看(kan)(kan)到消息說手(shou)機用(yong)USB充(chong)電(dian)(dian)，充(chong)不滿，而且(qie)電(dian)(dian)量掉(diao)得快，搞(gao)得不好會(hui)漏電(dian)(dian)。用(yong)直充(chong)就沒有這(zhe)(zhe)個(ge)問(wen)題(ti)，真的(de)是(shi)這(zhe)(zhe)樣嗎？ 聽聽果殼(ke)網科學控(kong)的(de)分析吧。“科學白癡”們可(ke)以直接跳(tiao)到最后一段，看(kan)(kan)結(jie)論(lun)。

鋰電池的充電方式

   鋰電池的(de)(de)充(chong)電(dian)(dian)(dian)(dian)方式(shi)是(shi)(shi)限壓(ya)(ya)恒(heng)流(liu)(liu)，都是(shi)(shi)由IC芯(xin)片控制的(de)(de)，典(dian)型的(de)(de)充(chong)電(dian)(dian)(dian)(dian)方式(shi)是(shi)(shi)：先(xian)檢(jian)測待充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)池的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)，如果電(dian)(dian)(dian)(dian)壓(ya)(ya)低于3V，要(yao)先(xian)進行(xing)預充(chong)電(dian)(dian)(dian)(dian)，充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)設(she)定電(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)1/10，電(dian)(dian)(dian)(dian)壓(ya)(ya)升到3V后，進入(ru)標(biao)準充(chong)電(dian)(dian)(dian)(dian)過程(cheng)。標(biao)準充(chong)電(dian)(dian)(dian)(dian)過程(cheng)為(wei)：以設(she)定電(dian)(dian)(dian)(dian)流(liu)(liu)進行(xing)恒(heng)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)升到4.20V時，改為(wei)恒(heng)壓(ya)(ya)充(chong)電(dian)(dian)(dian)(dian)，保(bao)持(chi)充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)為(wei)4.20V。此時，充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)逐(zhu)漸下降，當電(dian)(dian)(dian)(dian)流(liu)(liu)下降至設(she)定充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)1/10時，充(chong)電(dian)(dian)(dian)(dian)結束。

USB充電可能沒充滿

    電(dian)(dian)(dian)(dian)腦的USB輸出電(dian)(dian)(dian)(dian)壓為(wei)5V，一(yi)般都(dou)很精準，之所以大家覺得(de)USB充(chong)(chong)不滿，是(shi)因為(wei)USB輸出電(dian)(dian)(dian)(dian)流(liu)小，而充(chong)(chong)電(dian)(dian)(dian)(dian)的最后階段，需要有涓(juan)(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)。涓(juan)(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)是(shi)用(yong)來(lai)彌補(bu)電(dian)(dian)(dian)(dian)池(chi)(chi)在充(chong)(chong)滿電(dian)(dian)(dian)(dian)后由于(yu)自放電(dian)(dian)(dian)(dian)而造成的容(rong)量(liang)損失。電(dian)(dian)(dian)(dian)池(chi)(chi)在充(chong)(chong)滿電(dian)(dian)(dian)(dian)后，由于(yu)自放電(dian)(dian)(dian)(dian)損失的容(rong)量(liang)大約是(shi)標(biao)稱容(rong)量(liang)的5%。理論上說涓(juan)(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)要在充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)的1/500級別，USB電(dian)(dian)(dian)(dian)流(liu)只有500mA，涓(juan)(juan)流(liu)很小了，所以這個過程很慢(man)很慢(man)，你等不及拔下來(lai)，5%就沒了。

   用什么充，只有(you)電流的(de)區別

   另外手機數碼產品的鋰電池都有保護板，有限制最低電壓和限制充電電流的作用。而且現在的手機無論是用充電器還(huan)是(shi)用電(dian)(dian)腦USB，不都是(shi)那根線嘛，用什么充(chong)，只(zhi)有(you)充(chong)電(dian)(dian)電(dian)(dian)流的區別，都得(de)捅手機(ji)的“屁股”，只(zhi)要你用USB線充(chong)電(dian)(dian)，另一端是(shi)神馬，原理上(shang)都是(shi)一樣的，只(zhi)是(shi)充(chong)得(de)快慢問題。

   經測試，筆記本電(dian)(dian)(dian)(dian)腦USB口對(dui)手機(ji)充(chong)(chong)電(dian)(dian)(dian)(dian)，與座充(chong)(chong)對(dui)裸(luo)手機(ji)電(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)相比，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓略(lve)(lve)高（5V:4.2V），充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流略(lve)(lve)低（190mA:220mA），但換臺式機(ji)的USB口，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓仍為5V，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流漲為230mA。

   兩種充(chong)電(dian)方式并無(wu)明(ming)顯不同，USB充(chong)電(dian)會漏電(dian)的說法不正確(que)。