Bought a pair of these almost exactly 6 months ago and are now very noticeably holding less charge. First time buyer of this brand having always used AW batteries in the past. Not sure if this is normal but I seem to recall my batteries lasting longer than this. Not sure if I would buy this brand again but there doesn’t seem much choice and I would prefer to buy from a trusted vendor like CdV

Efest got into trouble in recent years for apparently being a little economical with the truth and inconsistent about discharge rating and other specifications with previous models of this cell, but Moosh's independent testing of this model of cell sold by CdV would seem to suggest that these cells are what they say they are. (Google »moosh efest metallic purple« for more detail.)

And they're competitively priced and they come in a handy plastic box to ensure your charged spares don't get shorted in your bag (*very* important!)

This is my second pair of Efests and they do the job for me (but I currently only vape at around < 40W). Even the questionable earlier model (which I bought elsewhere maybe 15 months ago and still use) have never given me any trouble, though for most of their life they were only run at about 5W.

Unless they prove unreliable at higher power in the long term, I'd buy them again. But I trust anything CdV sells because it's clear from talking to them that they know what they're doing.

If you use a dual-cell mod, be sure to mark your cells as pairs and avoid mixing cells between pairs. It's probably a good idea to mark them in a way that you can alternate left and right so they get even wear. I mark my pairs with a number and an arrow because that suits my mod (an Aspire Archon).

These are 'unprotected' cells as required in sub-Ω applications, therefore can be dangerous if mistreated. Handle with care, never overcharge or over-discharge and never discharge at rate higher than specified. Never use unprotected cells in mech mods. These are not the sort of warnings you can safely disregard. But you'll get all that stuff when you buy 'em.