- No one remembers when they replace batteries and they don't leak.
- Everyone remembers when they replace batteries and they leak and damage something.
- Duracell and Energizer are the most widely used brands.
I suspect the leaks are statistically insignificant, and only happen due to imperfections in manufacturing process and natural statistical variance. If you could find a way to measure the internal pressure of the cell, that would be very interesting to see.
I found a book called "Battery Hazards and Accident Prevention" which claims alkaline cells may develop internal pressures of several hundred psi
![Shocked :o](https://www.eevblog.com/forum/Smileys/default/shocked.gif)
That explains the others here who have mentioned the AAAAs in 9V batteries exploding, and I've personally experienced an AA pop its seal while I was there, minutes after it had been rather abusively drained at over 3A (it sounded more like a very loud balloon popping, followed by a bubbling sound as the electrolyte poured out.)
Thus, discharged cells are already under high pressure, and I guess over time the seal just deterioriates and allows them to leak.