Included are four new Samsung 18650 26-F 3000 mAh batteries. Charger and related accessories sold separate. Please be advised that these flat tops are not compatible for series applications such as CREE flashlights, because they do not allow the cells to make contact with each other when stacked in series.
2600 mAh 18650-26F Li-ion Samsung Battery 4-pack
Posted on Candle Power Forums: "Jasonck08 sent me one of these cells to check out. Over the past 2 months I have been running it through a series of tests and have found that it is a very good cell. Let's get into the details... The cell came with a protection circuit, so I charged it up and ran some tests on it. As you can see, the protection circuit tripped during the 4 amp discharge. Capacity was lower than the labeled 3000 mAh (it actually came in at 2496 when discharged at 0.5 amps), but more on this later.
After this testing was complete, I then ran the cell through 20 charge/discharge cycles charging at 3 amps to 4.35 volts, and discharging at 3 amps to 2.75 volts. At the end of this cycling, I ran another discharge at 0.2 amps, and it came out to the same as the first discharge at 0.2 amps, so no damage was done. I then charged the cell up to 4.35 volts and let it sit on the shelf fully charged for 2 weeks. The discharge at 0.2 amps showed only a very slight change in capacity but not enough to indicate much damage.
At 6 amps of discharge the midpoint voltage was about 3.3 volts. It is nice if a Li-Ion cell can maintain a midpoint voltage of 3.5 volts, but at higher loads, the voltage drops off. The discharge rate for this cell holding a midpoint voltage of 3.5 volts was 4 amps. The mid point voltage during the 0.2 amp discharge was 3.85 volts.
These cells give you about 84% of labeled capacity when charged to 4.2 volts, which should greatly extend their cycle life, or full capacity if you have the ability to charge to 4.35 volts. You will have to contact Jason to figure out how to get a hold of some of these cells. The protection circuit adds some size to the cell. The bare cell is a typical 18650 cell. Jason has the details on the protection circuit, but it would be ideal if it could be set for a discharge rate of 6 amps.
All in all this is a strong cell. I am not sure what the advertised cycle life is, but I put over 50 cycles on it and there is very little change in capacity. I may have to try some higher discharge rates to see where things begin to break down, but on the other hand I may just use the cell in one of my lights..." - Tom, 'SilverFox,' Samsung 3000 mAh 18650 Testing