Slightly off-topic - There Chemistry in its Element podcast is a good listen. 15 mins every week talking about a different compound/element: <a href="https://www.chemistryworld.com/podcasts" rel="nofollow">https://www.chemistryworld.com/podcasts</a>
I had a friend in school that noticed that fresh new batteries are much softer than old dead ones.<p>All of his devices had batteries with bite marks in them.
Not sure for which batteries this works. After seeing that YouTube video some time ago, I tried to reproduce it at home with some AAA batteries. Didn't work.
> Alkaline AA batteries are one of the most common battery types [...]<p>Is this really true anymore? I use almost exclusively rechargeable batteries (NiMH & Li-ion & LiFePO4) our my household. Only very low power devices such as clocks run on alkaline batteries.