@Mooch did a quick review here, which got me intrigued enough to buy one. I'm primarily interested in seeing whether it's useful to evaluate the condition of cells as they age, both with use and over time. So: =-=-=-=-=-=-=-= First up, four brand new Samsung 30Qs that I got in the same order as the meter. These are totally virgin; I've never even charged them. I'm going to put two of these in rotation in my most-used mod while I'll leave the other two on a shelf to age at ~3.7V. #1: 12.65 mΩ; 3.45V #2: 12.91 mΩ; 3.46V #3: 12.84 mΩ; 3.45V #4: 12.63 mΩ; 3.45V Those are some nice, consistent readings. =-=-=-=-=-=-=-= Next, four LG HG2s. I've had these for the better part of two years. Two of them have been in daily rotation in my most-used mod. That's a mechanical squonker, with a ~0.75Ω coil in it. It gets a freshly charged cell in it every day, while the other cell gets charged and then rests until the next day. So the two "used" cells each have about ~350 cycles on them, but these cycles are not at all hard. I use VP1/VP2 chargers exclusively so I always know the voltage of a cell when take it out of mod and put it in the charger, and they're basically never below 3.7V when they come out, and usually higher. The other two cells have fewer than 10 such cycles on them. Let's see if we can tell which cells are which: #1: 15.05 mΩ; 3.70V <- I think this one has zero cycles #2: 15.34 mΩ; 3.84V <- This one has fewer than 10, probably fewer than 5. #3: 20.8 mΩ; 4.16V #4: 21.5 mΩ; 4.15V It's quite obvious which pair has and been used and which one hasn't. I sure wish I had baseline readings on these from when they were new, but I don't; that's what the above 30Qs are for. =-=-=-=-=-=-=-= For laughs, some pretty old stuff: Four 3-1/2 - 4 year old VTC5s. Some have been cycled more than others. FWIW the #1 cells are about 6 months older than the #3 cells. #1A 15.32 mΩ; 4.19V #1C 15.15 mΩ; 4.15V #3C 13.25 mΩ; 4.01V #3D 13.62 mΩ; 4.16V All I can say here is: Wow! Still lower (or at least on par with) the substantially newer HG2s! One of the things that amazes me about these cells is that unlike other well-used or older cells, they don't drop in voltage after being charged; they show a solid 4.20V no matter how long I leave 'em in the charger. Two 3-4 year old LG HE2s. I don't know how many cycles these have. Not a lot. #1: 27.3 mΩ; 3.87V #2: 30.5 mΩ; 4.11V I find those readings a bit disappointing. A 3-4 year old Panasonic NCR18650PF (10A cell) with zero cycles on it: 21.1 mΩ 3.71V I'm amazed how low that resistance is -- as good as my well-used pair of HG2s. A Nitecore NL183 2300 mAh (unknown CDR): 68.1 mΩ 3.84V <- This thing came out of someone else's flashlight; I gave him a better cell. =-=-=-=-=-=-=-= That's it for now; I don't think I have any other cells here. I do have more cells in some of the other locations I hang out in, and will post more data when I get to those locations again. Of course I'll also update what happens to these cells as more time passes. PS: If anyone else bought one of these meters, jump in here, post data!