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 充電方(fang)法在(zai)充電初期電池內阻(zu)極低致使充電電流過大，而隨時(shi)間(jian)并(bing)不(bu)按指數規律下降常偏離制定曲線

 

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(ren)意時刻總 存在一個最佳的充電電流(liu)和充電模式的，問題是我們如何才能(neng)逼近這個最佳值。 

綜合起來(lai)，判斷規則有如下幾種：

●定時控制；

●電(dian)壓控制(含最高電(dian)壓：電(dian)壓負(fu)增量(liang)：電(dian)壓零增量(liang)等)；

●溫(wen)(wen)(wen)度(du)控制(包括最高(gao)溫(wen)(wen)(wen)度(du)，最高(gao)溫(wen)(wen)(wen)升：溫(wen)(wen)(wen)度(du)變化(hua)率等)；

●電流控制等。

較好(hao)的辦法是(shi)采用綜合判斷方法，對(dui)每個指(zhi)標進行(xing)跟蹤，并按模(mo)糊數學(xue)原(yuan)理分別記分，按照置信度做出(chu)最佳判斷。 電池快速充電分為幾個階段,見本文(wen)所述及通用充電器運行(xing)簡圖(tu)(tu).[圖(tu)(tu)1]

　

 

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

 

起始階段

起(qi)始(shi)階(jie)段在(zai)(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過(guo)程中雖不屬(shu)于真正起(qi)作用的(de)那(nei)幾個(ge)階(jie)段,但在(zai)(zai)整個(ge)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過(guo)程中,起(qi)始(shi)階(jie)段仍是一個(ge)非常重要(yao)(yao)的(de)滿足條件. 充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)啟動(dong)以(yi)(yi)(yi)后開始(shi)自(zi)測(ce),如電(dian)(dian)(dian)源(yuan)(yuan)(yuan)出現(xian)(xian)(xian)故障(zhang)或反復起(qi)動(dong),充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過(guo)程就會被打斷(duan).如果缺乏相應智(zhi)能(neng)(neng)或時(shi)(shi)(shi)間(jian)關斷(duan)裝置以(yi)(yi)(yi)及電(dian)(dian)(dian)池(chi)(chi)(chi)密 封(feng)性能(neng)(neng)不能(neng)(neng)得到改善(shan),那(nei)么此種(zhong)現(xian)(xian)(xian)象(xiang)往(wang)往(wang)會被忽(hu)視.幾乎所有的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)在(zai)(zai)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)出現(xian)(xian)(xian)故障(zhang)以(yi)(yi)(yi)后都可(ke)以(yi)(yi)(yi)完(wan)全重新啟動(dong),但如過(guo)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)(neng)夠進行(xing)特別的(de)自(zi)測(ce)程序(xu)以(yi)(yi)(yi)判(pan)斷(duan)電(dian)(dian)(dian)池(chi)(chi)(chi)是否早已(yi)充(chong)(chong)(chong)(chong)滿.電(dian)(dian)(dian)池(chi)(chi)(chi)狀(zhuang)態要(yao)(yao)顯(xian)現(xian)(xian)(xian)在(zai)(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)指示(shi)(shi)燈或類(lei)似的(de)顯(xian)示(shi)(shi)裝置上(shang). （不好的(de)案例(li)：例(li)如只靠定時(shi)(shi)(shi)的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi),用四(si)個(ge)小(xiao)(xiao)時(shi)(shi)(shi)間(jian)隔的(de)固定時(shi)(shi)(shi)間(jian)給(gei)電(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian).如果充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)三小(xiao)(xiao)時(shi)(shi)(shi)59分鐘(zhong),電(dian)(dian)(dian)源(yuan)(yuan)(yuan)出現(xian)(xian)(xian)故障(zhang)斷(duan)電(dian)(dian)(dian), 當故障(zhang)清除重新送電(dian)(dian)(dian)以(yi)(yi)(yi)后,充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)又會開始(shi)重新一輪的(de)四(si)小(xiao)(xiao)時(shi)(shi)(shi)固定充(chong)(chong)(chong)(chong)電(dian)(dian)(dian),從而造成電(dian)(dian)(dian)池(chi)(chi)(chi)過(guo)充(chong)(chong)(chong)(chong)四(si)個(ge)小(xiao)(xiao)時(shi)(shi)(shi).這(zhe)種(zhong)結果往(wang)往(wang)會對電(dian)(dian)(dian)池(chi)(chi)(chi) 造成損(sun)壞。因此原因,定時(shi)(shi)(shi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)很少被采用。）

充電時可充電池應備條件

當(dang)電(dian)(dian)(dian)池連接上充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)以后,此(ci)充(chong)(chong)電(dian)(dian)(dian)階(jie)段(duan)之充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)要能夠有(you)所感(gan)應顯示以及(ji)彼電(dian)(dian)(dian)池是否(fou)可以進行(xing)充(chong)(chong)電(dian)(dian)(dian).一(yi)般當(dang)充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)電(dian)(dian)(dian)源(yuan)關(guan)斷(duan) 的情況(kuang)下,此(ci)電(dian)(dian)(dian)池感(gan)應裝置(zhi)通常根據(ju)充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)接頭的端口(kou)電(dian)(dian)(dian)壓來(lai)進行(xing)判斷(duan),但當(dang)電(dian)(dian)(dian)池已經反復過度使用或端口(kou)電(dian)(dian)(dian)壓極低(di)的情況(kuang)下, 這(zhe)種(zhong)感(gan)應裝置(zhi)往往會產(chan)生問題.作(zuo)為一(yi)種(zhong)替代方法,充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)經常根據(ju)溫度或電(dian)(dian)(dian)壓瞬時跳變來(lai)達到上述目的.這(zhe)種(zhong)硬件設置(zhi)同樣適 用于(yu)電(dian)(dian)(dian)池組.

一(yi)(yi)旦(dan)充(chong)(chong)電(dian)器感應(ying)連接到了可充(chong)(chong)電(dian)電(dian)池(chi)(chi),它(ta)還必(bi)須判斷出電(dian)池(chi)(chi)是否(fou)具(ju)備良好可充(chong)(chong)條(tiao)件.在(zai)這(zhe)個次(ci)級階段(duan)(duan)[限定條(tiao)件],電(dian)池(chi)(chi)要能(neng)夠 被檢測出其(qi)基本功能(neng)狀態;開路,短路,高溫或是低溫.以此來檢測電(dian)池(chi)(chi)是否(fou)具(ju)備可充(chong)(chong)性,一(yi)(yi)些鉛(qian)酸充(chong)(chong)電(dian)器類型特(te)別需要一(yi)(yi)個可通(tong)過 LED燈(deng)來顯示出其(qi)充(chong)(chong)電(dian)的(de)(de)主(zhu)充(chong)(chong)電(dian)流(liu)[大約以五分(fen)之一(yi)(yi)的(de)(de)快(kuai)充(chong)(chong)額定電(dian)流(liu)],并允(yun)許(xu)電(dian)池(chi)(chi)在(zai)一(yi)(yi)固定充(chong)(chong)電(dian)時(shi)間(jian)段(duan)(duan)內(nei)達到其(qi)特(te)定的(de)(de)電(dian)池(chi)(chi)電(dian)壓. 這(zhe)種(zhong)技(ji)術對(dui)已(yi)經反復過度使(shi)用的(de)(de)鉛(qian)酸[PbSO4]蓄電(dian)池(chi)(chi),應(ying)避(bi)免出現反接的(de)(de)問題.

對(dui)外(wai)圍設(she)備和電(dian)(dian)(dian)(dian)池(chi)(chi)溫度(du)的檢(jian)測也是本階段必要(yao)(yao)條件之一.當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)檢(jian)測到電(dian)(dian)(dian)(dian)池(chi)(chi)的溫度(du)過高或過低(di),一般(ban)會(hui)等待一段預先設(she)定的 時間以使其(qi)恢復(fu)正(zheng)常.如在(zai)設(she)定時間內并未(wei)恢復(fu)正(zheng)常,充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)會(hui)自動改變充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流,這個(ge)動作相應(ying)就調(diao)整(zheng)了(le)電(dian)(dian)(dian)(dian)池(chi)(chi)溫度(du),所(suo)以充(chong)(chong)電(dian)(dian)(dian)(dian)效率 會(hui)大(da)大(da)增加(jia).最后,充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)需(xu)要(yao)(yao)檢(jian)測一下與(yu)電(dian)(dian)(dian)(dian)池(chi)(chi)的連接狀(zhuang)態是開路(lu)抑或短路(lu).通常開路(lu)狀(zhuang)態容易檢(jian)測,而一旦出現短路(lu)顯示(shi),就需(xu)要(yao)(yao)進 一步確認,以避免(mian)造成事(shi)故的發生(sheng).如果所(suo)有檢(jian)測都(dou)獲(huo)得通過,就可以給電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)了(le).這種設(she)置(zhi)相當(dang)領先,請參閱附(fu)圖1

預先充電條件設置[自選類型]

有一些充電(dian)(dian)(dian)(dian)器(qi)[如早期出(chu)現(xian)的(de)(de)(de)(de)鎳鎘(ge)電(dian)(dian)(dian)(dian)池]都設計有一個充電(dian)(dian)(dian)(dian)前期預(yu)測階段,用以(yi)判斷(duan)在重新充電(dian)(dian)(dian)(dian)前，待測電(dian)(dian)(dian)(dian)池是(shi)否已‘完全(quan)’放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian). 所謂‘完全(quan)’放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)系指(zhi)每節電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)端口(kou)電(dian)(dian)(dian)(dian)壓(ya)放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)到1V的(de)(de)(de)(de)水平,以(yi)去除電(dian)(dian)(dian)(dian)解液(ye)中的(de)(de)(de)(de)枝狀(zhuang)結(jie)構,這(zhe)也是(shi)人們(men)為什么經常錯誤地理解‘記(ji)憶 效應’的(de)(de)(de)(de)原因[通常電(dian)(dian)(dian)(dian)池一次可充電(dian)(dian)(dian)(dian)容量(liang)是(shi)上次放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)容量(liang)的(de)(de)(de)(de)104—110百分比].這(zhe)種所謂的(de)(de)(de)(de)‘記(ji)憶效應’特(te)指(zhi)電(dian)(dian)(dian)(dian)池內部電(dian)(dian)(dian)(dian)解液(ye)枝狀(zhuang)結(jie) 構狀(zhuang)態的(de)(de)(de)(de)自我恢復能力,如受(shou)到破壞,將減少電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)使用壽命(ming).所以(yi)按正常時間周期進行(xing)的(de)(de)(de)(de)充放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian),往(wang)往(wang)會解決這(zhe)個問題.

在(zai)每次充(chong)電(dian)前,此(ci)預測(ce)(ce)階(jie)段(duan)(duan)都會(hui)被自動(dong)完成,或在(zai)電(dian)池(chi)充(chong)電(dian)剩余(yu)過半顯示(shi)[通(tong)過連接測(ce)(ce)試或其它操作]之后.預測(ce)(ce)階(jie)段(duan)(duan)一(yi)般(ban)從一(yi)到十小(xiao) 時(shi)不(bu)等.在(zai)一(yi)小(xiao)時(shi)之內放空(kong)電(dian)池(chi)通(tong)常不(bu)予(yu)考慮.而通(tong)過連接電(dian)阻縮(suo)短(duan)預測(ce)(ce)階(jie)段(duan)(duan)時(shi)間,會(hui)產(chan)生散熱困難的問題(ti).而大于十小(xiao)時(shi)的階(jie)段(duan)(duan)設(she)計 也往(wang)往(wang)不(bu)被采(cai)用,除(chu)非(fei)可以用手動(dong)方式開始探測(ce)(ce)減少(shao)的電(dian)池(chi)容(rong)量.因此(ci),由于對(dui)(dui)鎳鎘電(dian)池(chi)’記憶效應’的不(bu)知和種種誤解,設(she)計人(ren)員(yuan)應 避免在(zai)充(chong)電(dian)器上設(she)置(zhi)相(xiang)關(guan)按鈕來與此(ci)’效應’進行(xing)對(dui)(dui)抗.

快充階段及充電終止

快(kuai)充(chong)和終止充(chong)電方式使用要根據蓄電池及(ji)其它設計(ji)因素考慮.以下探討(tao)涉及(ji)到當今通用蓄電池快(kuai)充(chong)技術的全面使用.如需詳細建 議(yi)資料,可與電池制(zhi)造(zao)商應(ying)用部門聯系查詢(xun).

鎳鎘,鎳氫蓄電池

鎳鎘和鎳氫蓄電(dian)(dian)(dian)(dian)(dian)池的(de)(de)快充(chong)程序非常類(lei)似(si),主要(yao)(yao)區別在于充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)終止階(jie)段.在每一(yi)個樣例中(zhong),當充(chong)電(dian)(dian)(dian)(dian)(dian)器監測電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓及其它數據,以 判斷何時(shi)終止充(chong)電(dian)(dian)(dian)(dian)(dian)時(shi),都需要(yao)(yao)一(yi)個恒定電(dian)(dian)(dian)(dian)(dian)流(liu)(liu).超過2C的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)是可以做到的(de)(de),但一(yi)般最常用(yong)(yong)C/2左右的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu).因(yin)充(chong)電(dian)(dian)(dian)(dian)(dian)效率無(wu)論怎樣都 要(yao)(yao)小于100%, 所以用(yong)(yong)C/2電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)稍多于兩個小時(shi)的(de)(de)全充(chong)是可以被接受的(de)(de).

在恒流(liu)充電(dian)(dian)階段(duan),電(dian)(dian)池(chi)(chi)端(duan)口電(dian)(dian)壓(ya)(ya)緩(huan)慢上升,最(zui)終到達頂點(dian)[即坡(po)度為零(ling)的電(dian)(dian)壓(ya)(ya)最(zui)高點(dian)].鎳氫電(dian)(dian)池(chi)(chi)應在此點(dian)[0DV點(dian)]終止充電(dian)(dian).而鎳鎘 電(dian)(dian)池(chi)(chi)則(ze)應在此點(dian)之后某(mou)點(dian)[系(xi)電(dian)(dian)池(chi)(chi)端(duan)口電(dian)(dian)壓(ya)(ya)首次出現微小(xiao)降低點(dian)即-DV點(dian)]結束,請(qing)參閱圖2,可允許(xu)有少(shao)部分過充.快充如(ru)超過這兩個設(she) 定關斷點(dian)[最(zui)高電(dian)(dian)壓(ya)(ya)點(dian)和(he)略小(xiao)的-DV點(dian)],都會對電(dian)(dian)池(chi)(chi)造成損壞(huai).這是因(yin)為快充電(dian)(dian)流(liu)遠大于正常慢充狀態(tai)所致(zhi).

圖2.對鎳鎘電池用C/2電流進行充電的參數特性

以大于(yu)C/2電(dian)(dian)流充(chong)電(dian)(dian)[充(chong)電(dian)(dian)時間(jian)不會超過(guo)兩(liang)個小時],充(chong)電(dian)(dian)器(qi)仍要監測(ce)電(dian)(dian)池(chi)溫度(du)和(he)電(dian)(dian)壓(ya).因(yin)為當電(dian)(dian)池(chi)充(chong)滿時,電(dian)(dian)池(chi)溫度(du)將上(shang)升很(hen)快,所以 溫度(du)監測(ce)元(yuan)件要啟動(dong)另一關(guan)(guan)(guan)斷(duan)(duan)裝置.在(zai)這正向上(shang)升溫度(du)曲(qu)線上(shang)的關(guan)(guan)(guan)斷(duan)(duan)點(dian)被稱為T關(guan)(guan)(guan)斷(duan)(duan)點(dian).除(chu)溫度(du)關(guan)(guan)(guan)斷(duan)(duan)外,其它監測(ce)數(shu)據(ju),包括(kuo)已充(chong)時間(jian),最(zui)(zui) 大限(xian)定(ding)電(dian)(dian)池(chi)保護電(dian)(dian)壓(ya),都可參預充(chong)電(dian)(dian)器(qi)關(guan)(guan)(guan)斷(duan)(duan).所以設(she)計成功(gong)的充(chong)電(dian)(dian)器(qi)自動(dong)關(guan)(guan)(guan)斷(duan)(duan)應依(yi)據(ju)這幾種監測(ce)因(yin)素(su)[溫度(du)關(guan)(guan)(guan)斷(duan)(duan),充(chong)電(dian)(dian)時間(jian)關(guan)(guan)(guan)斷(duan)(duan),電(dian)(dian)池(chi)最(zui)(zui)大 限(xian)定(ding)電(dian)(dian)壓(ya)關(guan)(guan)(guan)斷(duan)(duan)等(deng)]的組合(he).

備注;當電(dian)池(chi)首次充(chong)電(dian),會產生模仿關(guan)斷(duan)狀態的特定效應(ying),因此在激活關(guan)斷(duan)模式(shi)監(jian)測(ce)曲線前(qian),充(chong)電(dian)器會引入(ru)一(yi)個 一(yi)到五(wu)分鐘的緩沖期.另外,充(chong)電(dian)關(guan)斷(duan)狀態在低于(yu)C\8電(dian)流充(chong)電(dian)時很難監(jian)測(ce)到數據,這(zhe)是(shi)(shi)因為與其他系統數據比(bi)較, 電(dian)壓和溫度曲線[V/t和T/t]斜(xie)率很小(xiao)所致.為快速充(chong)電(dian)的安全起見,這(zhe)些系統中的硬(ying)軟件配置(zhi)總是(shi)(shi)會造成(cheng)充(chong)電(dian)器提 前(qian)關(guan)斷(duan)的誤操作動作.

 

鋰離子電池

鋰離子蓄(xu)電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)曲線(xian)和鎳(nie)離子蓄(xu)電(dian)(dian)(dian)池(chi)相比很(hen)不一樣(yang).充(chong)(chong)(chong)電(dian)(dian)(dian)關斷要確定到最大(da)安全值(zhi)之后(hou)才會動作.鋰電(dian)(dian)(dian)充(chong)(chong)(chong)電(dian)(dian)(dian)器要將充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)控制 在小于0.75%的精確范圍(wei)內,并且(qie)其最大(da)充(chong)(chong)(chong)電(dian)(dian)(dian)效率(lv)用充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流限(xian)定控制,非常類似臺式(shi)桌面型直(zhi)流電(dian)(dian)(dian)源. 當快充(chong)(chong)(chong)開始時,電(dian)(dian)(dian)池(chi)端口(kou)電(dian)(dian)(dian)壓(ya)相 對(dui)較低,充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流就(jiu)等(deng)同于其限(xian)定電(dian)(dian)(dian)流值(zhi).

在充電過程中,電池(chi)電壓緩慢上升.最后,充電電流到達設(she)定峰(feng)值,充電電壓上升到每(mei)節(jie) 4.2V的(de)浮充電壓水(shui)平[見圖4]

圖4.鋰離子蓄電池充電簡圖.

當電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)到浮充(chong)(chong)電(dian)(dian)(dian)壓水平,充(chong)(chong)電(dian)(dian)(dian)器就可(ke)以終(zhong)止充(chong)(chong)電(dian)(dian)(dian)了(le),但這種(zhong)方式(shi)忽略了(le)充(chong)(chong)電(dian)(dian)(dian)峰(feng)頂值(zhi)關(guan)(guan)斷(duan)(duan)操作(zuo)(zuo).如在浮充(chong)(chong)電(dian)(dian)(dian)壓階段,充(chong)(chong)電(dian)(dian)(dian)器會(hui)開始(shi) 定時器的(de)操作(zuo)(zuo),在一(yi)段設定緩(huan)沖期后(hou),自(zi)動終(zhong)止充(chong)(chong)電(dian)(dian)(dian).另(ling)一(yi)方式(shi),也(ye)可(ke)監測充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu),在一(yi)個(ge)較低電(dian)(dian)(dian)流(liu)水平關(guan)(guan)斷(duan)(duan)[典型(xing)地(di)用0.05的(de)限定值(zhi), 一(yi)些制(zhi)造商建議使用相(xiang)對較高的(de)100mA電(dian)(dian)(dian)流(liu)最小(xiao)值(zhi)].充(chong)(chong)電(dian)(dian)(dian)峰(feng)值(zhi)關(guan)(guan)斷(duan)(duan)環(huan)路往往也(ye)依(yi)靠(kao)這種(zhong)技(ji)術.

最近幾年,在鋰離子電池(chi)和(he)其充電器,以及對(dui)這(zhe)種新型(xing)電池(chi)的(de)了(le)解(jie)方面(mian),都取得了(le)相(xiang)當的(de)進展.最早期的(de)鋰離子電池(chi)在用(yong)戶的(de)使用(yong)方 面(mian)都有一些(xie)安全(quan)層面(mian)的(de)缺(que)點,而這(zhe)些(xie)問(wen)題已不(bu)會(hui)出現在當今設計成(cheng)功的(de)系統(tong)上(shang)了(le).制造商們的(de)建議既不(bu)會(hui)一成(cheng)不(bu)變,也(ye)不(bu)會(hui)完全(quan)一致, 而鋰離子電池(chi)技術會(hui)繼續(xu)向前發展.

鋰聚合(he)物電(dian)池的充電(dian)要求和(he)鋰離子電(dian)池的要求是一樣的，可以按同類對待。

最(zui)新出現的(de)磷酸鐵鋰(li)電池(chi)的(de)電壓(ya)比鋰(li)離子電池(chi)的(de)額度電壓(ya)要低0.4V左右，充電的(de)恒(heng)壓(ya)電壓(ya)設(she)定值為(wei)3.7V/節為(wei)宜。充電的(de)方(fang)式與 鋰(li)離子電池(chi)基(ji)本相同（注意(yi)只是電壓(ya)要低一(yi)些(xie)！）

 

鉛酸電池.

鉛酸[PbSO4]蓄電(dian)(dian)池(chi)既可以(yi)(yi)用(yong)限(xian)(xian)(xian)流充(chong)電(dian)(dian),也可以(yi)(yi)用(yong)較(jiao)通用(yong)簡單的限(xian)(xian)(xian)壓充(chong)電(dian)(dian).限(xian)(xian)(xian)壓充(chong)電(dian)(dian)與(yu)前者(zhe)具有類似的作用(yong)功(gong)能,而高精確性并非是 其關鍵.這需要設置(zhi)一(yi)個高于電(dian)(dian)池(chi)浮充(chong)電(dian)(dian)壓的限(xian)(xian)(xian)流電(dian)(dian)壓源[大(da)約2.45V左右(you)].

經過預設狀(zhuang)態操作,充(chong)(chong)電(dian)器(qi)確(que)認開始快(kuai)充(chong)(chong),一直延續到最小充(chong)(chong)電(dian)電(dian)流(liu)[這個過程(cheng)類似鋰離子電(dian)池充(chong)(chong)電(dian)器(qi)],然后快(kuai)充(chong)(chong)終止.這時充(chong)(chong)電(dian)器(qi) 需要一段(duan)Vf浮充(chong)(chong)電(dian)壓進行(xing)維護[通常用2.25V左右電(dian)壓].鉛酸[PbSO4]蓄(xu)電(dian)池允許在非確(que)定階段(duan)用此浮充(chong)(chong)電(dian)壓進行(xing)維護[見圖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(dian)池進(jin)行快充的電(dian)流要根(gen)據每攝氏度(du)0.3百分比的標(biao)準溫度(du)系數進(jin)行調低.快充時(shi)設定(ding)最(zui)大電(dian)池溫度(du) 建議在50’C左(zuo)右,但浮(fu)充一般(ban)可以(yi)超(chao)過這個溫度(du).

 

可選擇的涓流充電[適合除鋰離子電池外的其它蓄電池]

除鋰離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)外,其它蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)經常設置有一(yi)個可供選擇的(de)(de)涓(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)階(jie)段.這個階(jie)段的(de)(de)設置可以(yi)用來(lai)補償(chang)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)滿后(hou)本體的(de)(de)自放電(dian)(dian)(dian)(dian)(dian)(dian) 現象.鉛酸[PbSO4]電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)自放電(dian)(dian)(dian)(dian)(dian)(dian)率最大[每(mei)天呈數個百(bai)分(fen)點],而(er)鋰離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)最低.鋰離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)自放電(dian)(dian)(dian)(dian)(dian)(dian)率有時低到(dao)已(yi)無(wu)需(xu)涓(juan)充(chong)(chong)來(lai)維護.然而(er), 鎳(nie)(nie)鎘[NiCds]蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)卻經常,不(bu)定地需(xu)要(yao)C/16的(de)(de)涓(juan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)以(yi)進行維護.對鎳(nie)(nie)氫[NiMH]蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)而(er)言,安全(quan)的(de)(de)持續(xu)放電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)經常在C/50左(zuo)右(you),而(er)涓(juan) 流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)一(yi)般不(bu)被建議.

續放電(dian)電(dian)流(liu)經常(chang)在C/50左右,而涓(juan) 流(liu)充電(dian)一般(ban)不被建議(yi).