Most helpful critical review
382 of 390 people found the following review helpful
Poor battery, and not for high current applications.
on July 16, 2011
I purchased two sets of Ultrafire 18650 3000mAh batteries with charger. The included charger works well for travel needs but does not seem to have two independent charging channels, as there is only one charge status LED. It works well enough for casual use with inexpensive cells in my collection, but a higher quality charger such as the Pila IBC is a good investment if you get serious and want the most out of your more expensive 18650 batteries.
My only complaint is these batteries after being freshly charged cut out under a high load because of the protection circuit board which seems to be current limited to only around 2.5 Amps. For instance, when trying to drive a Ultrafire WF-502B or WF-501B flashlight with the 900 lumen Cree XML-T6 P60 LED drop-in on max power, it will only illuminate for a couple seconds and then cut off. Running it for a few minutes on medium power to partially drain the battery then allows it to run continuously on high power. The measured current draw on high power was 2.46 Amps. This suspicion was further confirmed when I cut open a cell and looked at the protection circuit card inside and found only one MOSFET driver IC, and two empty spots for additional MOSFET driver ICs. (Most other brands of 18650 batteries can sustain 5 to 7 Amps and contain two or three MOSFET drivers on the protection circuit card)
So if your needs are for long storage life with a moderate discharge rate, this is a great battery and a good deal.
Update to my original 07/16/2011 review above.
After having used these batteries for over a month now, and having gone through several charge/discharge cycles, I downgraded this review from three to one star. I purchased two sets (four batteries) from HULATU LLC trading/CREE-Flashlight along with the included wall type travel chargers. What I found is the advertised capacity of 3000mAH for these Ultrafire 18650 batteries is a complete misrepresentation. The label on the battery says 3000mAH, however when I tested them I only observed 980mAH to 1070mAH discharge capacity for all four of the batteries I received. This discharge test was done using a Turnigy Accucell 8150 with a discharge rate of 600mAH, discharging the battery from 4.20VDC down to 3.00VDC. By comparison, I tested two inexpensive Tenergy 2600mAH 18650 batteries using the same setup and they came in at a reasonable 2460mAH and 2520mAH discharge capacity.
So unless your capacity needs are very light, don't waste your money on this brand of 18650 battery.