筆記本電池的作用是使筆記本電腦在沒有交流電源的情況下可以待機工作，它主要是靠里面的電芯來維持能量，也可以說電芯的質量決定了電池的質量，正常的筆記本電腦電池，其待機時間應不低于2h。使用可充電電池是筆記本電腦相對臺式機的優勢之一，它可以極大地方便筆記本電腦的在各種環境下使用。最早推出的電池是鎳鎘電池（NiCd），但這種電(dian)(dian)池具(ju)有“記憶效應(ying)”，每次充電(dian)(dian)前(qian)必(bi)須(xu)放電(dian)(dian)，使用起(qi)來(lai)很不(bu)方便，不(bu)久就(jiu)被(bei)鎳氫電(dian)(dian)池（NiMH）所取(qu)代，NiMH 不(bu)僅(jin)沒有“記憶效應(ying)”，而且每單(dan)位重量可多(duo)提(ti)升10 % 的電(dian)(dian)量。

在日常使(shi)用(yong)的時候，應(ying)該(gai)盡量(liang)減少(shao)使(shi)用(yong)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的次(ci)(ci)(ci)(ci)數，因為筆(bi)記(ji)本電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的充(chong)放電(dian)(dian)(dian)(dian)(dian)次(ci)(ci)(ci)(ci)數有限，每(mei)充(chong)一(yi)次(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)壽(shou)命就減少(shao)了一(yi)次(ci)(ci)(ci)(ci)，所以(yi)如果在使(shi)用(yong)外接(jie)(jie)電(dian)(dian)(dian)(dian)(dian)源時，應(ying)該(gai)將(jiang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)取下來，如果經常在一(yi)天中多次(ci)(ci)(ci)(ci)插拔電(dian)(dian)(dian)(dian)(dian)源，且筆(bi)記(ji)本裝有電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，對電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的損壞更大，因為每(mei)次(ci)(ci)(ci)(ci)外接(jie)(jie)電(dian)(dian)(dian)(dian)(dian)源接(jie)(jie)入就相當于(yu)給電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)一(yi)次(ci)(ci)(ci)(ci)。此外，筆(bi)記(ji)本電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)有記(ji)憶效(xiao)應(ying)，部分充(chong)電(dian)(dian)(dian)（不到100%）會導致(zhi)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)芯的(de)化學性(xing)能(neng)(neng)不一致(zhi)，使得(de)電(dian)(dian)(dian)池(chi)性(xing)能(neng)(neng)會退(tui)降，因而一定要(yao)將電(dian)(dian)(dian)量用(yong)盡后再充(chong)（電(dian)(dian)(dian)量低于1%），這是避免記(ji)憶效應的(de)最好方法，否則電(dian)(dian)(dian)池(chi)很容易暫時(shi)失去供電(dian)(dian)(dian)能(neng)(neng)力