YSK that there is an easy way to tell if a AA battery is dead. Drop the battery onto a hard surface from 7-10 cm(3-5 in) .high. A charged battery will hit the ground with a thud and either stand straight up or fall directly over. A dead battery will bounce.
from /r/YouShouldKnow
YSK，有一個簡單的方法來判斷AA電池是否沒電。將電池從 7-10 釐米（3-5 英寸）高的地方摔在硬地上。充了電的電池會砰的一聲砸在地上，然後直接站起來或者直接摔倒。沒電的電池會反彈。