要想辨別電動汽車（EV）中的鋰離子（Li-ion）電池電芯是否具有可接受的自放電特性，您需要采用恒電位測量法。 將穩定的低噪聲直流電源設置為與電芯的開路電壓（OCV）相匹配。 通過微安計連接直流電源和電芯，以便測量直流電源與電芯之間的電流。 當電芯自放電時，直流電源會輸出電流，讓電芯保持恒定的電壓和充電狀態。當直(zhi)流電(dian)(dian)(dian)(dian)源與電(dian)(dian)(dian)(dian)芯(xin)(xin)達到(dao)平衡后，自(zi)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流從內部(bu)供(gong)應轉為由直(zhi)流電(dian)(dian)(dian)(dian)源從外部(bu)供(gong)應。 此時，可以使用(yong)微安計測(ce)(ce)量自(zi)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流。 恒電(dian)(dian)(dian)(dian)位測(ce)(ce)量法需要用(yong)到(dao)一臺自(zi)放(fang)電(dian)(dian)(dian)(dian)分析儀，該分析儀能(neng)夠在施加(jia)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)之(zhi)前將電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)快速匹配到(dao)電(dian)(dian)(dian)(dian)芯(xin)(xin) OCV 的(de) +/-5 µV 范圍內。 這樣能(neng)夠最大限度減少新的(de)充電(dian)(dian)(dian)(dian)或放(fang)電(dian)(dian)(dian)(dian)變化(hua)，盡量縮短測(ce)(ce)量穩(wen)定(ding)時間。 施加(jia)到(dao)電(dian)(dian)(dian)(dian)芯(xin)(xin)上(shang)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)也(ye)必須保持穩(wen)定(ding)，才能(neng)最大限度降(jiang)低自(zi)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流測(ce)(ce)量中持續(xu)的(de)電(dian)(dian)(dian)(dian)流噪聲。