These are all the different 18650s I have for now. I've read that OEM manufacturers tend to have their own design of the top-caps (for non-button-top designs).
Can someone help identify some of the above? (I've only bought a few 18650s since there are few good sellers locally, and still waiting for my online foreign order to arrive).
"1" is an "UltraFlre 6800mAh" (no, it's not UltraFire) that came with a generic "XML T6" flashlight (bought from local shop), real capacity is around 150mAh (1A drain), and around 300mAh at lower drain rate. It weighs the lightest at around 25grams.
"2" is an "UltraFire 4200mAh" that came with another generic "XML T6" flashlight (bought from local shop), real capacity is around 900mAh (at least this one is more usable than the above one).
"3" is a LiitoKala protected NCR18650B I bought from AliExpress, capacity seems to range from 3100-3300mAh..
"4" is a "Sanyo UR18650GA" (2200mAh nominal) from a laptop battery, got 6 of these from the laptop battery but all of them can overheat when charging (does not terminate charging) -- I was still a bit clueless since I couldn't get my hands on "real" 18650s, so I had to make do with laptop pulls. Each of them still have around 900-1000mAh capacity (as long as charging is stopped manually) -- they start to heat up at around 3.90-3.95v (voltage doesn't go up). Stopping the charging, letting them cool down, then charging again at a lower rate (eg. 0.5A) seems to let them go up to around 4.15-4.20v (sometimes they will terminate automatically after this step). So it's not safe to charge these without supervision (even the "smart" chargers don't seem to terminate with these batteries).
"5" came from a cheap single-cell powerbank from a friend (I asked some friends if they have powerbanks that don't work and this was given to me). The 18650 was labeled "ICR18650NQ", which seems to be supposedly 2600mAh, but I don't know if it's a real Samsung or not. This is my lowest capacity "working" 18650, only has around 70mAh capacity (1A drain rate), and around 150mAh if draining at lower currents. It does terminate charging properly. Also, after it gets drained, the voltage recovers very quickly, so that one could drain it again at a low drain rate (eg. 0.2A), multiple times. Not much practical use, but I'm currently "using" it for testing chargers since it charges to full very quickly...
Does anyone know if based on the top-cap design, is it a real Samsung ICR18650NQ?
"6" is supposedly an LG HG2 3000mAh that I bought from a local battery store, however, upon testing, it has only around 2500mAh (I got 2 of these, and both are only around 2500mAh). I'm not sure if that means it's not a genuine LG HG2, or there's something wrong with the battery (it works normally, other than the reduced capacity). The seller insists it's a real LG, even when I mentioned why my capacity test only measures it as around 2500mAh instead of 3000mAh. Anyone knows if this is a fake or some other explanation for reduced capacity? What happened to the missing 500mAh if it were a real LG HG2?
"7" is my sole Samsung INR18650-30Q, so far my "prized" 18650 since all my other Samsung INR18650-30Q from Banggood got cancelled ("does not ship" even with protective plastic case). This one was ordered from BG for the "BLF A6 with INR18650-30Q" -- the battery was placed inside the flashlight (the 18650 has a plastic tape on the bottom during shipping). Tested capacity is really 3000mAh
"8" labeled Samsung ICR18650-22F (2200mAh) came from an HP laptop battery (6pcs 18650s, but 2 were completely dead - 0volts, and I tried placing them in the XTAR VC4 charger, but the 2 18650s are not detected and couldn't be revived), but luckily 4pcs are still usable, with remaining capacity of around 900-1000mAh. These 18650s terminate charging normally (unlike the Sanyo UR18650GA laptop pull which do not terminate charging normally)
"9" "pink" 18650, no other label, came from a USB rechargeable fan. Real capacity for now is around 600mAh. Can someone help identify what OEM manufacturer is this 18650?
"10" is from a local battery shop, it's labeled 2000mAh, but no other significant markings, other than the name of the local battery shop "Elfoh". Real tested capacity is around 1800-1900mAh. Can anyone help identify the OEM manufacturer based on its top-cap design? It doesn't look like any of the other top-cap designs from my other 18650s.. well, now that I took a closer look, it does look a bit like the "5", which is supposedly a "Samsung ICR18650NQ". So, is it a Samsung OEM or something else?
"11" is from a single-cell powerbank that I bought locally (initially I couldn't find 18650s locally, so I thought of buying a powerbank and harvesting the 18650 inside), and this powerbank has a single 18650 labeled "2200mAh", although my tested capacity is more like 1900-2000mAh. There is a barcode design marking, and based on Internet research, it seems to be a "CJ" or Chang Jiang Battery (there is no "CJ" marking on this 18650 though), but it does look like the other CJ 18650s I find on the web, so I'll guess that this is indeed a "CJ" brand 18650, except that it's missing 200mAh (supposed to be 2200mAh).