1.蓄電池的特點

目(mu)前常用的四種化學(xue)電(dian)(dian)池(chi)(chi)是鉛酸電(dian)(dian)池(chi)(chi)（PbSO4）、鋰離子電(dian)(dian)池(chi)(chi)（Li＋）、鎳鉻電(dian)(dian)池(chi)(chi)（NiCd）和鎳氫電(dian)(dian)池(chi)(chi)（NiMH）。由于環保問題和對電(dian)(dian)池(chi)(chi)的要求(qiu)越來(lai)越高(gao)等綜(zong)合(he)因素，推動了新電(dian)(dian)池(chi)(chi)技術的發展(zhan)。

1．1 鎳鉻(ge)電池(chi)和鎳氫(qing)電池(chi)

鎳(nie)(nie)(nie)(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)容量(liang)比鎳(nie)(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)或(huo)鋰離(li)子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)低，具有(you)低阻抗特性(xing)(xing)，對于(yu)需要(yao)短時(shi)間(jian)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)應(ying)(ying)用場合(he)很具吸引(yin)力。但(dan)(dan)鎳(nie)(nie)(nie)(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)如果未經充(chong)(chong)(chong)(chong)分放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)又(you)進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，或(huo)者(zhe)長(chang)時(shi)間(jian)處于(yu)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態，就會(hui)產生枝(zhi)狀(zhuang)(zhuang)晶體，引(yin)起“記憶效(xiao)應(ying)(ying)”，從而導(dao)致(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)內(nei)(nei)阻變(bian)大，容量(liang)變(bian)小(xiao)，縮短了電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)壽(shou)命。如果在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)前(qian)進(jin)行完全(quan)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，使(shi)每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)降到1．0V左右，就能消除引(yin)起“記憶效(xiao)應(ying)(ying)”的(de)(de)枝(zhi)狀(zhuang)(zhuang)晶體，恢復電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)性(xing)(xing)能。鎳(nie)(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)具有(you)較(jiao)高的(de)(de)容量(liang)，但(dan)(dan)其自(zi)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)(lv)也較(jiao)高，約(yue)為(wei)鎳(nie)(nie)(nie)(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)二倍。在(zai)初始(shi)階段其放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)(lv)尤高（每天放(fang)(fang)掉1％）。所(suo)以鎳(nie)(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)不(bu)(bu)宜(yi)用于(yu)需要(yao)長(chang)時(shi)間(jian)保持電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)容量(liang)的(de)(de)場合(he)。就充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式而言，兩種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)非(fei)常相似(si)，都(dou)是以恒(heng)流(liu)的(de)(de)方(fang)式進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，可采(cai)用快(kuai)速(su)(su)(su)、標準或(huo)者(zhe)涓(juan)(juan)(juan)流(liu)的(de)(de)方(fang)式進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。它們都(dou)能以超過2C（C為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)容量(liang)，單位為(wei)安培(pei)）的(de)(de)速(su)(su)(su)率(lv)(lv)進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)（但(dan)(dan)一般(ban)采(cai)用C／2速(su)(su)(su)率(lv)(lv)）。由于(yu)存在(zai)內(nei)(nei)部損耗，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)效(xiao)率(lv)(lv)一般(ban)小(xiao)于(yu)100％，所(suo)以，在(zai)采(cai)用C／2的(de)(de)速(su)(su)(su)率(lv)(lv)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，通常需要(yao)兩個多小(xiao)時(shi)才(cai)能把(ba)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)(chong)(chong)滿。充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程中的(de)(de)損耗隨著(zhu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)(su)(su)率(lv)(lv)和(he)(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)不(bu)(bu)同(tong)而不(bu)(bu)同(tong)。在(zai)恒(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)會(hui)緩慢達(da)到峰(feng)值（ΔV／Δt變(bian)為(wei)0），鎳(nie)(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)需在(zai)這個峰(feng)值點終(zhong)止快(kuai)速(su)(su)(su)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，鎳(nie)(nie)(nie)(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)須(xu)在(zai)峰(feng)值點后當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)開始(shi)下降時(shi)（ΔV／Δt變(bian)為(wei)負(fu)）即終(zhong)止快(kuai)速(su)(su)(su)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，否則會(hui)導(dao)致(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)內(nei)(nei)壓(ya)力和(he)(he)溫度(du)上(shang)升(sheng)而損壞(huai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)。當(dang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)(su)(su)率(lv)(lv)大于(yu)C／2時(shi)，則要(yao)監(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和(he)(he)溫度(du)，因為(wei)當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)快(kuai)充(chong)(chong)(chong)(chong)滿時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)溫度(du)會(hui)急劇上(shang)升(sheng)。對于(yu)鎳(nie)(nie)(nie)(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)和(he)(he)鎳(nie)(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)，還(huan)可以采(cai)用比較(jiao)簡便的(de)(de)涓(juan)(juan)(juan)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這時(shi)只會(hui)造成極小(xiao)的(de)(de)溫升(sheng)，不(bu)(bu)會(hui)損壞(huai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)，也就無需終(zhong)止涓(juan)(juan)(juan)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)者(zhe)監(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。允(yun)許(xu)的(de)(de)最(zui)大涓(juan)(juan)(juan)流(liu)隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)類型和(he)(he)環境溫度(du)的(de)(de)不(bu)(bu)同(tong)而不(bu)(bu)同(tong)，典型條件下C／15較(jiao)為(wei)安全(quan)。

1．2 鋰離子電池

過(guo)(guo)去(qu)幾年中，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)技術領域(yu)最(zui)突出的(de)(de)創新就(jiu)是鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)。相(xiang)對于鎳基電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)而言，鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)具有(you)更高的(de)(de)容量(liang)(liang)。從(cong)容量(liang)(liang)／體(ti)積(ji)比(bi)來衡量(liang)(liang)，鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)比(bi)鎳氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)高出10％～30％，從(cong)容量(liang)(liang)／質(zhi)量(liang)(liang)比(bi)來看，鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)比(bi)鎳氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)高出近兩倍(bei)。但鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)對于過(guo)(guo)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和(he)欠充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)很敏感。要達到(dao)最(zui)大(da)(da)容量(liang)(liang)就(jiu)必須(xu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)到(dao)最(zui)高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，而過(guo)(guo)高的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和(he)過(guo)(guo)大(da)(da)的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)又會造成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)永久性(xing)損壞。如果(guo)多次放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)至過(guo)(guo)低(di)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)則會造成容量(liang)(liang)損失，所以(yi)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和(he)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)都須(xu)限制(zhi)其電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，以(yi)保護電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)不(bu)受損壞。鋰離(li)(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式不(bu)同于鎳基材料(liao)的(de)(de)化學(xue)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)需用(yong)一個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)―電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)源來進(jin)行充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。為(wei)了獲得最(zui)大(da)(da)的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)而又不(bu)損壞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，須(xu)使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保持在1％的(de)(de)精度內。快速充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)開始時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)比(bi)較(jiao)低(di)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)即(ji)為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)極限。隨著充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)進(jin)行，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)緩慢(man)上升，最(zui)終當每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)達到(dao)浮(fu)空(kong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya) 4．2V時(shi)，此時(shi)即(ji)可(ke)終止充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

2　總體設計

2．1 充電器(qi)芯片(pian)MAX846A

MAX846A是一種16腳QSOP封裝的通用型充電控制芯片，可以單獨構成鋰離子電池充電器，也可以在單片機的控制下對鋰離子電池和鎳基電池進(jin)行(xing)充電(dian)(dian)(dian)。圖1為(wei)(wei)(wei)(wei)(wei)其QSOP封裝的(de)管腳(jiao)(jiao)(jiao)圖。圖中，1腳(jiao)(jiao)(jiao)DCIN和(he)(he)(he)4腳(jiao)(jiao)(jiao)GND及15腳(jiao)(jiao)(jiao)PGND分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)(wei)電(dian)(dian)(dian)源和(he)(he)(he)地(di)端(duan)(duan)(duan)。2腳(jiao)(jiao)(jiao)VL端(duan)(duan)(duan)可提供3．3V，1％的(de)電(dian)(dian)(dian)壓(ya)基準。3腳(jiao)(jiao)(jiao)CCI和(he)(he)(he)5腳(jiao)(jiao)(jiao)CCV分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)(wei)電(dian)(dian)(dian)流(liu)和(he)(he)(he)電(dian)(dian)(dian)壓(ya)調節(jie)回路(lu)(lu)補償端(duan)(duan)(duan)。7腳(jiao)(jiao)(jiao)ISET和(he)(he)(he)6腳(jiao)(jiao)(jiao)VSET分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)(wei)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)和(he)(he)(he)電(dian)(dian)(dian)壓(ya)回路(lu)(lu)設定(ding)端(duan)(duan)(duan)。8腳(jiao)(jiao)(jiao)OFFV為(wei)(wei)(wei)(wei)(wei)電(dian)(dian)(dian)壓(ya)調節(jie)回路(lu)(lu)控(kong)制端(duan)(duan)(duan)，對于鎳基電(dian)(dian)(dian)池(chi)置為(wei)(wei)(wei)(wei)(wei)高電(dian)(dian)(dian)平。當VL端(duan)(duan)(duan)電(dian)(dian)(dian)壓(ya)低(di)于3V時，9腳(jiao)(jiao)(jiao)PWROK輸出低(di)電(dian)(dian)(dian)平，可給MCU提供復(fu)位信(xin)號(hao)。10腳(jiao)(jiao)(jiao)CELL2為(wei)(wei)(wei)(wei)(wei)鋰(li)離(li)子電(dian)(dian)(dian)池(chi)選(xuan)擇端(duan)(duan)(duan)，低(di)電(dian)(dian)(dian)平時為(wei)(wei)(wei)(wei)(wei)一節(jie)，高電(dian)(dian)(dian)平時為(wei)(wei)(wei)(wei)(wei)兩(liang)節(jie)。11腳(jiao)(jiao)(jiao)ON為(wei)(wei)(wei)(wei)(wei)充電(dian)(dian)(dian)控(kong)制端(duan)(duan)(duan)，低(di)電(dian)(dian)(dian)平時停止(zhi)充電(dian)(dian)(dian)。12腳(jiao)(jiao)(jiao)BATT端(duan)(duan)(duan)接電(dian)(dian)(dian)池(chi)正極。13腳(jiao)(jiao)(jiao)CS＋和(he)(he)(he)14腳(jiao)(jiao)(jiao)CS－為(wei)(wei)(wei)(wei)(wei)內部電(dian)(dian)(dian)流(liu)檢(jian)測放(fang)大器輸入端(duan)(duan)(duan)。16腳(jiao)(jiao)(jiao)DRV為(wei)(wei)(wei)(wei)(wei)外部調節(jie)晶體管驅動端(duan)(duan)(duan)。

2．2 硬件設計

充電器硬件結構圖如圖2所示。整個系統以MCU為核心構成，包括電源電路、調節電路、充電與放電電路、鍵盤與顯示電路及報警電路等環節。
 

MCU選用(yong)AT89C51，片內帶(dai)4K的(de)(de)(de)EEPROM，這樣就無需擴展程序存(cun)儲器，簡化了電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)設(she)計。電(dian)(dian)(dian)(dian)(dian)(dian)源回路(lu)中，220V的(de)(de)(de)交流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)經(jing)變壓(ya)(ya)器降為(wei) 12V，經(jing)過(guo)整流(liu)(liu)濾(lv)波變為(wei)14V左(zuo)右，作(zuo)(zuo)為(wei)MAX846A的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)源，另外經(jing)7805穩(wen)壓(ya)(ya)后作(zuo)(zuo)為(wei)其(qi)他電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)單(dan)元的(de)(de)(de)工作(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)(dian)源。調節電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)主(zhu)要由A／D和(he)(he)D／A構成，用(yong)于檢測電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)(he)溫度及(ji)設(she)置電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)浮(fu)空(kong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)(he)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)以(yi)MAX846A為(wei)中心，完(wan)成充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程的(de)(de)(de)啟停及(ji)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式的(de)(de)(de)選擇由單(dan)片機對MAX846A進(jin)行控制來實現(xian)。放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)用(yong)以(yi)消除鎳(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)“記憶效應”。報警電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)在系統工作(zuo)(zuo)時給出必要的(de)(de)(de)聲(sheng)音提(ti)示。鍵(jian)盤和(he)(he)顯(xian)示電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)用(yong)于設(she)置和(he)(he)顯(xian)示相關的(de)(de)(de)參數。

2．3 充電器的功能設計
　　系統工作時通過鍵盤選擇電池類型和充電方式，并由一位數碼管顯示。具體方式如下所示：
    （1）鎳鉻電池全電流快速充電方式
    （2）鎳鉻電池標準充電方式
    （3）鎳氫電池全電流快速充電方式
    （4）鎳氫電池標準充電方式
    （5）鋰離子電池快速充電方式
    （6）鋰離(li)子電池(chi)標準(zhun)充電方(fang)式

系統啟動時先進行初始化，隨后檢查電池是否開路。如開路則LED顯示0并蜂鳴提示，如正常則按照設置的充電方式進行充電。在對鎳鉻電池充電時，首先檢測電池是否已充分放電，如單節電池電壓在1．0V以上，則先進行完全放電以消除其“記憶效應”。對于鎳基電池，無論采用哪一種充電方式，在充電結束后自動進入涓流充電方式，以補償電池的自放電。鋰離子電池的自放電率最低，所以無需涓流充電。在快速充電時，鎳鉻電池采用負斜率終止充電（ΔV／Δt小于0），鎳氫電池采用(yong)零斜(xie)率(lv)終止(zhi)充電（ΔV／Δt等于(yu)0），鋰離(li)子(zi)電池(chi)(chi)采用(yong)頂端截止(zhi)。另外，在快速充電時(shi)，如電池(chi)(chi)電壓或者(zhe)溫度(du)超限以及充電時(shi)間超過三小時(shi)，系統都將停止(zhi)充電并蜂鳴(ming)(ming)提示(shi)。充電結束時(shi)數碼管顯(xian)示(shi)P并蜂鳴(ming)(ming)提示(shi)。出于(yu)對電池(chi)(chi)壽(shou)命的(de)考慮，在多次快充后，建(jian)議采用(yong)標(biao)準方(fang)式充電一次。

2．4 軟件設計

系統的軟件(jian)設(she)計采用模(mo)(mo)(mo)塊(kuai)式(shi)結(jie)構，主要(yao)由初始(shi)化程(cheng)序(xu)、充電(dian)方(fang)式(shi)設(she)置模(mo)(mo)(mo)塊(kuai)、預處理模(mo)(mo)(mo)塊(kuai)、A／D轉換模(mo)(mo)(mo)塊(kuai)、D／A轉換模(mo)(mo)(mo)塊(kuai)、定時模(mo)(mo)(mo)塊(kuai)和(he)顯示(shi)模(mo)(mo)(mo)塊(kuai)等部分組成。其中(zhong)，充電(dian)方(fang)式(shi)設(she)置模(mo)(mo)(mo)塊(kuai)用于(yu)設(she)置電(dian)池(chi)類型和(he)充電(dian)方(fang)式(shi)；A／D轉換模(mo)(mo)(mo)塊(kuai)用于(yu)檢(jian)測(ce)電(dian)池(chi)的電(dian)壓和(he)溫度，以確定是否終止(zhi)充電(dian)過程(cheng)；D／A轉換模(mo)(mo)(mo)塊(kuai)用于(yu)設(she)置充電(dian)電(dian)流(liu)和(he)電(dian)壓；定時模(mo)(mo)(mo)塊(kuai)用于(yu)確定零斜(xie)率(lv)或(huo)負斜(xie)率(lv)檢(jian)測(ce)的頻度以及快充的時間(jian)監測(ce)，斜(xie)率(lv)檢(jian)測(ce)為每分鐘一次(ci)，快充的時間(jian)限為三(san)小時。系統程(cheng)序(xu)的流(liu)程(cheng)圖(tu)如圖(tu)3所示(shi)。

3　結束語

采用單片機和充電集成電路進行充電器設計，不但能(neng)(neng)(neng)夠實(shi)現(xian)對(dui)一般的(de)蓄電(dian)池(chi)進行(xing)充(chong)電(dian)，而且還能(neng)(neng)(neng)夠實(shi)現(xian)相應的(de)過(guo)壓和溫度保護，從而可(ke)以充(chong)分發(fa)揮蓄電(dian)池(chi)的(de)性(xing)能(neng)(neng)(neng)，延長電(dian)池(chi)的(de)使用壽命(ming)，并(bing)避免簡(jian)易充(chong)電(dian)器在充(chong)電(dian)時可(ke)能(neng)(neng)(neng)對(dui)電(dian)池(chi)造成損害的(de)情況發(fa)生，具有一定的(de)智能(neng)(neng)(neng)功能(neng)(neng)(neng)，符合目前(qian)的(de)環(huan)境(jing)保護潮流。