuang)結(jie) 構(gou)狀(zhuang)態的(de)(de)自(zi)我恢復能(neng)力,如受(shou)到破壞(huai),將(jiang)減少電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)使用壽命(ming).所以按正常(chang)(chang)時間(jian)周(zhou)期(qi)(qi)進行的(de)(de)充(chong)放(fang)電(dian)(dian)(dian)(dian)(dian),往(wang)(wang)往(wang)(wang)會解決這個問題.

在(zai)每次充電(dian)前(qian),此預(yu)測階(jie)(jie)(jie)段(duan)都會(hui)被自動完成,或(huo)在(zai)電(dian)池充電(dian)剩余過半(ban)顯示[通過連(lian)接測試或(huo)其它操作(zuo)]之后.預(yu)測階(jie)(jie)(jie)段(duan)一般從一到十小(xiao) 時不(bu)等.在(zai)一小(xiao)時之內放(fang)空電(dian)池通常不(bu)予考慮.而(er)通過連(lian)接電(dian)阻縮短預(yu)測階(jie)(jie)(jie)段(duan)時間,會(hui)產生散熱(re)困難的(de)問題.而(er)大(da)于(yu)十小(xiao)時的(de)階(jie)(jie)(jie)段(duan)設計(ji) 也往往不(bu)被采用,除非可以用手動方式(shi)開(kai)始探測減(jian)少(shao)的(de)電(dian)池容量.因此,由于(yu)對(dui)鎳鎘電(dian)池’記憶(yi)效應’的(de)不(bu)知和(he)種(zhong)(zhong)種(zhong)(zhong)誤解,設計(ji)人(ren)員應 避免在(zai)充電(dian)器上設置(zhi)相關(guan)按鈕來與此’效應’進行(xing)對(dui)抗.

快充階段及充電終止

快(kuai)充(chong)(chong)和終止充(chong)(chong)電方(fang)式使用要根據蓄(xu)(xu)電池(chi)(chi)(chi)及其它設計因素考慮.以(yi)下探討涉(she)及到當今通用蓄(xu)(xu)電池(chi)(chi)(chi)快(kuai)充(chong)(chong)技(ji)術的全面使用.如(ru)需詳細(xi)建 議資料,可與電池(chi)(chi)(chi)制造商應用部門(men)聯系查詢.

鎳鎘,鎳氫蓄電池

鎳鎘和鎳氫蓄電(dian)(dian)(dian)池的(de)(de)(de)(de)(de)快(kuai)充(chong)程序非常(chang)類(lei)似,主要(yao)區別在(zai)于(yu)充(chong)電(dian)(dian)(dian)的(de)(de)(de)(de)(de)終止階段.在(zai)每一個(ge)樣例中,當充(chong)電(dian)(dian)(dian)器監(jian)測電(dian)(dian)(dian)池電(dian)(dian)(dian)壓及(ji)其它(ta)數(shu)據(ju),以 判斷何(he)時(shi)終止充(chong)電(dian)(dian)(dian)時(shi),都(dou)需要(yao)一個(ge)恒定電(dian)(dian)(dian)流.超(chao)過2C的(de)(de)(de)(de)(de)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流是(shi)可以做到的(de)(de)(de)(de)(de),但一般最常(chang)用C/2左右的(de)(de)(de)(de)(de)電(dian)(dian)(dian)流.因充(chong)電(dian)(dian)(dian)效(xiao)率(lv)無論怎樣都(dou) 要(yao)小于(yu)100%, 所以用C/2電(dian)(dian)(dian)流稍多(duo)于(yu)兩個(ge)小時(shi)的(de)(de)(de)(de)(de)全充(chong)是(shi)可以被接受的(de)(de)(de)(de)(de).

在恒流(liu)充電(dian)(dian)(dian)(dian)階(jie)段,電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)端口電(dian)(dian)(dian)(dian)壓(ya)緩慢(man)上升,最(zui)(zui)終到達頂點(dian)[即坡度(du)為(wei)零的(de)電(dian)(dian)(dian)(dian)壓(ya)最(zui)(zui)高(gao)點(dian)].鎳氫電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)應在此點(dian)[0DV點(dian)]終止充電(dian)(dian)(dian)(dian).而鎳鎘(ge) 電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)則應在此點(dian)之后某點(dian)[系電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)端口電(dian)(dian)(dian)(dian)壓(ya)首次出現微(wei)小降低點(dian)即-DV點(dian)]結束,請參(can)閱圖2,可(ke)允許有(you)少(shao)部分(fen)過充.快充如超過這(zhe)兩個設 定關斷點(dian)[最(zui)(zui)高(gao)電(dian)(dian)(dian)(dian)壓(ya)點(dian)和略(lve)小的(de)-DV點(dian)],都會(hui)對電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)造成損壞.這(zhe)是因為(wei)快充電(dian)(dian)(dian)(dian)流(liu)遠(yuan)大于正常慢(man)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)(dian)流充電(dian)(dian)(dian)(dian)[充電(dian)(dian)(dian)(dian)時(shi)(shi)間不會超過兩個小時(shi)(shi)],充電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)仍要監測電(dian)(dian)(dian)(dian)池(chi)(chi)溫(wen)(wen)度(du)(du)和電(dian)(dian)(dian)(dian)壓(ya).因(yin)為當(dang)電(dian)(dian)(dian)(dian)池(chi)(chi)充滿(man)時(shi)(shi),電(dian)(dian)(dian)(dian)池(chi)(chi)溫(wen)(wen)度(du)(du)將上升很(hen)快,所以 溫(wen)(wen)度(du)(du)監測元件要啟動另一關(guan)斷(duan)(duan)裝置.在這正(zheng)向上升溫(wen)(wen)度(du)(du)曲線上的(de)關(guan)斷(duan)(duan)點(dian)被(bei)稱為T關(guan)斷(duan)(duan)點(dian).除溫(wen)(wen)度(du)(du)關(guan)斷(duan)(duan)外(wai),其它監測數據,包括已充時(shi)(shi)間,最 大限定電(dian)(dian)(dian)(dian)池(chi)(chi)保護電(dian)(dian)(dian)(dian)壓(ya),都可參預充電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)關(guan)斷(duan)(duan).所以設計成(cheng)功的(de)充電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)自動關(guan)斷(duan)(duan)應依據這幾種監測因(yin)素[溫(wen)(wen)度(du)(du)關(guan)斷(duan)(duan),充電(dian)(dian)(dian)(dian)時(shi)(shi)間關(guan)斷(duan)(duan),電(dian)(dian)(dian)(dian)池(chi)(chi)最大 限定電(dian)(dian)(dian)(dian)壓(ya)關(guan)斷(duan)(duan)等]的(de)組合.

備注;當(dang)電(dian)(dian)池(chi)首次充(chong)(chong)(chong)(chong)電(dian)(dian),會(hui)(hui)產生模仿(fang)關(guan)斷(duan)狀態的特定效應,因(yin)此在激活關(guan)斷(duan)模式監測曲線前(qian)(qian),充(chong)(chong)(chong)(chong)電(dian)(dian)器會(hui)(hui)引入一個 一到五分鐘的緩沖期.另外,充(chong)(chong)(chong)(chong)電(dian)(dian)關(guan)斷(duan)狀態在低于C\8電(dian)(dian)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)時很(hen)難監測到數據(ju)(ju),這是因(yin)為與其他系(xi)統(tong)數據(ju)(ju)比(bi)較, 電(dian)(dian)壓(ya)和溫度曲線[V/t和T/t]斜率很(hen)小所致.為快速(su)充(chong)(chong)(chong)(chong)電(dian)(dian)的安全起見,這些系(xi)統(tong)中的硬(ying)軟件配(pei)置(zhi)總(zong)是會(hui)(hui)造成充(chong)(chong)(chong)(chong)電(dian)(dian)器提 前(qian)(qian)關(guan)斷(duan)的誤(wu)操作動(dong)作.

 

鋰離子電池

鋰離(li)子蓄電(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)曲(qu)線和鎳離(li)子蓄電(dian)(dian)池相比很不(bu)一(yi)樣(yang).充(chong)(chong)(chong)電(dian)(dian)關斷要確(que)定(ding)到最大安全值(zhi)之后才會動作.鋰電(dian)(dian)充(chong)(chong)(chong)電(dian)(dian)器要將充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)壓控制 在小(xiao)于0.75%的精(jing)確(que)范(fan)圍內(nei),并(bing)且其(qi)最大充(chong)(chong)(chong)電(dian)(dian)效率用充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)限定(ding)控制,非常(chang)類似臺(tai)式桌(zhuo)面(mian)型直(zhi)流(liu)電(dian)(dian)源. 當快充(chong)(chong)(chong)開始(shi)時,電(dian)(dian)池端口電(dian)(dian)壓相 對(dui)較低,充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)就等同于其(qi)限定(ding)電(dian)(dian)流(liu)值(zhi).

在充電過程中,電池電壓(ya)(ya)緩慢上升.最后,充電電流到(dao)達設定(ding)峰(feng)值,充電電壓(ya)(ya)上升到(dao)每節 4.2V的(de)浮充電壓(ya)(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)電(dian)(dian)(dian)(dian)到浮(fu)充(chong)電(dian)(dian)(dian)(dian)壓水平(ping),充(chong)電(dian)(dian)(dian)(dian)器就可以終止充(chong)電(dian)(dian)(dian)(dian)了(le),但這種(zhong)方式(shi)忽(hu)略了(le)充(chong)電(dian)(dian)(dian)(dian)峰頂值關斷操(cao)(cao)作(zuo).如(ru)在浮(fu)充(chong)電(dian)(dian)(dian)(dian)壓階(jie)段,充(chong)電(dian)(dian)(dian)(dian)器會(hui)開始(shi) 定(ding)時器的(de)操(cao)(cao)作(zuo),在一(yi)段設定(ding)緩沖期后,自動終止充(chong)電(dian)(dian)(dian)(dian).另一(yi)方式(shi),也可監測充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu),在一(yi)個較低電(dian)(dian)(dian)(dian)流(liu)水平(ping)關斷[典型地用0.05的(de)限定(ding)值, 一(yi)些制造商建議使用相對較高的(de)100mA電(dian)(dian)(dian)(dian)流(liu)最(zui)小(xiao)值].充(chong)電(dian)(dian)(dian)(dian)峰值關斷環路往往也依(yi)靠這種(zhong)技(ji)術.

最(zui)近幾年,在鋰(li)離子電(dian)池(chi)(chi)(chi)和(he)其充(chong)電(dian)器,以及對(dui)這(zhe)種新(xin)型(xing)電(dian)池(chi)(chi)(chi)的(de)(de)了(le)(le)解方面,都取(qu)得(de)了(le)(le)相當的(de)(de)進展.最(zui)早期的(de)(de)鋰(li)離子電(dian)池(chi)(chi)(chi)在用戶的(de)(de)使用方 面都有一些安(an)全層面的(de)(de)缺點,而(er)這(zhe)些問(wen)題已不(bu)(bu)會(hui)(hui)出現在當今設(she)計(ji)成功的(de)(de)系(xi)統上了(le)(le).制造(zao)商(shang)們的(de)(de)建議既不(bu)(bu)會(hui)(hui)一成不(bu)(bu)變,也不(bu)(bu)會(hui)(hui)完全一致, 而(er)鋰(li)離子電(dian)池(chi)(chi)(chi)技術會(hui)(hui)繼續向前發展.

鋰(li)聚合物電(dian)池(chi)的充電(dian)要(yao)求(qiu)和(he)鋰(li)離子(zi)電(dian)池(chi)的要(yao)求(qiu)是一樣的，可以按同類(lei)對待。

最新(xin)出現(xian)的(de)磷酸鐵鋰電(dian)(dian)池的(de)電(dian)(dian)壓(ya)比鋰離(li)(li)子電(dian)(dian)池的(de)額(e)度電(dian)(dian)壓(ya)要低(di)0.4V左(zuo)右，充電(dian)(dian)的(de)恒壓(ya)電(dian)(dian)壓(ya)設定(ding)值為3.7V/節為宜。充電(dian)(dian)的(de)方式與 鋰離(li)(li)子電(dian)(dian)池基本相同（注意只是電(dian)(dian)壓(ya)要低(di)一些！）

 

鉛酸電池.

鉛酸[PbSO4]蓄電池既(ji)可(ke)以(yi)用限流充(chong)電,也可(ke)以(yi)用較(jiao)通用簡單的限壓充(chong)電.限壓充(chong)電與前者具有類(lei)似的作用功能,而高精確性并非(fei)是 其(qi)關鍵.這需要(yao)設(she)置(zhi)一個高于電池浮充(chong)電壓的限流電壓源(yuan)[大約2.45V左(zuo)右(you)].

經過預設狀(zhuang)態操作(zuo),充電(dian)(dian)器確(que)認(ren)開(kai)始快充,一直延續到最小(xiao)充電(dian)(dian)電(dian)(dian)流[這個過程類似鋰(li)離子電(dian)(dian)池(chi)充電(dian)(dian)器],然后快充終止.這時充電(dian)(dian)器 需要一段Vf浮充電(dian)(dian)壓(ya)進(jin)行(xing)維(wei)護[通(tong)常用(yong)2.25V左右電(dian)(dian)壓(ya)].鉛酸[PbSO4]蓄電(dian)(dian)池(chi)允許在非確(que)定階(jie)段用(yong)此浮充電(dian)(dian)壓(ya)進(jin)行(xing)維(wei)護[見(jian)圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高溫環境下,對鉛酸[PbSO4]蓄電池(chi)進(jin)行(xing)快充的(de)電流要根(gen)據每攝氏度0.3百分比的(de)標準溫度系數進(jin)行(xing)調低.快充時(shi)設定最大(da)電池(chi)溫度 建議在50’C左右,但浮(fu)充一(yi)般可以超過(guo)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(chu)鋰離(li)子(zi)電(dian)(dian)池外,其它(ta)蓄(xu)電(dian)(dian)池充(chong)(chong)電(dian)(dian)器經常(chang)設(she)置有一(yi)個可供選擇的(de)涓(juan)(juan)流(liu)(liu)充(chong)(chong)電(dian)(dian)階段.這個階段的(de)設(she)置可以用來(lai)補償電(dian)(dian)池充(chong)(chong)滿后本(ben)體的(de)自放電(dian)(dian) 現象.鉛酸[PbSO4]電(dian)(dian)池自放電(dian)(dian)率最大[每天呈數個百分(fen)點],而(er)鋰離(li)子(zi)電(dian)(dian)池最低.鋰離(li)子(zi)電(dian)(dian)池的(de)自放電(dian)(dian)率有時低到已無需涓(juan)(juan)充(chong)(chong)來(lai)維護.然而(er), 鎳鎘[NiCds]蓄(xu)電(dian)(dian)池卻經常(chang),不定地需要C/16的(de)涓(juan)(juan)充(chong)(chong)電(dian)(dian)流(liu)(liu)以進(jin)行維護.對(dui)鎳氫[NiMH]蓄(xu)電(dian)(dian)池而(er)言,安全的(de)持續放電(dian)(dian)電(dian)(dian)流(liu)(liu)經常(chang)在C/50左(zuo)右(you),而(er)涓(juan)(juan) 流(liu)(liu)充(chong)(chong)電(dian)(dian)一(yi)般不被建議(yi).

續(xu)放電(dian)電(dian)流(liu)經常在C/50左右,而涓(juan) 流(liu)充電(dian)一(yi)般不被建議.