Why only button top? Batteries are not manufactured that way. I know the answer and despite I can sort of accept it, it is not of my liking.
If anything a wide button top is better, providing extra contact surface.
When I look at the source of the first post - there are image links there.
Copying a link and opening in another tab shows me image - so this is working.
However when I reload the BLF site and look at network requests - my browser tries to load the images but your server refuses to give them with error “403 Forbidden”.
I don’t know maybe your web admin added some embedding “protection”?
Anyway the issue seems to be with your image host.
Sometimes you get higher capacity at higher discharge rate because the battery “doesn’t get discharged completely”. This is why energy is a much precise way to measure the real capacity because it can be translated directly into lumens/hours.
I concur energy is a more precise way of measuring absolute performance or delivered energy.
The area below the line curve is delivered energy, which is the integral of the voltage curve over the delivered capacity for the given voltage range and discharge rate. Or something like that, haven't touched formal maths for ages.