鋰電池的充(chong)電方法對于不同數(shu)量的電芯(xin)、電芯(xin)配置以及電源類型還是不同的。目前鋰電池充(chong)電主要有：線性,Buck(降(jiang)壓(ya)(ya))開(kai)關和 SEPIC(升壓(ya)(ya)與(yu)降(jiang)壓(ya)(ya)開(kai)關)這個(ge)三個(ge)方法，具體操作如下：

1、鋰電(dian)池的(de)線性充電(dian)方法

當充電(dian)(dian)器(qi)輸(shu)入電(dian)(dian)壓(ya)大于全充滿(man)電(dian)(dian)芯加上充足浄空之后(hou)的開路電(dian)(dian)壓(ya)時,最好用線(xian)性方(fang)案,特(te)別是1.0C快(kuai)速充電(dian)(dian)電(dian)(dian)流不比1A大太多時。

例如(ru):MP3播放器(qi)(qi)通常(chang)只有(you)一個(ge)鋰電(dian)(dian)(dian)池電(dian)(dian)(dian)芯,容量從700到1500mAh不等,滿充(chong)(chong)(chong)(chong)開路(lu)電(dian)(dian)(dian)壓是(shi)(shi)(shi)4.2V。MP3播放機(ji)的(de)電(dian)(dian)(dian)源通常(chang)是(shi)(shi)(shi)AC/DC適(shi)配(pei)器(qi)(qi)或者是(shi)(shi)(shi)USB接口,其(qi)輸出(chu)是(shi)(shi)(shi)規則的(de)5V;這時,線(xian)性方(fang)案的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)就是(shi)(shi)(shi)最簡單(dan)、最有(you)效率的(de)方(fang)案。線(xian)性方(fang)案的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)應(ying)用(yong)例舉(ju)-雙輸入(ru)Li+充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)及智能電(dian)(dian)(dian)源選擇器(qi)(qi)是(shi)(shi)(shi)雙輸入(ru)USB/AC適(shi)配(pei)器(qi)(qi)線(xian)性充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi),內(nei)置Smart Power Selector,用(yong)于由可充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)單(dan)節Li+電(dian)(dian)(dian)池供電(dian)(dian)(dian)的(de)便(bian)攜式設備。該(gai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)集成(cheng)了電(dian)(dian)(dian)池和外部電(dian)(dian)(dian)源充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)和切換(huan)負載(zai)所需(xu)的(de)全部功率開關,因此(ci)無需(xu)外部MOSFET:MAX8677A理想用(yong)于便(bian)

攜式設備,例如智(zhi)能手機、PDA、便(bian)攜式多媒體播(bo)放器、GPS導(dao)航設備、數碼(ma)(ma)相機、以及數碼(ma)(ma)攝像機MAX8677A可以工作于獨立的(de)(de)(de)USB和AC適配(pei)器電(dian)(dian)源輸入(ru)下(xia)或(huo)(huo)兩個輸入(ru)中(zhong)的(de)(de)(de)任意一個輸入(ru)下(xia):當連(lian)接(jie)(jie)外部(bu)電(dian)(dian)源時,智(zhi)能電(dian)(dian)源選(xuan)擇(ze)器允(yun)許系統(tong)不連(lian)接(jie)(jie)電(dian)(dian)池或(huo)(huo)可以與深度放電(dian)(dian)電(dian)(dian)池連(lian)接(jie)(jie)。智(zhi)能電(dian)(dian)源選(xuan)擇(ze)器自動將電(dian)(dian)池切換到系統(tong)負載(zai),使用系統(tong)未利(li)(li)用的(de)(de)(de)輸入(ru)電(dian)(dian)源部(bu)分為電(dian)(dian)池充(chong)電(dian)(dian),充(chong)分利(li)(li)用有限(xian)的(de)(de)(de)USB和適配(pei)器輸入(ru)電(dian)(dian)源。所有需要(yao)的(de)(de)(de)電(dian)(dian)流檢測

電(dian)(dian)(dian)路,包(bao)(bao)括集成的(de)(de)(de)功率開關(guan),均(jun)集成于片上。DC輸入電(dian)(dian)(dian)流(liu)限(xian)最高可調(diao)節(jie)(jie)至(zhi)2A,而DC和(he)USB輸入均(jun)可支持(chi)100mA、500mA和(he)USB掛起模(mo)式。充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)可調(diao)節(jie)(jie)至(zhi)高達1.5A,從而支持(chi)寬范圍(wei)的(de)(de)(de)電(dian)(dian)(dian)池容(rong)性。MAX8677A的(de)(de)(de)其他特性包(bao)(bao)括熱調(diao)節(jie)(jie)、過壓保護、充電(dian)(dian)(dian)狀態(tai)和(he)故障翰出、電(dian)(dian)(dian)源好監視(shi)、電(dian)(dian)(dian)池熱敏(min)電(dian)(dian)(dian)阻監視(shi)、以(yi)及充電(dian)(dian)(dian)定時器。MAX8677A采用節(jie)(jie)省空間的(de)(de)(de)、熱增(zeng)強(qiang)型、4mmx4mm、24引腳(jiao)的(de)(de)(de)TQFN封裝,規定工作于擴(kuo)展級溫度范圍(wei)(-40~+85℃)

2、鋰電池的Buck(降壓)開關充電方法

當(dang)1.0C充(chong)(chong)電(dian)(dian)(dian)的(de)電(dian)(dian)(dian)流大于1A,或者(zhe)輸入電(dian)(dian)(dian)壓(ya)(ya)(ya)比電(dian)(dian)(dian)芯的(de)全充(chong)(chong)滿開路電(dian)(dian)(dian)壓(ya)(ya)(ya)高很多時,Buck或者(zhe)降壓(ya)(ya)(ya)方案(an)就(jiu)是(shi)一個更好的(de)選擇(ze)。比如,在(zai)基于硬(ying)盤的(de)PMP中,通常使用單芯鋰(li)離子電(dian)(dian)(dian)池(chi),全充(chong)(chong)滿開路電(dian)(dian)(dian)壓(ya)(ya)(ya)是(shi)4.2V,容量從1200到2400mAh不等。而現(xian)在(zai)PMP通常是(shi)用汽車套件來充(chong)(chong)電(dian)(dian)(dian),它的(de)輸出電(dian)(dian)(dian)壓(ya)(ya)(ya)在(zai)9V到16V之間。在(zai)輸入電(dian)(dian)(dian)壓(ya)(ya)(ya)和鋰(li)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)之間比較高的(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)差(cha)(最小4.8V)會讓線性方案(an)降低(di)效(xiao)率(lv)。這(zhe)種(zhong)低(di)效(xiao)率(lv),加(jia)上大于1.2A的(de)1C快速充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流,會產生嚴重的(de)散(san)熱問題。為避免(mian)這(zhe)種(zhong)情況(kuang),就(jiu)要采用Buck方案(an)

3、鋰電(dian)池的SEPIC(升(sheng)壓與降壓)開關充(chong)電(dian)方法

在(zai)某些使用3個甚至4個鋰離(li)子/聚合物(wu)電(dian)(dian)(dian)(dian)芯串聯(lian)的設備中，充電(dian)(dian)(dian)(dian)器(qi)的輸(shu)(shu)入電(dian)(dian)(dian)(dian)壓(ya)就不總是大于電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓(ya)。比如，筆記本電(dian)(dian)(dian)(dian)腦使用3芯鋰離(li)子電(dian)(dian)(dian)(dian)池(chi)組，滿充開路電(dian)(dian)(dian)(dian)壓(ya)是12.6V(4.2V×3)，容量從1800mAh到3600mAh。輸(shu)(shu)入電(dian)(dian)(dian)(dian)源要(yao)(yao)么是輸(shu)(shu)出電(dian)(dian)(dian)(dian)壓(ya)16V的AC/DC適配器(qi)，要(yao)(yao)么是汽(qi)車套件，輸(shu)(shu)出電(dian)(dian)(dian)(dian)壓(ya)在(zai)9V到16V之間(jian)。很顯(xian)然地，線(xian)性和Buck方案都不能為(wei)這組電(dian)(dian)(dian)(dian)池(chi)組充電(dian)(dian)(dian)(dian)。這就要(yao)(yao)用上(shang)SEPIC方案，它能在(zai)輸(shu)(shu)出電(dian)(dian)(dian)(dian)壓(ya)高于電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓(ya)時(shi)工作，也(ye)能在(zai)輸(shu)(shu)出電(dian)(dian)(dian)(dian)壓(ya)低于電(dian)(dian)(dian)(dian)池(chi)時(shi)工作。