Funny story about batteries.
Being a young 11 year old desperate to learn from my dad on cars, he showed me the usual things to check. Tyres, fluids, lights and battery levels. He pointed out that the battery levels were at their lowest. Showed me what to do and then said hold on a minute, don't do anything as I need to go to the loo.
11 back when I was a kid, was still a kid but I didn't listen. I go carried away a bit and over filled one or two cells. Thinking I could correct this before he came back I found a straw.
At 11 I found out how fillings react with acid and how tooth enamel doesn't like it either