1、鋰電池充電器設計方案
11.1V鋰電池常用于涵道機、固定翼、直升機等航模中,具有放電穩定,工作溫度寬;允許較大的充電電流、充電速度快,僅需1~2個小時就(jiu)可以充滿(man);無記憶效應(ying);自放電(dian)率低,儲存壽(shou)命長;能量高、儲存能量密(mi)度大;輸出電(dian)壓(ya)高(單節鋰電(dian)池(chi)的額(e)定電(dian)壓(ya)一般(ban)為3.6V,而單節鎳氫和(he)鎳鎘電池的(de)電壓只有(you)1.2V)等(deng)優(you)點(dian)。在(zai)對鋰(li)(li)電(dian)(dian)池進行(xing)充(chong)電(dian)(dian)時要防(fang)止過(guo)(guo)度(du)充(chong)電(dian)(dian),如果充(chong)電(dian)(dian)電(dian)(dian)壓高于(yu)規定電(dian)(dian)壓或充(chong)電(dian)(dian)電(dian)(dian)流大于(yu)規定電(dian)(dian)流,就會(hui)損壞鋰(li)(li)電(dian)(dian)池或者使(shi)之(zhi)報廢。在(zai)過(guo)(guo)充(chong)電(dian)(dian)的情況下,能量(liang)過(guo)(guo)剩鋰(li)(li)電(dian)(dian)池溫度(du)上升,電(dian)(dian)解液將(jiang)分解產生氣(qi)體,使(shi)之(zhi)內壓上升而導致自燃或破裂(lie)的危險。通鋰(li)(li)電(dian)(dian)池在(zai)使(shi)用時也要防(fang)止過(guo)(guo)度(du)放(fang)電(dian)(dian),過(guo)(guo)度(du)放(fang)電(dian)(dian)會(hui)導致電(dian)(dian)池特性(xing)(xing)及耐久性(xing)(xing)變(bian)差,可(ke)充(chong)電(dian)(dian)次數降低。
2、充電電路結構設計分析
鋰電池在充電過程中需要控制它的充電電壓和充電電流并精確測量電池電壓,根據鋰電池電壓將充電過程分為四個階段。階段一為預充電,先用0.1C的小電(dian)(dian)流對鋰(li)電(dian)(dian)池進行預充電(dian)(dian),當(dang)電(dian)(dian)池電(dian)(dian)壓≥2.5V時(shi)轉到下一階段。階段二(er)為恒流充(chong)電,用1C的恒(heng)定電(dian)流(liu)對鋰電(dian)池快速充電(dian),點電(dian)池電(dian)壓≥4.2V時轉到下一階段。階段三為恒壓(ya)(ya)充(chong)電,逐漸減小(xiao)充(chong)電電流,保證電池(chi)電壓(ya)(ya)恒定=4.2V,當充電電流≤0.1C時轉到下一階段(duan)。階段(duan)四為(wei)涓(juan)流充(chong)電(dian),恒壓充(chong)電(dian)結束后,電(dian)池已經基本(ben)充(chong)滿,為(wei)了維(wei)持電(dian)池電(dian)壓,可以(yi)用(yong)0.1C甚至更小的電(dian)流對電(dian)池進(jin)行補充充電(dian),到此(ci)鋰(li)電(dian)池充電(dian)過(guo)程結束。
3、鋰電池充電器充電流程
電源未接上時(shi),電路(lu)板(ban)上的LED燈不(bu)亮;
電源接上(shang)電路板,綠色LED持(chi)續亮著,此時(shi)電路板(ban)等待鋰電池置入;
鋰電池放入后,則開始充電,LED變成橙色;
當鋰電池達到(dao)充飽的(de)條件(jian)時,則(ze)停止充電,LED變成橘色;
鋰電池充飽后,電池移(yi)走,LED變成綠色,等(deng)重(zhong)新置入鋰電池充(chong)電;
在充電(dian)(dian)過程(cheng)中,會(hui)顯示充電(dian)(dian)百分比。
LED燈(deng):
持(chi)續(xu)綠色:等待電池置(zhi)入(ru);持(chi)續(xu)黃色:充(chong)電中;持(chi)續(xu)橘色:電池已(yi)(yi)充(chong)飽充(chong)或(huo)已(yi)(yi)充(chong)6小時;閃爍橘色:警示訊息(輸出短路、正負極顛倒、溫度異常)。