Got the cells in today. Not quite thrilled with them, I have to say.
Images (camera can't seem to focus well):
Appears to be standard cylindrical wrapped cathode/anode layers, encased in the same sort of foil material as the pouch cells. Ok, I'm guessing on the wrapped layers, but that's what it feels like, based on how solid it is.
Because of the foil material used for the shell, there is a small ridge along each side of the cell, where the foil is joined together.
About the same diameter as a AA, but about 5mm longer.
One tIny 2mm wide tab at each end, each about the thickness of the tabs on the pouch cells.
I laid them out, comparing against a 5S 5Ah 20C pouch cell pack. It looks like I could fit 18 of these in about 1.2 times the space of the 5S 5Ah pack. With termination bars/etc, I would say optimistically about 1.5x.
That brings us to 115.44Wh for these, vs 138.75Wh for 1.5x the 5S5Ah pack. Of course, you would also have extra space taken up by whatever termination system you use for the pouch packs...I'm gonna say optimistically you would probably end up breaking even.
So to sum up, I think that for building a large pack these are out of the question. If they had a more solid termination, maybe
they could be feasible, but like with 18650 cells, it would still probably require a large amount of engineering work to get them into a usable module. Interesting, and they seemed like a good prospect, but let's just say I'm glad I only got 10.
I'm sure I'll find some use for them, but it looks like my original thought of combining the energy density of 18650 cells with a fairly high discharge capability is a bust.
If anyone has any questions or anything they would like me to try with these cells, let me know and I'll see what I can do.
First on the list is some discharge tests.