A123 Systems has a popular LiFePO4 power 26650 cell. Sony and Moli have hybrid and IMR 26650 respectively, both sometimes encountered in tool packs in place of a 2P 18650 pack. What I don't know is where the high energy 26650 cells come from, name-brand wise. Do they have a name brand supplier, or is that sector all Chinese generics?
Similarly, Sanyo and Sony make 14500 cells (including a Sony power cell and some Sanyo energy cells that are honestly 800mAh) and have for some time. These companies also have 14430 cells, which as far as I know have never been put to flashlight use.
I have heard of 16340 in camera packs
Sanyo developed a 16650 cell to meet a need of a laptop manufacturer and now that cell is out there too. I would wonder if the 17670 was a similar cell historically (it seems to be an old size).
Sanyo and Pana have 18500 cells.
However, the 10180, 10280, 10440 series is one of those oddballs. I have never heard of these "officially", only generic from China.
What I would like to know is what is under the shrink wrap on these cheap Chinese type of 16340, 26650, etc. cells that appear to have no name brand alternatives nor "proper" (assembled into packs by an authorized buyer) application or market outside of our uses for them as loose cells. Specifically, is the button top an aftermarket welded-on piece as seen when name brand cells are resold as a button top version? Or, is the button top the actual positive terminal - meaning these cells were NEVER intended to be packed at all, but specifically meant to be sold as they are to people like us?
I suspect that this is the case. Name brands won't sell ya cells unless you can prove you will comply with requirements, so getting your hands on bare cells as a hobbyist is kind of a gray market, surplus, used, second-rate, unpredictable business sometimes. The Chinese companies care much less about liability and they may specifically be aiming to exploit the market for raw cells to be dropped into flashlights and the like.
