1cm x 1cm x 2.5 cm?

[one_raven]

The mod I am looking to do requires a battery to fit in a space that is approximately 1cm square by 2.5cm tall.
I want it to be a fully protected battery and I want the battery to last all day.
I can work with a round or square battery (though square may be a bit easier).
It can be LiIon or LiPo.
I am not too particular on voltage anywhere from 3.7 to 5 would be fine.

Any suggestions?

Does anyone have a good resource where I can look at a grid of features of the batteries they sell so I can narrow it down?
Thanks

[one_raven]

I might be able to go as large as 1 x 1.5 x 3.

Is this possible at all?

[Shreck]

You definitely are not going to find one that size that will last you all day.
Thats an awful small battery.
Your talking like 3/8" diameter x 1" long, for us American folk.
I dont know of one that is that small even.

[Nuck]

The smallest useful bat is going to be the 10440 10mm diameter by 44mm long. Its somewhat close to fitting your requirements. It won't however, last all day as they are only approx 300mah each.

I'm not aware of any bats small enough will fit your size requirements and there is no way to get an all day bat in such a small space.