1.蓄電池的特點

目前常用的四種化學電(dian)(dian)池(chi)是(shi)鉛酸電(dian)(dian)池(chi)（PbSO4）、鋰離子電(dian)(dian)池(chi)（Li＋）、鎳鉻電(dian)(dian)池(chi)（NiCd）和鎳氫(qing)電(dian)(dian)池(chi)（NiMH）。由于環保問題和對電(dian)(dian)池(chi)的要求越來越高等(deng)綜合因素(su)，推動了新電(dian)(dian)池(chi)技術(shu)的發展。

1．1 鎳(nie)鉻電池和(he)鎳(nie)氫電池

鎳(nie)(nie)(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)容量(liang)(liang)比(bi)鎳(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)或(huo)鋰離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)低(di)，具(ju)(ju)有低(di)阻抗特(te)性(xing)，對(dui)于需(xu)要(yao)(yao)短(duan)時(shi)(shi)間(jian)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)應(ying)用(yong)場(chang)合(he)很具(ju)(ju)吸引(yin)力。但鎳(nie)(nie)(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)如(ru)果(guo)未經(jing)充(chong)(chong)(chong)(chong)分(fen)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)又進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，或(huo)者(zhe)長(chang)時(shi)(shi)間(jian)處于小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態，就(jiu)(jiu)會(hui)(hui)產生枝(zhi)狀晶體(ti)，引(yin)起“記憶效應(ying)”，從而(er)導致電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)內阻變大，容量(liang)(liang)變小，縮(suo)短(duan)了電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)壽命。如(ru)果(guo)在(zai)(zai)(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)前(qian)進(jin)行完全放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，使每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓降到1．0V左右(you)，就(jiu)(jiu)能(neng)消除引(yin)起“記憶效應(ying)”的(de)(de)(de)(de)枝(zhi)狀晶體(ti)，恢復電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)性(xing)能(neng)。鎳(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)具(ju)(ju)有較高的(de)(de)(de)(de)容量(liang)(liang)，但其(qi)自放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)(lv)也(ye)較高，約為(wei)鎳(nie)(nie)(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)二(er)倍。在(zai)(zai)(zai)初始(shi)階(jie)段(duan)其(qi)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)率(lv)(lv)尤高（每天(tian)放(fang)(fang)(fang)掉1％）。所(suo)以(yi)(yi)鎳(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)不(bu)宜用(yong)于需(xu)要(yao)(yao)長(chang)時(shi)(shi)間(jian)保持電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)容量(liang)(liang)的(de)(de)(de)(de)場(chang)合(he)。就(jiu)(jiu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式而(er)言(yan)，兩種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)非(fei)常(chang)相似，都是以(yi)(yi)恒流的(de)(de)(de)(de)方式進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，可采用(yong)快速(su)、標準(zhun)或(huo)者(zhe)涓(juan)流的(de)(de)(de)(de)方式進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。它們都能(neng)以(yi)(yi)超過2C（C為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)容量(liang)(liang)，單位為(wei)安培）的(de)(de)(de)(de)速(su)率(lv)(lv)進(jin)行充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)（但一般采用(yong)C／2速(su)率(lv)(lv)）。由于存(cun)在(zai)(zai)(zai)內部損耗(hao)，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)效率(lv)(lv)一般小于100％，所(suo)以(yi)(yi)，在(zai)(zai)(zai)采用(yong)C／2的(de)(de)(de)(de)速(su)率(lv)(lv)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)，通(tong)常(chang)需(xu)要(yao)(yao)兩個多小時(shi)(shi)才(cai)能(neng)把電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)充(chong)(chong)(chong)(chong)滿(man)。充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程中的(de)(de)(de)(de)損耗(hao)隨著(zhu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)率(lv)(lv)和(he)(he)(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)不(bu)同而(er)不(bu)同。在(zai)(zai)(zai)恒流充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓會(hui)(hui)緩(huan)慢達到峰(feng)值（ΔV／Δt變為(wei)0），鎳(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)需(xu)在(zai)(zai)(zai)這個峰(feng)值點終止(zhi)快速(su)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，鎳(nie)(nie)(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)須在(zai)(zai)(zai)峰(feng)值點后當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓開始(shi)下(xia)降時(shi)(shi)（ΔV／Δt變為(wei)負）即終止(zhi)快速(su)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，否則(ze)會(hui)(hui)導致電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)內壓力和(he)(he)(he)溫(wen)度(du)(du)上(shang)升(sheng)而(er)損壞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)。當充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)率(lv)(lv)大于C／2時(shi)(shi)，則(ze)要(yao)(yao)監測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)(he)(he)溫(wen)度(du)(du)，因為(wei)當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)快充(chong)(chong)(chong)(chong)滿(man)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)溫(wen)度(du)(du)會(hui)(hui)急(ji)劇上(shang)升(sheng)。對(dui)于鎳(nie)(nie)(nie)鉻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)和(he)(he)(he)鎳(nie)(nie)(nie)氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)，還可以(yi)(yi)采用(yong)比(bi)較簡(jian)便的(de)(de)(de)(de)涓(juan)流充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這時(shi)(shi)只會(hui)(hui)造成極小的(de)(de)(de)(de)溫(wen)升(sheng)，不(bu)會(hui)(hui)損壞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)，也(ye)就(jiu)(jiu)無(wu)需(xu)終止(zhi)涓(juan)流充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)者(zhe)監測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓。允許的(de)(de)(de)(de)最大涓(juan)流隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)類型和(he)(he)(he)環境溫(wen)度(du)(du)的(de)(de)(de)(de)不(bu)同而(er)不(bu)同，典(dian)型條件下(xia)C／15較為(wei)安全。

1．2 鋰離子電池

過(guo)(guo)去(qu)幾年(nian)中，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)技術領域最突出的(de)(de)(de)(de)創新就是鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)。相對于鎳基(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)而(er)言，鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)具(ju)有更高(gao)的(de)(de)(de)(de)容量(liang)(liang)。從容量(liang)(liang)／體積比(bi)來(lai)衡(heng)量(liang)(liang)，鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)比(bi)鎳氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)高(gao)出10％～30％，從容量(liang)(liang)／質量(liang)(liang)比(bi)來(lai)看(kan)，鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)比(bi)鎳氫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)高(gao)出近(jin)兩倍。但(dan)鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)對于過(guo)(guo)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和欠(qian)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)很(hen)敏感(gan)。要達到(dao)最大(da)容量(liang)(liang)就必須(xu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)到(dao)最高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，而(er)過(guo)(guo)高(gao)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和過(guo)(guo)大(da)的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或放(fang)電(dian)(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)(dian)流(liu)又(you)(you)會造(zao)成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)永久(jiu)性損壞(huai)(huai)(huai)。如果多次放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)至過(guo)(guo)低的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)則會造(zao)成容量(liang)(liang)損失，所以，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)都(dou)須(xu)限(xian)制其(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，以保護電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)不受(shou)損壞(huai)(huai)(huai)。鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式不同(tong)于鎳基(ji)(ji)材料的(de)(de)(de)(de)化(hua)學電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)需(xu)用一個電(dian)(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)(dian)流(liu)源(yuan)來(lai)進行(xing)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。為了(le)獲得最大(da)的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)而(er)又(you)(you)不損壞(huai)(huai)(huai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)，須(xu)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保持(chi)在1％的(de)(de)(de)(de)精(jing)度內。快速充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)開始(shi)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)比(bi)較低，充(chong)(chong)(chong)(chong)電(dian)(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)(dian)流(liu)即為電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)極限(xian)。隨著充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)進行(xing)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)緩慢(man)上升，最終當每節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)達到(dao)浮(fu)空電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya) 4．2V時(shi)(shi)，此時(shi)(shi)即可終止(zhi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

2　總體設計

2．1 充(chong)電器芯片(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行充(chong)電(dian)(dian)(dian)(dian)。圖1為(wei)(wei)(wei)(wei)其(qi)QSOP封(feng)裝的管腳(jiao)(jiao)(jiao)(jiao)(jiao)圖。圖中(zhong)，1腳(jiao)(jiao)(jiao)(jiao)(jiao)DCIN和(he)(he)4腳(jiao)(jiao)(jiao)(jiao)(jiao)GND及15腳(jiao)(jiao)(jiao)(jiao)(jiao)PGND分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)電(dian)(dian)(dian)(dian)源和(he)(he)地端。2腳(jiao)(jiao)(jiao)(jiao)(jiao)VL端可提供3．3V，1％的電(dian)(dian)(dian)(dian)壓(ya)基準。3腳(jiao)(jiao)(jiao)(jiao)(jiao)CCI和(he)(he)5腳(jiao)(jiao)(jiao)(jiao)(jiao)CCV分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)電(dian)(dian)(dian)(dian)流(liu)和(he)(he)電(dian)(dian)(dian)(dian)壓(ya)調節(jie)回路(lu)補償(chang)端。7腳(jiao)(jiao)(jiao)(jiao)(jiao)ISET和(he)(he)6腳(jiao)(jiao)(jiao)(jiao)(jiao)VSET分(fen)別(bie)(bie)為(wei)(wei)(wei)(wei)充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)和(he)(he)電(dian)(dian)(dian)(dian)壓(ya)回路(lu)設定端。8腳(jiao)(jiao)(jiao)(jiao)(jiao)OFFV為(wei)(wei)(wei)(wei)電(dian)(dian)(dian)(dian)壓(ya)調節(jie)回路(lu)控制端，對于(yu)鎳基電(dian)(dian)(dian)(dian)池置為(wei)(wei)(wei)(wei)高電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)。當VL端電(dian)(dian)(dian)(dian)壓(ya)低于(yu)3V時，9腳(jiao)(jiao)(jiao)(jiao)(jiao)PWROK輸出低電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)，可給MCU提供復位信號。10腳(jiao)(jiao)(jiao)(jiao)(jiao)CELL2為(wei)(wei)(wei)(wei)鋰(li)離(li)子電(dian)(dian)(dian)(dian)池選(xuan)擇端，低電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)時為(wei)(wei)(wei)(wei)一(yi)節(jie)，高電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)時為(wei)(wei)(wei)(wei)兩節(jie)。11腳(jiao)(jiao)(jiao)(jiao)(jiao)ON為(wei)(wei)(wei)(wei)充(chong)電(dian)(dian)(dian)(dian)控制端，低電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)時停止充(chong)電(dian)(dian)(dian)(dian)。12腳(jiao)(jiao)(jiao)(jiao)(jiao)BATT端接電(dian)(dian)(dian)(dian)池正(zheng)極。13腳(jiao)(jiao)(jiao)(jiao)(jiao)CS＋和(he)(he)14腳(jiao)(jiao)(jiao)(jiao)(jiao)CS－為(wei)(wei)(wei)(wei)內(nei)部(bu)電(dian)(dian)(dian)(dian)流(liu)檢(jian)測放大器輸入(ru)端。16腳(jiao)(jiao)(jiao)(jiao)(jiao)DRV為(wei)(wei)(wei)(wei)外部(bu)調節(jie)晶(jing)體管驅動端。

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4K的(de)(de)(de)EEPROM，這樣就無需擴展(zhan)程(cheng)序存儲器(qi)，簡化了電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)設(she)(she)計。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)回路(lu)中(zhong)，220V的(de)(de)(de)交流電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)經變壓器(qi)降為 12V，經過整流濾波變為14V左(zuo)右，作(zuo)為MAX846A的(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，另外經7805穩(wen)壓后作(zuo)為其他電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)單元的(de)(de)(de)工作(zuo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)。調(diao)節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)主要(yao)由A／D和(he)(he)(he)D／A構成，用(yong)于(yu)檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)(he)(he)溫(wen)度及設(she)(she)置電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)浮空(kong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)(he)(he)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)以(yi)MAX846A為中(zhong)心，完成充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)的(de)(de)(de)啟停及充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)的(de)(de)(de)選擇(ze)由單片機對MAX846A進(jin)行(xing)控(kong)制來實現。放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)用(yong)以(yi)消除鎳(nie)鉻(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)“記(ji)憶效(xiao)應”。報警電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)在系統(tong)工作(zuo)時給出必要(yao)的(de)(de)(de)聲音提示(shi)(shi)。鍵盤和(he)(he)(he)顯示(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)用(yong)于(yu)設(she)(she)置和(he)(he)(he)顯示(shi)(shi)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)子電池標準充電方(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(cai)用零斜率終止(zhi)充電(dian)(dian)（ΔV／Δt等于0），鋰離子電(dian)(dian)池采(cai)用頂端(duan)截(jie)止(zhi)。另外，在(zai)快速充電(dian)(dian)時(shi)，如電(dian)(dian)池電(dian)(dian)壓(ya)或者溫度超限以及充電(dian)(dian)時(shi)間超過三小時(shi)，系統都將停止(zhi)充電(dian)(dian)并蜂(feng)鳴提示(shi)。充電(dian)(dian)結束(shu)時(shi)數碼管顯示(shi)P并蜂(feng)鳴提示(shi)。出于對(dui)電(dian)(dian)池壽命的考慮，在(zai)多次快充后，建議采(cai)用標(biao)準方式充電(dian)(dian)一(yi)次。

2．4 軟件設計

系(xi)統(tong)的軟(ruan)件設(she)(she)計采用(yong)模(mo)(mo)塊(kuai)式結構，主要(yao)由初始化程(cheng)序、充電(dian)(dian)方式設(she)(she)置(zhi)模(mo)(mo)塊(kuai)、預處(chu)理模(mo)(mo)塊(kuai)、A／D轉(zhuan)換模(mo)(mo)塊(kuai)、D／A轉(zhuan)換模(mo)(mo)塊(kuai)、定(ding)(ding)時(shi)(shi)模(mo)(mo)塊(kuai)和顯示(shi)(shi)模(mo)(mo)塊(kuai)等(deng)部分組(zu)成。其(qi)中，充電(dian)(dian)方式設(she)(she)置(zhi)模(mo)(mo)塊(kuai)用(yong)于設(she)(she)置(zhi)電(dian)(dian)池(chi)類(lei)型(xing)和充電(dian)(dian)方式；A／D轉(zhuan)換模(mo)(mo)塊(kuai)用(yong)于檢(jian)測(ce)(ce)電(dian)(dian)池(chi)的電(dian)(dian)壓和溫度(du)，以確定(ding)(ding)是否終止充電(dian)(dian)過程(cheng)；D／A轉(zhuan)換模(mo)(mo)塊(kuai)用(yong)于設(she)(she)置(zhi)充電(dian)(dian)電(dian)(dian)流和電(dian)(dian)壓；定(ding)(ding)時(shi)(shi)模(mo)(mo)塊(kuai)用(yong)于確定(ding)(ding)零(ling)斜(xie)率或負(fu)斜(xie)率檢(jian)測(ce)(ce)的頻度(du)以及快充的時(shi)(shi)間監測(ce)(ce)，斜(xie)率檢(jian)測(ce)(ce)為(wei)每分鐘一次，快充的時(shi)(shi)間限為(wei)三小時(shi)(shi)。系(xi)統(tong)程(cheng)序的流程(cheng)圖(tu)如(ru)圖(tu)3所示(shi)(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(bu)但能(neng)(neng)(neng)夠實(shi)現(xian)對一般的(de)(de)蓄電(dian)池(chi)(chi)進行(xing)充電(dian)，而且還能(neng)(neng)(neng)夠實(shi)現(xian)相應(ying)的(de)(de)過(guo)壓和溫(wen)度保(bao)護，從而可(ke)以(yi)充分發揮(hui)蓄電(dian)池(chi)(chi)的(de)(de)性能(neng)(neng)(neng)，延長電(dian)池(chi)(chi)的(de)(de)使(shi)用壽命，并避免(mian)簡(jian)易充電(dian)器在充電(dian)時可(ke)能(neng)(neng)(neng)對電(dian)池(chi)(chi)造成損害的(de)(de)情況(kuang)發生，具有一定的(de)(de)智能(neng)(neng)(neng)功能(neng)(neng)(neng)，符合目前的(de)(de)環境(jing)保(bao)護潮流。