【鎳氫充電電池】鎳氫充電電池壽命 如何延長鎳氫充電電池壽命

鎳氫電池是(shi)鎳(nie)(nie)鎘(ge)電(dian)池(chi)的(de)后代(dai)產品，各(ge)方面性能(neng)都優于鎳(nie)(nie)鎘(ge)電(dian)池(chi)。鎳(nie)(nie)氫(qing)(qing)電(dian)池(chi)采用鎳(nie)(nie)氧(yang)化物作(zuo)(zuo)為正極，儲氫(qing)(qing)金屬作(zuo)(zuo)為負(fu)極，堿(jian)液(ye)（主要為氫(qing)(qing)氧(yang)化鉀）作(zuo)(zuo)為電(dian)解液(ye)。額定電(dian)壓(ya)為1.2V，滿充電(dian)時的(de)最大(da)電(dian)壓(ya)可(ke)達1.6V～1.8V。正常(chang)放電(dian)終(zhong)止(zhi)電(dian)壓(ya)為1.0V，實際上可(ke)使(shi)用到(dao)0.9V。重(zhong)復充電(dian)次數大(da)于500次，自放電(dian)率20％/月。

鎳氫電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)最大放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流可達3C（放(fang)電(dian)(dian)(dian)率C是指一小時放(fang)完全部容(rong)量(liang)的(de)電(dian)(dian)(dian)流值。如(ru)500mAh電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)C為500mA）。能量(liang)重量(liang)比60～80Wh／kg，能量(liang)體積比遠高于(yu)鎳鎘(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)，其(qi)單節(jie)5號電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)最大容(rong)量(liang)可達2300mAh，為鎳鎘(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)近(jin)四(si)倍多。鎳氫電(dian)(dian)(dian)池(chi)(chi)(chi)成本低(di)，無鎘(ge)污染(ran)，溫度使用(yong)范圍廣。具(ju)有良(liang)好的(de)快充電(dian)(dian)(dian)性能，無記憶效應，可以隨充隨用(yong)。故(gu)在采用(yong)通用(yong)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)設(she)備中，鎳氫電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)市場愈來愈大。

但在(zai)實用中，人(ren)們發(fa)現鎳(nie)(nie)氫電(dian)(dian)(dian)池(chi)的(de)重復(fu)充電(dian)(dian)(dian)次數反而不(bu)及鎳(nie)(nie)鎘(ge)電(dian)(dian)(dian)池(chi)多，故有鎳(nie)(nie)氫電(dian)(dian)(dian)池(chi)壽(shou)命(ming)不(bu)長(chang)之說。其實在(zai)理論上，鎳(nie)(nie)氫電(dian)(dian)(dian)池(chi)的(de)壽(shou)命(ming)比(bi)鎳(nie)(nie)鎘(ge)電(dian)(dian)(dian)池(chi)略長(chang)，但鎳(nie)(nie)氫電(dian)(dian)(dian)池(chi)過充電(dian)(dian)(dian)時，對電(dian)(dian)(dian)池(chi)的(de)不(bu)良影響比(bi)鎳(nie)(nie)鎘(ge)電(dian)(dian)(dian)池(chi)要大。

如(ru)果長期(qi)充電不當就會損傷電池。

目前市場上(shang)的(de)幾十元錢的(de)鎳鎘／鎳氫(qing)電(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)器(qi)都(dou)過于簡單，很(hen)容易造成鎳氫(qing)電(dian)(dian)(dian)池的(de)過充(chong)(chong)電(dian)(dian)(dian)。而帶充(chong)(chong)電(dian)(dian)(dian)控制芯片的(de)充(chong)(chong)電(dian)(dian)(dian)器(qi)售價高達幾百元，使用者不多。

因此，造成(cheng)鎳氫(qing)電池不能(neng)全(quan)面發揮(hui)優(you)良性能(neng)。

所以，了(le)解鎳(nie)氫(qing)電池的充電機(ji)理，正(zheng)確(que)選購和使用充電器，對延(yan)長使用壽命至關重要。

所謂正確(que)的(de)充(chong)電(dian)，就(jiu)是(shi)要使充(chong)電(dian)電(dian)池的(de)容量100％地(di)發揮出來，而且又不損傷電(dian)池。充(chong)電(dian)不正確(que)有(you)二個結果，容量不能100％地(di)發揮出來，或電(dian)池嚴重受(shou)損，在充(chong)電(dian)過程中異常發熱、破裂，甚(shen)至起火。

下圖(tu)是鎳氫充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)時(shi)的充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流和電(dian)(dian)(dian)池電(dian)(dian)(dian)壓的特(te)性關系。

圖中可見在(zai)大(da)電(dian)流充(chong)電(dian)時，電(dian)壓(ya)上升到100％后，電(dian)池電(dian)壓(ya)不升反降(jiang)。充(chong)電(dian)fC控制芯片就(jiu)能利用電(dian)池電(dian)壓(ya)從(cong)上升轉為下(xia)降(jiang)的特(te)征來結束充(chong)電(dian)，這種結束充(chong)電(dian)的判據稱(cheng)為-△V檢(jian)測(ce)。

利用(yong)-△V檢測(ce)結(jie)(jie)束(shu)充電(dian)(dian)必須(xu)恒(heng)流(liu)充電(dian)(dian)，因為(wei)(wei)電(dian)(dian)流(liu)的(de)(de)變(bian)動也(ye)會(hui)引起電(dian)(dian)池(chi)電(dian)(dian)壓的(de)(de)變(bian)動。簡(jian)單的(de)(de)充電(dian)(dian)器一般(ban)為(wei)(wei)恒(heng)壓限流(liu)充電(dian)(dian)，充電(dian)(dian)后期電(dian)(dian)流(liu)越來越小，-△V的(de)(de)檢測(ce)就變(bian)得(de)困難(nan)。所以(yi)，利用(yong)這一特性結(jie)(jie)束(shu)鎳氫電(dian)(dian)池(chi)充電(dian)(dian)時(shi)，充電(dian)(dian)電(dian)(dian)流(liu)必須(xu)保持恒(heng)定，而且必須(xu)用(yong)1C以(yi)上的(de)(de)大電(dian)(dian)流(liu)充電(dian)(dian)。

充(chong)(chong)電電池充(chong)(chong)滿電后，再繼續充(chong)(chong)電，電能變成電池的(de)熱(re)能，電池開始發(fa)熱(re)。

充(chong)電(dian)IC控制(zhi)芯片的另一個控制(zhi)就是利用溫度的上升率的增長來結束充(chong)電(dian)，稱為△T／△t檢測。一般(ban)達2℃／分鐘時，充(chong)電(dian)停(ting)止。

△T／△t檢測時(shi)(shi)，也要(yao)求(qiu)充(chong)(chong)電(dian)電(dian)流(liu)(liu)必須保(bao)持恒流(liu)(liu)。而且也是充(chong)(chong)電(dian)電(dian)流(liu)(liu)較大（0.3C以上）時(shi)(shi)，檢測較為正(zheng)確。當充(chong)(chong)電(dian)電(dian)流(liu)(liu)小(xiao)或環境溫度低、散熱(re)很好(hao)時(shi)(shi)，也會(hui)無法檢出，形(xing)成過充(chong)(chong)電(dian)。

這(zhe)兩種(zhong)正規(gui)的檢測方法都要求(qiu)大電流恒流充電。用分立元件(jian)構成，控制電路復雜(za)。用IC芯片(pian)較(jiao)方便，但溫(wen)度傳感(gan)器還必須(xu)外接。關鍵是充電器的電源部份要求(qiu)較(jiao)高(gao)(gao)，恒定電流較(jiao)大用簡單的變壓器整流己不合適，必須(xu)用開關電源。故正規(gui)的鎳氫電池充電器的售價較(jiao)高(gao)(gao)。

最為簡單(dan)的(de)控(kong)制方式是用最大(da)時(shi)間控(kong)制。按充(chong)(chong)(chong)電(dian)電(dian)流(liu)和(he)電(dian)池(chi)容量及(ji)充(chong)(chong)(chong)電(dian)效(xiao)率決定最大(da)充(chong)(chong)(chong)電(dian)時(shi)間，超(chao)過這個時(shi)間就無(wu)條件停(ting)止充(chong)(chong)(chong)電(dian)。例如，用0.1C率充(chong)(chong)(chong)電(dian)，考慮充(chong)(chong)(chong)電(dian)效(xiao)率，定時(shi)在12左右小時(shi)結束充(chong)(chong)(chong)電(dian)。但這樣充(chong)(chong)(chong)電(dian)，若開(kai)始時(shi)電(dian)池(chi)內有(you)殘留量，就會有(you)事實上(shang)的(de)過充(chong)(chong)(chong)電(dian)。

所以，定時充(chong)電(dian)(dian)電(dian)(dian)流必(bi)須小于0.3C率，大多數采(cai)用0.1C率充(chong)電(dian)(dian)。由(you)于充(chong)電(dian)(dian)電(dian)(dian)流小，過充(chong)電(dian)(dian)在電(dian)(dian)池(chi)上產生(sheng)的(de)熱量能(neng)較快地散發出去，對(dui)電(dian)(dian)池(chi)的(de)影響不大。

最(zui)大時(shi)(shi)間控制的(de)充(chong)(chong)電(dian)器安全性能較好，最(zui)適宜充(chong)(chong)足用(yong)空的(de)場合采用(yong)。對需隨用(yong)隨充(chong)(chong)的(de)電(dian)器不(bu)太合適，常會存在不(bu)嚴重(zhong)的(de)過(guo)充(chong)(chong)電(dian)。如果開始(shi)充(chong)(chong)電(dian)時(shi)(shi)能估測出電(dian)池的(de)殘留量，就可用(yong)可變時(shi)(shi)間充(chong)(chong)電(dian)方法充(chong)(chong)足。還可在必要時(shi)(shi)進行人(ren)工干(gan)預，到(dao)達估計時(shi)(shi)間或手觸(chu)電(dian)池外殼溫度明(ming)顯高于室溫時(shi)(shi)，停止充(chong)(chong)電(dian)。

好了，有了這(zhe)些基礎知識后就能(neng)正確選擇充(chong)(chong)電(dian)(dian)電(dian)(dian)池和(he)充(chong)(chong)電(dian)(dian)器(qi)了。如果你喜(xi)歡用(yong)容量較大(da)(da)的鎳(nie)氫電(dian)(dian)池，如1600mAh以(yi)上的品種，那(nei)么最好還(huan)是買一只大(da)(da)電(dian)(dian)流、帶IC控制器(qi)的充(chong)(chong)電(dian)(dian)器(qi)。這(zhe)不但可以(yi)大(da)(da)大(da)(da)縮短(duan)充(chong)(chong)電(dian)(dian)時間，還(huan)能(neng)有效地保護較為昂貴的大(da)(da)容量充(chong)(chong)電(dian)(dian)電(dian)(dian)池。

簡易型充電器使用方便、小巧易帶(dai)。但一般都是與鎳鎘電(dian)池通用的品種。為(wei)恒壓限(xian)流型(xing)充電(dian)，電(dian)路非常簡單。只在半波整流后，串一只電(dian)阻充電(dian)。

這種充(chong)(chong)電方法一開始電流(liu)(liu)較(jiao)大(da)，后(hou)來電流(liu)(liu)就被限制在0.1C的(de)小電流(liu)(liu)上，即50mA上。有(you)的(de)有(you)快充(chong)(chong)電檔，也就100mA，相當500mAh鎳(nie)鎘(ge)電池的(de)0.2C充(chong)(chong)電。好處是，用戶即使過充(chong)(chong)電，對電池的(de)影響也不(bu)大(da)。這種充(chong)(chong)電器充(chong)(chong)500mAh電池，差不(bu)多一個(ge)晚上。下(xia)班(ban)充(chong)(chong)電，上班(ban)使用正合適。

若要充(chong)1600mAh的電(dian)池(chi)就要30～40小時，實用上幾乎不(bu)可(ke)能被(bei)充(chong)足了。用戶(hu)也會象對待用手機電(dian)池(chi)充(chong)電(dian)那樣，有空(kong)就充(chong)。使這類鎳氫(qing)電(dian)池(chi)長期工作(zuo)在不(bu)飽不(bu)餓的狀態，對壽命和實際最大可(ke)用容(rong)量都(dou)有影響。

所以。選購鎳氫電(dian)(dian)(dian)池若沒有好鞍，也不必(bi)用好馬。容量適中即可(ke)，核算一(yi)下以8～1 2小時能把(ba)電(dian)(dian)(dian)池充足為宜，且充電(dian)(dian)(dian)器小于O.3C。順(shun)便提(ti)一(yi)句，大(da)容量鎳氫電(dian)(dian)(dian)池應該較(jiao)重(zhong)。如果(guo)兩節鎳氫電(dian)(dian)(dian)池重(zhong)量差(cha)不多(duo)，標稱(cheng)容量大(da)的有可(ke)能是假貨。

鎳氫(qing)電(dian)(dian)池(chi)(chi)的(de)放(fang)(fang)電(dian)(dian)也有講(jiang)究。由(you)于鎳氫(qing)電(dian)(dian)池(chi)(chi)放(fang)(fang)電(dian)(dian)終(zhong)止電(dian)(dian)壓在1.0V為正常，但在1.O～0.9伏時也還(huan)能(neng)放(fang)(fang)電(dian)(dian)。這(zhe)時就(jiu)(jiu)是過放(fang)(fang)電(dian)(dian)，對電(dian)(dian)池(chi)(chi)壽命有損。而一般設備(bei)，如收音(yin)機、隨(sui)身聽、電(dian)(dian)須刀等等都(dou)不具備(bei)1.0伏自(zi)動(dong)終(zhong)止放(fang)(fang)電(dian)(dian)的(de)電(dian)(dian)路，容易使鎳氫(qing)電(dian)(dian)池(chi)(chi)過放(fang)(fang)電(dian)(dian)。在這(zhe)類設備(bei)上(shang)使用(yong)，用(yong)到差不多感覺沒電(dian)(dian)時，就(jiu)(jiu)該充電(dian)(dian)，不能(neng)用(yong)到完全走不動(dong)再充。在數(shu)碼相(xiang)機、MP3等內部有電(dian)(dian)源管理系(xi)統的(de)設備(bei)上(shang)沒此(ci)問題。

后期放電(dian)(dian)(dian)(dian)因內(nei)阻(zu)增高，電(dian)(dian)(dian)(dian)池溫(wen)度(du)也會上升。而鎳氫電(dian)(dian)(dian)(dian)池的內(nei)阻(zu)雖比(bi)(bi)鋰離子電(dian)(dian)(dian)(dian)池低幾倍，但為鎳鎘電(dian)(dian)(dian)(dian)池內(nei)阻(zu)的2倍。故鎳氫電(dian)(dian)(dian)(dian)池后期使用(yong)發熱(re)會比(bi)(bi)鎳鎘電(dian)(dian)(dian)(dian)池大。

鎳氫電池(chi)(chi)雖然(ran)一開始認為沒有(you)記憶效應，但與后來(lai)出現(xian)的(de)(de)鋰離(li)子電池(chi)(chi)相比(bi)，仍(reng)有(you)一定的(de)(de)容量下(xia)降現(xian)象(xiang)。鎳氫電池(chi)(chi)若長期(qi)不用，就會出現(xian)休眠現(xian)象(xiang)。

容量大(da)(da)大(da)(da)降低。故對于(yu)新(xin)買(mai)來的或擱置了一段(duan)時間沒用(yong)的鎳氫電(dian)池，要先(xian)以涓流充足電(dian)量（寧過(guo)勿缺），然后以0.2C率放電(dian)到(dao)1.0V，此(ci)反(fan)復(fu)幾(ji)次(ci)，以此(ci)激(ji)活。