These batteries are sold from many China shops, I have tested from 3 different shops and there is wide differences and none of the batteries are good.
Official specifications:
Model : 18650 (Protected)
Voltage: 3.7V
Capacity : 3000mAh
Size : 65mmx Ø18mm Weight: 35g
Recharge up to 800 times
Xenon bulbs are not suitable
These batteries are from the UltraFire shop that insists that they sell genuine UltraFire with good quality.
The two batteries has a huge difference in capacity, especially at low currents.
It does not look like this battery has a over current protection or maybe it is at a higher current than the battery can supply. The A battery failed after one test.
UltraFire BRC18650 3000mAh (Red-silver) cnq
Official specifications:
Genuine Ultrafire 3000mAh 18650
Real capacity: 2900mAh (-100mAh / + 100mAh)
Internal PCB protection prevents under-voltage at 2.5V and over-voltage at 4.25V. UNIQUE INTERNAL PCB!
Diameter 18.6+/-0.2 mm (Note: Diameter may not fit all flashlights)
Height 66.5+/- 0.2mm
Weight (Typical) Approx. 46 g
Nominal Voltage: Average 3.7V
Cut-off Voltage: 2.5V
Internal Impedance: less or equal to 180 milli-ohm (with PTC)
Cycle Performance: 90% of initial capacity at 400 cycles
Cycle life: > 500 cycles
Charge: Current = 0.5C mA Voltage = 4.2 V End Current = 0.01 mA
Discharge: Current = 0.5C mA End Voltage = 3.0V
This is the most expensive UltraFire 3000mAh than cnq has, these are supposed to genuine UltraFire.
The two batteries has a huge difference in capacity, especially at low currents.
It does not look like this battery has a over current protection or maybe it is at a higher current than the battery can supply. The A battery failed after one test.
These UltraFire does not have the same performance as the two other pairs.
There is a fairly good match between the batteries.
On these UltraFire the protection works.
Conclusion
The genuine UltraFire batteries are not very good with very different capacity and problems with the protection circuit, the DX version is better (At least the ones I got). None of the batteries are close to the rated capacity.
The internal resistance is also way to high for the genuine batteries.
I will rate these batteries as BAD, the DX ones are acceptable for a cheap battery, but because there is many different UltraFire 3000mAh on the market, I would not trust them.
Notes and links
Due to the wide difference between batteries from the same dealer, I have not included them in the charts, but only in the comparator.
It probably has less than 2000 mAh. I will think about it, but remember that it will probably be between one and two months from I order it, until I can publish the test.
Thanks, HKJ. I stopped buying these long ago and am glad for that. I still use a few of them when they actually work. Some of my lights (like Balder BD-2) will not even function on high using these cells. They should come with a big Avoid label on them.
i just did a rundown test on a pair i bought off amazon a little over 1/2 year ago, put em in my bc40, till the light shut off. when i measured them, one was 3.4v, the other had the protection tripped :bigsmile: , went under 2.8, great batteries they are, needless to say i am going to get some good cells soon and retire them asap
Bid at an auction on ebay and won four of these for ridicilous money and 1 is a complete dud, it doesnt work. Multimeter says 3,8v but it can only produce a dimly glowing LED (what you call halo?) that you can look straight into. Charging it with my WP2 II produced the interesting effect of voltage dropping the more I charged it. Put it in the WF-188 and it made it happier (but maxed out at 3,85). I dropped one on the floor when I unpacked them, don’t know if it’s that particular battery though.
The rest charges to 4,10-4,15v and two of them works OK, one flickers in my HD2010 on high.
Conclusion: If you pay less for four 18650’s and shipping costs from China than you do for a coffee at 7-Eleven, chances are the cells aren’t very good. But I didnt expect anything else. And two of them work just fine (for now).
I made some discharge test with the cheap “Ultrafire” 18650 “3000” mAh batteries I have.
Since I can’t discharge these to 2.8V but only to 3.0V (1A), can I determine the full capacity of the battery?
The results of the discharge to 3.0V 1A, was around 1200 mAh.
That depends on the battery. Some batteries can easily be discharge above 3 volts, some other cannot. Look at the curve, if it is nearly vertical at the end, the battery is fully discharged.
In my test the batteries are not always fully discharged, especially not at 5A current.
I have an original imax B6 charger, I can’t export the results.
According to the battery life in flashlight usage, it must be around 2000 mAh.
Not bad for a “3000 mAh” cell???