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(ge)小時就可以(yi)充滿;無(wu)記(ji)憶效應(ying);自放(fang)電(dian)率低,儲(chu)存壽(shou)命長;能(neng)量(liang)高、儲(chu)存能(neng)量(liang)密(mi)度(du)大;輸出電(dian)壓高(單(dan)節鋰電(dian)池的額(e)定電(dian)壓一般(ban)為3.6V,而單(dan)節鎳(nie)氫(qing)和(he)鎳(nie)鎘電池的電壓只(zhi)有1.2V)等優(you)點(dian)。在對鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)池進(jin)行充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)要防(fang)(fang)止過(guo)度(du)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian),如果充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)高于(yu)規定電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)或(huo)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流大于(yu)規定電(dian)(dian)(dian)(dian)(dian)(dian)流,就會損壞(huai)鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)池或(huo)者使(shi)之(zhi)報(bao)廢。在過(guo)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的情(qing)況下,能量過(guo)剩鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)池溫度(du)上升,電(dian)(dian)(dian)(dian)(dian)(dian)解液將分解產生氣(qi)體,使(shi)之(zhi)內壓(ya)上升而導(dao)致自(zi)燃或(huo)破裂的危險(xian)。通鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)池在使(shi)用(yong)時(shi)也要防(fang)(fang)止過(guo)度(du)放電(dian)(dian)(dian)(dian)(dian)(dian),過(guo)度(du)放電(dian)(dian)(dian)(dian)(dian)(dian)會導(dao)致電(dian)(dian)(dian)(dian)(dian)(dian)池特性及耐久性變差,可充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)次數降低(di)。
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的小電流對鋰電池(chi)進行(xing)預充電,當電池(chi)電壓(ya)≥2.5V時轉到下一階(jie)段。階(jie)段二為恒流充電,用(yong)1C的恒(heng)定電(dian)(dian)流對鋰電(dian)(dian)池(chi)快(kuai)速充(chong)電(dian)(dian),點電(dian)(dian)池(chi)電(dian)(dian)壓≥4.2V時(shi)轉到下(xia)一階段。階段三為恒壓(ya)充電(dian)(dian),逐漸(jian)減(jian)小充電(dian)(dian)電(dian)(dian)流(liu),保證電(dian)(dian)池電(dian)(dian)壓(ya)恒定=4.2V,當(dang)充(chong)電電流≤0.1C時轉到下一階(jie)段。階(jie)段四為(wei)涓流充電(dian),恒壓(ya)充電(dian)結束后,電(dian)池已經(jing)基本充滿(man),為(wei)了維持(chi)電(dian)池電(dian)壓(ya),可以用(yong)0.1C甚至更小的(de)電流對(dui)電池進行補充充電,到此鋰(li)電池充電過(guo)程結束。
3、鋰電池充電器充電流程
電源未接上時,電路板上的(de)LED燈不亮(liang);
電源接上電路(lu)板,綠(lv)色LED持(chi)續亮著(zhu),此時電路板等待鋰(li)電池(chi)置入;
鋰電池放入后,則開始充電,LED變成橙色;
當鋰電池達(da)到充飽的條件時(shi),則停(ting)止充電,LED變成橘(ju)色;
鋰(li)電(dian)池(chi)(chi)充飽(bao)后,電(dian)池(chi)(chi)移走,LED變成綠色,等重(zhong)新(xin)置入(ru)鋰電池充電;
在充電過程中(zhong),會顯(xian)示充電百(bai)分比。
LED燈:
持(chi)續(xu)(xu)綠色(se):等(deng)待(dai)電(dian)池置(zhi)入;持(chi)續(xu)(xu)黃(huang)色(se):充(chong)(chong)電(dian)中;持(chi)續(xu)(xu)橘色(se):電(dian)池已充(chong)(chong)飽充(chong)(chong)或已充(chong)(chong)6小時;閃爍橘色(se):警示訊(xun)息(輸(shu)出短路、正負(fu)極顛倒、溫度(du)異常)。