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(ya) 充(chong)電(dian)方(fang)法在(zai)充(chong)電(dian)初期電(dian)池內阻極低致(zhi)使充(chong)電(dian)電(dian)流過大(da)，而隨時間并不按指(zhi)數規律下降常偏離(li)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(de)任(ren)意時刻總 存在(zai)一個最(zui)佳的(de)充電電流和充電模式的(de)，問題是(shi)我們如何才(cai)能(neng)逼近這(zhe)個最(zui)佳值。 

綜合起來，判斷規(gui)則有如下幾種：

●定時控制；

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

●溫(wen)度控制(包括最高溫(wen)度，最高溫(wen)升：溫(wen)度變化率等)；

●電流控制等。

較好(hao)的辦法(fa)(fa)是采用(yong)綜合判(pan)斷方(fang)法(fa)(fa)，對每(mei)個指(zhi)標進行(xing)跟蹤，并按模糊數學原理分別(bie)記分，按照置信度做出最(zui)佳(jia)判(pan)斷。 電(dian)池快速充(chong)電(dian)分為幾個階段,見本文所述及通用(yong)充(chong)電(dian)器運行(xing)簡圖(tu).[圖(tu)1]

　

 

圖1.通用電(dian)池(chi)充電(dian)器充電(dian)參(can)數圖表.

 

起始階段

起(qi)(qi)始(shi)階(jie)段在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng)中雖不屬(shu)于真正起(qi)(qi)作用(yong)的(de)那幾個階(jie)段,但在(zai)整個充(chong)電(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng)中,起(qi)(qi)始(shi)階(jie)段仍(reng)是一(yi)個非(fei)常重(zhong)要的(de)滿(man)足(zu)條件. 充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)啟(qi)(qi)動以(yi)(yi)后開(kai)始(shi)自測,如電(dian)(dian)(dian)(dian)(dian)源(yuan)出(chu)現故障(zhang)或反復起(qi)(qi)動,充(chong)電(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng)就(jiu)會(hui)被(bei)打斷(duan)(duan).如果缺乏相應智能或時(shi)(shi)間關斷(duan)(duan)裝(zhuang)置以(yi)(yi)及電(dian)(dian)(dian)(dian)(dian)池(chi)密(mi) 封性能不能得到改善,那么(me)此種現象(xiang)往往會(hui)被(bei)忽視(shi).幾乎(hu)所有的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)在(zai)電(dian)(dian)(dian)(dian)(dian)源(yuan)出(chu)現故障(zhang)以(yi)(yi)后都可以(yi)(yi)完全重(zhong)新啟(qi)(qi)動,但如過(guo)充(chong)不 被(bei)允許,充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)要能夠(gou)進行特別(bie)的(de)自測程(cheng)(cheng)(cheng)序以(yi)(yi)判斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian)池(chi)是否早已充(chong)滿(man).電(dian)(dian)(dian)(dian)(dian)池(chi)狀態要顯現在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)指(zhi)示燈或類(lei)似的(de)顯示裝(zhuang)置上. （不好的(de)案例：例如只靠定時(shi)(shi)的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi),用(yong)四(si)個小時(shi)(shi)間隔的(de)固定時(shi)(shi)間給電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)(dian).如果充(chong)電(dian)(dian)(dian)(dian)(dian)三(san)小時(shi)(shi)59分鐘,電(dian)(dian)(dian)(dian)(dian)源(yuan)出(chu)現故障(zhang)斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian), 當故障(zhang)清除重(zhong)新送電(dian)(dian)(dian)(dian)(dian)以(yi)(yi)后,充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)又會(hui)開(kai)始(shi)重(zhong)新一(yi)輪的(de)四(si)小時(shi)(shi)固定充(chong)電(dian)(dian)(dian)(dian)(dian),從而造成電(dian)(dian)(dian)(dian)(dian)池(chi)過(guo)充(chong)四(si)個小時(shi)(shi).這種結果往往會(hui)對電(dian)(dian)(dian)(dian)(dian)池(chi) 造成損壞。因此原因,定時(shi)(shi)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)很(hen)少被(bei)采用(yong)。）

充電時可充電池應備條件

當電(dian)(dian)(dian)(dian)池連(lian)接上(shang)充(chong)(chong)電(dian)(dian)(dian)(dian)器以(yi)后(hou),此(ci)充(chong)(chong)電(dian)(dian)(dian)(dian)階段之充(chong)(chong)電(dian)(dian)(dian)(dian)器要能夠有所感應(ying)(ying)顯(xian)示(shi)以(yi)及彼電(dian)(dian)(dian)(dian)池是否可以(yi)進行(xing)充(chong)(chong)電(dian)(dian)(dian)(dian).一般當充(chong)(chong)電(dian)(dian)(dian)(dian)器電(dian)(dian)(dian)(dian)源關斷(duan)(duan) 的(de)(de)(de)情(qing)(qing)況下,此(ci)電(dian)(dian)(dian)(dian)池感應(ying)(ying)裝置(zhi)通(tong)常(chang)根據(ju)(ju)充(chong)(chong)電(dian)(dian)(dian)(dian)器接頭的(de)(de)(de)端口電(dian)(dian)(dian)(dian)壓(ya)來(lai)進行(xing)判斷(duan)(duan),但當電(dian)(dian)(dian)(dian)池已(yi)經反(fan)復過度使用或(huo)端口電(dian)(dian)(dian)(dian)壓(ya)極低的(de)(de)(de)情(qing)(qing)況下, 這種(zhong)(zhong)感應(ying)(ying)裝置(zhi)往往會產生問題(ti).作為一種(zhong)(zhong)替代方法,充(chong)(chong)電(dian)(dian)(dian)(dian)器經常(chang)根據(ju)(ju)溫度或(huo)電(dian)(dian)(dian)(dian)壓(ya)瞬時跳(tiao)變來(lai)達到上(shang)述目的(de)(de)(de).這種(zhong)(zhong)硬件設置(zhi)同樣(yang)適 用于電(dian)(dian)(dian)(dian)池組.

一(yi)(yi)旦充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器感(gan)應(ying)(ying)連接到(dao)了可充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi),它還必須判斷出電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是(shi)否具(ju)(ju)備良好可充(chong)條(tiao)件.在(zai)這個次(ci)級階段(duan)[限定條(tiao)件],電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)要能夠 被檢測出其(qi)基本(ben)功能狀態(tai);開(kai)路,短路,高溫或(huo)是(shi)低溫.以此來檢測電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是(shi)否具(ju)(ju)備可充(chong)性,一(yi)(yi)些(xie)鉛酸充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器類型(xing)特別(bie)需要一(yi)(yi)個可通過 LED燈來顯(xian)示出其(qi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)主充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)流[大約以五分之一(yi)(yi)的(de)(de)(de)快充(chong)額定電(dian)(dian)(dian)(dian)(dian)(dian)流],并允許電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)一(yi)(yi)固(gu)定充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)段(duan)內達(da)到(dao)其(qi)特定的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓. 這種(zhong)技術對已經反復過度使(shi)用的(de)(de)(de)鉛酸[PbSO4]蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi),應(ying)(ying)避免出現(xian)反接的(de)(de)(de)問題.

對(dui)外(wai)圍設備和(he)電池(chi)溫度(du)(du)的(de)(de)檢(jian)測也是本階(jie)段(duan)必要(yao)條件之一(yi).當充電器(qi)檢(jian)測到電池(chi)的(de)(de)溫度(du)(du)過(guo)(guo)高或過(guo)(guo)低(di),一(yi)般會等待(dai)一(yi)段(duan)預先設定(ding)的(de)(de) 時(shi)間(jian)以(yi)使其恢復正常(chang)(chang).如在(zai)設定(ding)時(shi)間(jian)內并(bing)未恢復正常(chang)(chang),充電器(qi)會自動改變充電電流,這個動作相(xiang)應就(jiu)調整(zheng)了(le)電池(chi)溫度(du)(du),所以(yi)充電效率 會大大增(zeng)加.最后(hou),充電器(qi)需要(yao)檢(jian)測一(yi)下與(yu)電池(chi)的(de)(de)連接狀(zhuang)(zhuang)態是開路(lu)抑或短路(lu).通常(chang)(chang)開路(lu)狀(zhuang)(zhuang)態容易檢(jian)測,而一(yi)旦出(chu)現短路(lu)顯示,就(jiu)需要(yao)進(jin) 一(yi)步(bu)確認,以(yi)避免(mian)造成(cheng)事故的(de)(de)發生.如果所有檢(jian)測都獲得(de)通過(guo)(guo),就(jiu)可(ke)以(yi)給電池(chi)充電了(le).這種設置相(xiang)當領先,請參(can)閱附圖1

預先充電條件設置[自選類型]

有(you)一(yi)些充(chong)電(dian)(dian)(dian)器[如(ru)早期(qi)出(chu)現(xian)的(de)(de)(de)鎳鎘(ge)電(dian)(dian)(dian)池]都設計(ji)有(you)一(yi)個充(chong)電(dian)(dian)(dian)前期(qi)預測階段(duan),用以判斷(duan)在(zai)重新充(chong)電(dian)(dian)(dian)前，待(dai)測電(dian)(dian)(dian)池是(shi)否已‘完(wan)全’放(fang)電(dian)(dian)(dian). 所謂‘完(wan)全’放(fang)電(dian)(dian)(dian)系指(zhi)每節電(dian)(dian)(dian)池的(de)(de)(de)端口電(dian)(dian)(dian)壓放(fang)電(dian)(dian)(dian)到(dao)1V的(de)(de)(de)水(shui)平,以去除電(dian)(dian)(dian)解(jie)液(ye)(ye)中的(de)(de)(de)枝狀(zhuang)結(jie)構,這也(ye)是(shi)人們(men)為什(shen)么經(jing)常(chang)錯誤地理解(jie)‘記憶 效應(ying)’的(de)(de)(de)原因[通常(chang)電(dian)(dian)(dian)池一(yi)次(ci)可充(chong)電(dian)(dian)(dian)容(rong)量(liang)是(shi)上次(ci)放(fang)電(dian)(dian)(dian)容(rong)量(liang)的(de)(de)(de)104—110百(bai)分比(bi)].這種所謂的(de)(de)(de)‘記憶效應(ying)’特指(zhi)電(dian)(dian)(dian)池內部電(dian)(dian)(dian)解(jie)液(ye)(ye)枝狀(zhuang)結(jie) 構狀(zhuang)態的(de)(de)(de)自我恢復(fu)能(neng)力,如(ru)受(shou)到(dao)破壞,將減少電(dian)(dian)(dian)池的(de)(de)(de)使用壽命(ming).所以按正常(chang)時間(jian)周期(qi)進行的(de)(de)(de)充(chong)放(fang)電(dian)(dian)(dian),往往會解(jie)決這個問(wen)題.

在每(mei)次(ci)充(chong)電前,此(ci)預(yu)測(ce)階(jie)段都會(hui)被自動(dong)(dong)完(wan)成(cheng),或在電池充(chong)電剩(sheng)余過半顯示[通(tong)(tong)過連接(jie)測(ce)試或其它操作]之后.預(yu)測(ce)階(jie)段一般從(cong)一到十(shi)小 時(shi)(shi)不等(deng).在一小時(shi)(shi)之內放空電池通(tong)(tong)常不予考慮.而(er)通(tong)(tong)過連接(jie)電阻縮短預(yu)測(ce)階(jie)段時(shi)(shi)間,會(hui)產(chan)生散熱困難的問題(ti).而(er)大于十(shi)小時(shi)(shi)的階(jie)段設(she)計 也往(wang)往(wang)不被采用,除非可(ke)以(yi)用手動(dong)(dong)方(fang)式(shi)開始探測(ce)減(jian)少的電池容(rong)量.因此(ci),由于對(dui)鎳鎘(ge)電池’記憶效應’的不知和(he)種種誤解,設(she)計人員應 避(bi)免在充(chong)電器上設(she)置(zhi)相關按鈕(niu)來與此(ci)’效應’進行(xing)對(dui)抗.

快充階段及充電終止

快充(chong)和終止充(chong)電(dian)方式使(shi)用(yong)(yong)要根據蓄(xu)電(dian)池及(ji)其它設(she)計因素考慮.以(yi)下(xia)探討(tao)涉及(ji)到當今通用(yong)(yong)蓄(xu)電(dian)池快充(chong)技(ji)術的全面使(shi)用(yong)(yong).如(ru)需詳細(xi)建(jian) 議資料,可與(yu)電(dian)池制(zhi)造商(shang)應用(yong)(yong)部門聯系查(cha)詢.

鎳鎘,鎳氫蓄電池

鎳(nie)鎘(ge)和(he)鎳(nie)氫蓄電(dian)(dian)(dian)池(chi)的(de)(de)快充程序(xu)非常(chang)類(lei)似,主要(yao)區(qu)別(bie)在于(yu)充電(dian)(dian)(dian)的(de)(de)終止階段(duan).在每一(yi)個樣例(li)中,當充電(dian)(dian)(dian)器監測(ce)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓及其(qi)它數據,以(yi)(yi) 判斷何時終止充電(dian)(dian)(dian)時,都需要(yao)一(yi)個恒定(ding)電(dian)(dian)(dian)流(liu).超過2C的(de)(de)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)是(shi)(shi)可以(yi)(yi)做到(dao)的(de)(de),但一(yi)般最常(chang)用C/2左右(you)的(de)(de)電(dian)(dian)(dian)流(liu).因充電(dian)(dian)(dian)效率無(wu)論(lun)怎(zen)樣都 要(yao)小于(yu)100%, 所(suo)以(yi)(yi)用C/2電(dian)(dian)(dian)流(liu)稍多于(yu)兩個小時的(de)(de)全充是(shi)(shi)可以(yi)(yi)被接(jie)受(shou)的(de)(de).

在恒流充電(dian)(dian)(dian)階段,電(dian)(dian)(dian)池(chi)端口(kou)電(dian)(dian)(dian)壓緩慢(man)上升,最(zui)終(zhong)到(dao)達頂點(dian)(dian)[即(ji)坡度(du)為零的(de)電(dian)(dian)(dian)壓最(zui)高點(dian)(dian)].鎳(nie)氫電(dian)(dian)(dian)池(chi)應(ying)在此點(dian)(dian)[0DV點(dian)(dian)]終(zhong)止充電(dian)(dian)(dian).而鎳(nie)鎘 電(dian)(dian)(dian)池(chi)則應(ying)在此點(dian)(dian)之后某(mou)點(dian)(dian)[系電(dian)(dian)(dian)池(chi)端口(kou)電(dian)(dian)(dian)壓首次出(chu)現微小降低點(dian)(dian)即(ji)-DV點(dian)(dian)]結束(shu),請參閱圖(tu)2,可允許有少(shao)部(bu)分過充.快(kuai)充如超(chao)過這兩個設 定關斷(duan)點(dian)(dian)[最(zui)高電(dian)(dian)(dian)壓點(dian)(dian)和略小的(de)-DV點(dian)(dian)],都會對電(dian)(dian)(dian)池(chi)造成損壞.這是因為快(kuai)充電(dian)(dian)(dian)流遠大于正常慢(man)充狀態(tai)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)流充(chong)電(dian)(dian)[充(chong)電(dian)(dian)時(shi)間不會(hui)超過兩個小時(shi)],充(chong)電(dian)(dian)器仍要監(jian)測(ce)(ce)電(dian)(dian)池(chi)溫(wen)(wen)度(du)(du)(du)和(he)電(dian)(dian)壓(ya)(ya).因(yin)為(wei)當電(dian)(dian)池(chi)充(chong)滿時(shi),電(dian)(dian)池(chi)溫(wen)(wen)度(du)(du)(du)將上升很(hen)快,所以 溫(wen)(wen)度(du)(du)(du)監(jian)測(ce)(ce)元件要啟動另一關(guan)斷(duan)(duan)(duan)裝(zhuang)置.在這正向(xiang)上升溫(wen)(wen)度(du)(du)(du)曲線上的(de)關(guan)斷(duan)(duan)(duan)點被稱為(wei)T關(guan)斷(duan)(duan)(duan)點.除溫(wen)(wen)度(du)(du)(du)關(guan)斷(duan)(duan)(duan)外,其它監(jian)測(ce)(ce)數據,包括已充(chong)時(shi)間,最(zui) 大限定(ding)電(dian)(dian)池(chi)保護電(dian)(dian)壓(ya)(ya),都可(ke)參預充(chong)電(dian)(dian)器關(guan)斷(duan)(duan)(duan).所以設(she)計成功的(de)充(chong)電(dian)(dian)器自動關(guan)斷(duan)(duan)(duan)應(ying)依據這幾種監(jian)測(ce)(ce)因(yin)素(su)[溫(wen)(wen)度(du)(du)(du)關(guan)斷(duan)(duan)(duan),充(chong)電(dian)(dian)時(shi)間關(guan)斷(duan)(duan)(duan),電(dian)(dian)池(chi)最(zui)大 限定(ding)電(dian)(dian)壓(ya)(ya)關(guan)斷(duan)(duan)(duan)等]的(de)組合.

備注;當電池首(shou)次充(chong)電,會(hui)(hui)產(chan)生(sheng)模(mo)仿關(guan)斷(duan)狀態的(de)特定效(xiao)應,因此在激活關(guan)斷(duan)模(mo)式監(jian)測(ce)曲線前,充(chong)電器(qi)會(hui)(hui)引入一(yi)(yi)個 一(yi)(yi)到(dao)五(wu)分(fen)鐘的(de)緩沖期(qi).另外,充(chong)電關(guan)斷(duan)狀態在低于C\8電流(liu)充(chong)電時(shi)很(hen)(hen)難監(jian)測(ce)到(dao)數據(ju),這是因為與其(qi)他系(xi)統(tong)(tong)數據(ju)比(bi)較, 電壓和溫度曲線[V/t和T/t]斜率很(hen)(hen)小所(suo)致.為快速充(chong)電的(de)安全起見,這些系(xi)統(tong)(tong)中的(de)硬軟件配置總是會(hui)(hui)造成(cheng)充(chong)電器(qi)提 前關(guan)斷(duan)的(de)誤操作動作.

 

鋰離子電池

鋰(li)離(li)(li)子蓄(xu)電(dian)池(chi)充電(dian)曲線和鎳離(li)(li)子蓄(xu)電(dian)池(chi)相比(bi)很(hen)不一樣(yang).充電(dian)關(guan)斷要確(que)定到最(zui)大(da)安全值之后才會動(dong)作(zuo).鋰(li)電(dian)充電(dian)器要將充電(dian)電(dian)壓(ya)控制 在小于(yu)0.75%的精確(que)范圍內,并且其(qi)最(zui)大(da)充電(dian)效率(lv)用充電(dian)電(dian)流(liu)限定控制,非(fei)常類(lei)似臺式桌面型直流(liu)電(dian)源. 當(dang)快充開(kai)始時,電(dian)池(chi)端(duan)口電(dian)壓(ya)相 對較(jiao)低,充電(dian)電(dian)流(liu)就等同于(yu)其(qi)限定電(dian)流(liu)值.

在充電(dian)過程中,電(dian)池電(dian)壓(ya)緩慢上(shang)(shang)升.最后,充電(dian)電(dian)流到(dao)達設定峰值,充電(dian)電(dian)壓(ya)上(shang)(shang)升到(dao)每節(jie) 4.2V的浮充電(dian)壓(ya)水平[見(jian)圖(tu)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)到浮充(chong)電(dian)(dian)(dian)(dian)壓水平(ping),充(chong)電(dian)(dian)(dian)(dian)器就可以終(zhong)止充(chong)電(dian)(dian)(dian)(dian)了(le),但這(zhe)種方式忽略了(le)充(chong)電(dian)(dian)(dian)(dian)峰頂值關(guan)斷(duan)操作(zuo).如在(zai)(zai)浮充(chong)電(dian)(dian)(dian)(dian)壓階段(duan),充(chong)電(dian)(dian)(dian)(dian)器會開始 定時器的操作(zuo),在(zai)(zai)一(yi)段(duan)設定緩沖(chong)期后,自(zi)動終(zhong)止充(chong)電(dian)(dian)(dian)(dian).另(ling)一(yi)方式,也可監測(ce)充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu),在(zai)(zai)一(yi)個較低電(dian)(dian)(dian)(dian)流(liu)(liu)水平(ping)關(guan)斷(duan)[典型地用(yong)0.05的限定值, 一(yi)些制造商建議使用(yong)相對(dui)較高的100mA電(dian)(dian)(dian)(dian)流(liu)(liu)最小值].充(chong)電(dian)(dian)(dian)(dian)峰值關(guan)斷(duan)環(huan)路往(wang)往(wang)也依(yi)靠這(zhe)種技術.

最近幾年,在鋰(li)(li)離(li)子(zi)電池和其(qi)充(chong)電器,以(yi)及(ji)對這(zhe)種新型電池的(de)了解方面,都取得了相當(dang)(dang)的(de)進展(zhan).最早(zao)期的(de)鋰(li)(li)離(li)子(zi)電池在用戶(hu)的(de)使(shi)用方 面都有(you)一些安全(quan)層(ceng)面的(de)缺點,而(er)這(zhe)些問題已不(bu)會出現在當(dang)(dang)今設(she)計成功的(de)系統上了.制造(zao)商們的(de)建議既不(bu)會一成不(bu)變(bian),也(ye)不(bu)會完全(quan)一致, 而(er)鋰(li)(li)離(li)子(zi)電池技術會繼續向前發展(zhan).

鋰聚(ju)合(he)物電池(chi)的(de)充電要求(qiu)和鋰離子(zi)電池(chi)的(de)要求(qiu)是(shi)一樣的(de)，可以按(an)同(tong)類對待。

最新出現(xian)的(de)磷酸鐵鋰電池的(de)電壓比鋰離子電池的(de)額度電壓要低(di)0.4V左右，充電的(de)恒壓電壓設定值為3.7V/節為宜(yi)。充電的(de)方式與 鋰離子電池基本相同（注意只是(shi)電壓要低(di)一(yi)些！）

 

鉛酸電池.

鉛酸[PbSO4]蓄電(dian)(dian)池既可以用(yong)限流(liu)充(chong)(chong)電(dian)(dian),也(ye)可以用(yong)較通用(yong)簡單的限壓(ya)充(chong)(chong)電(dian)(dian).限壓(ya)充(chong)(chong)電(dian)(dian)與前者具有類(lei)似的作用(yong)功能(neng),而高(gao)精(jing)確性并非是 其關鍵.這需要設置一個(ge)高(gao)于(yu)電(dian)(dian)池浮(fu)充(chong)(chong)電(dian)(dian)壓(ya)的限流(liu)電(dian)(dian)壓(ya)源[大約2.45V左(zuo)右].

經(jing)過預設狀態操作,充(chong)(chong)電(dian)(dian)器確認開(kai)始快充(chong)(chong),一(yi)直延(yan)續到最小充(chong)(chong)電(dian)(dian)電(dian)(dian)流[這個過程(cheng)類似鋰離子(zi)電(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)器],然后快充(chong)(chong)終(zhong)止(zhi).這時充(chong)(chong)電(dian)(dian)器 需(xu)要(yao)一(yi)段Vf浮(fu)充(chong)(chong)電(dian)(dian)壓(ya)進(jin)行維護[通常用(yong)2.25V左右(you)電(dian)(dian)壓(ya)].鉛酸[PbSO4]蓄電(dian)(dian)池(chi)允許在非確定(ding)階(jie)段用(yong)此浮(fu)充(chong)(chong)電(dian)(dian)壓(ya)進(jin)行維護[見(jian)圖5].

圖5.鉛酸[PbSO4]蓄電池充電簡圖.

 

在高溫環(huan)境(jing)下,對鉛(qian)酸[PbSO4]蓄電(dian)池進行快(kuai)充(chong)的電(dian)流要根據每攝(she)氏度(du)0.3百(bai)分比的標準溫度(du)系數(shu)進行調低.快(kuai)充(chong)時設定最大電(dian)池溫度(du) 建(jian)議在50’C左右,但浮充(chong)一般可以超過(guo)這個溫度(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)(dian)(dian)(dian)池(chi)(chi)外,其它(ta)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器經常設置有一個可供選(xuan)擇的涓(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段.這個階段的設置可以用來補(bu)償電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)滿后本體(ti)的自放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian) 現象(xiang).鉛(qian)酸(suan)[PbSO4]電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)自放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)最大[每(mei)天呈數個百(bai)分點],而鋰(li)離子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)最低.鋰(li)離子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的自放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)有時低到已(yi)無(wu)需涓(juan)充(chong)(chong)來維護(hu).然而, 鎳鎘[NiCds]蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)卻經常,不定地需要C/16的涓(juan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)以進(jin)行維護(hu).對鎳氫[NiMH]蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)而言,安(an)全的持續放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)經常在C/50左(zuo)右,而涓(juan) 流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)一般不被建議.

續放電電流(liu)經(jing)常(chang)在(zai)C/50左右,而涓 流(liu)充電一(yi)般不被建議.