I've noticed something in common with all the bad ones pictured here, they all have "EGO" stamped on them.
I recently bought an eGo style starter kit, it came in a blister pack but has no markings on it & no manufacturer on the packaging whatsoever. It was sold to me as a 1100mAh battery & certainly the case measures up (from this pic it does anyway, note this is not a pic of my kit, just a random pic I found)....
Anyway, I think it really might be an 1100mAh battery, as I've had it since Monday, charged it up when I got it (it must've been charged as the light went green pretty quick), & I used it until Tuesday evening, when it was still working but I gave it a charge anyway. It's now Thursday evening & it's still going strong. (I'm not a chain vaper, but I do actually
use the thing.
I'm not going to take it apart, as it's still working fine, but I think the moral of the story (although perhaps not the best advice) may be, if it's cheap & pretending to be expensive (IE: Has "EGO" written all over it) then you can pretty much guarantee it's not going to be much good (like the old saying, if it seems too good to be true, it probably is). The way I see it, mine isn't pretending to be anything it's not, it's just plain with nothing written on it at all. & the quality doesn't seem too bad either. The only worrying bit is there's no mention of a manufacturer anywhere on the packaging.
When it gives up the ghost I will, of course, be taking it apart. I have a workshop in the garden full of tools, engines & old motorbikes, I
LOVE taking stuff apart!