Then I'd recommend looking into how to build a pack that doesn't need cooling, because that's a better, more efficient pack.
It will depend on each specific application exactly what you'll need in the pack, for cells, etc.
Since you won't say specifically what your applications are going to be and what they'll need the pack to do, we can't help you other than very generally.
If for some reason you have to use cells that can't handle the loads you'll put on them, and can't parallel enough of them to reduce the load to supportable levels, then you'll have heat generated in there.
If teh pack is not big enough to run for very long at a time, cooling is not necessary.
If the pack is big enough to run long enough to heat up inside and stay that way, *then* you need to cool it.
But it's still better to build a pack that doesn't heat up in the first place.