Well, I wasn't trying it on a fancy Atty. Just regular CE2s (2.4 Ohm) and a Vision Stone. None of the switches I got worked correctly.
The LED lights, but after a few puffs, they just don't deliver any current (checked with a multimeter). If I let them sit disconnected for some time, they will sometimes work for a bit, then shut down anew. Clicking very fast on them will sometimes make them restart. After tinkering with that for one week, I just got fed up and moved on. Mine were 14650.
Now, I'm not saying that every one of them is broken, just that quality control for the e-power seems way off. Plus the vendor that sold them just refused to take them back on the grounds that "they work fine for everyone else and you can sort of make them work". Sure, just don't count on further business with me.
If you order one, maybe you'll get a switch that works well. But maybe not.