battery sizes

What are the sizes (diameter x length) of the various batteries used in mods? I am designing my first one and I want to plan it around a battery that will last the longest, have the slowest drain and have the most power. Rechargeable of course with no memory.
What would be the suggested battery that I am looking for and what are the dimensions of it.
Thanks

 

As I understand it, the number on the battery will give you the size...for example:

The name 18650 means that the battery has a diameter of 18mm and is 65mm long, but when a protection circuit is added the battery will be a few mm longer. How much longer will depend on the actual protection circuit and how it is mounted.

As far as your other requirements, I will let someone with a bit more knowledge than I have answer that.

 

and i think "0" means it's a round end/cylinder?/tubular?

 

Technically you are correct the last number being 0 regards it as a cylindrical battery. You do run into some cells like the 17335 or is it 17355, either way there is only a few out there that do not fall into the regular number sizing like that.


As Far as a recomennded size most feel that an 18650 will suffice for power requirements but there are larger cells like the 26500 (C) 26650(C+) and 32600 (D) batteries that you can build around.