Some fun facts about alkaline batteries:
- They are technically rechargeable. Not very often and their capacity deteriorates quickly, but there are specialized alkaline chargers that allow you to recharge them a couple of times.
- You can tell whether they're full or empty if you drop them on a hard surface. Empty ones will bounce slightly and make a "brrrt" sound, while full ones will stop immediately and make more of a "tock" sound.