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157 of 163 people found the following review helpful
on February 1, 2012
As a reseller of high-end LED flashlights I also have to provide 18650 batteries and chargers. I've spent the last 2 months importing batteries and chargers and doing some "real world" testing. I used Balder BD-2 flashlights to test my 18650 batteries. I won't give you my full results as it would take up a lot of space, but here is a sampling of high end to low end:

EagleTac branded protected Panasonic 3100 mAh - 155 minute average on high. (Sat for 4 days before test.)

SZOBM Black label protected 2800 mAh - 112 minute average on high. (Sat for 2 weeks before test.)

SZOBM Black label protected 2400 mAh - 114 minute average on high. (Fresh Charge.)
SZOBM Black label protected 2400 mAh - 111 minute average on high. (Sat for 2 weeks before test.)

SZOBM Blue label unprotected 2400 mAh - 106 minute average on high. (Fresh Charge)
SZOBM Blue label unprotected 2400 mAh - 96 minute average on high. (Sat for 2 weeks before test.)

UltraFire protected Red/Silver 3000 mAh - 80 minute average on high. (fresh charge)
UltraFire protected Red/Silver 3000 mAh - 28 minute average on high (Sat for 2 weeks before test.)

All of these batteries I bought brand new, directly from my distributor or from China. None were sold from the auction site. The Panasonic outperformed these UltraFire's by 94% (nearly twice as long) with a fresh charge, or 454% after sitting for a couple of weeks. Even the no-name SZOBM batteries I tested significantly outperforms these Ultrafire batteries by an average of 38% longer run times. Do yourself a favor and don't invest in any battery with the word "Fire" in it.
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59 of 65 people found the following review helpful
on June 28, 2010
This is a very decent 18650 secondary cell (not a battery) with the Ultrafire brand. Not sure if the 3000mAh claim is true, but I can vouch for the fact that it lasts a bit longer than other cells I own (a few Trustfires, a few Ultrafires and a few Tenergys, rated between 2400mAh and 2600mAh).

The button top feature means that they will work well in spring-less flashlights (no need for a magnet-button).

The protected feature means they have a chip on board that protects it from over-charge and under-discharge. If over-charged (over 4.2V in layman's terms) the cell overheats and may explode (it's called "thermal runaway"). The explosion itself is a chemical rupture-explosion, a very nasty thing. If under-discharged (used under load until it drops under 2.75V, in laymen's terms), a chemical reaction makes the cell unstable, dangerous and unusable. The chip onboard should protect against this. If you are running a flashlight until it gets dim and hits the low treshhold, the cell shuts down - you should throw it away. I never run my cells below 3V, and my charger takes care not to charge more than 4.2V.

Never leave the charger unattended overnight. Put the charger in an area where a potential explosion does the least damage (a fireplace, if you have one, is great). When the little light on the charger turns green, take it out. Get a voltmeter and measure. Under no load, the voltage should be 4.0-4.2V. The nominal voltage is 3.7V, that's what should read when the cell is under load. Let is sit 20-30 mins after a fresh charge and before using it - this cools it and "settles" the chemistry inside.

Your charger should also protect against overcharging. Naturally (duh...), you must use a charger made for charging 18650 cells. This cell will not even fit in a Wallmart/Kmart/Target found charger. This cells are not available in retail. Their size is different from AA, AAA, C, D, etc... And yes, you would charge a Li-Ion cell with a... Li-Ion charger.

As far as compatible chargers, just type 18650 in the Amazon search and go down the list. The DSD charger is very popular and praised for it's simplicity, you also can't go wrong with Tenergy products, it's a US company with a lot of pride in quality control. Personally, I use a Pila charger and I have several DSD ones.

Amazon did not do anything wrong here, description is fine and all specs are accurate, so please disregard the previous rant against Amazon (and not related to the product).

This cell is great. If you know what a 18650 is for and what it does, then buy this with confidence. If you don't know what this is, please step away from this page, this is not for you and you might get hurt - chemical fire is very nasty.

I use these cells primarily in hi-power Cree led flashlights. If you want to build a pack (for example, in robotic applications), you're probably better off going with unprotected button-less. After you solder your pack together (careful not to overheat - heat is another Li-Ion fire starter) you should attach a custom made protection circuit to the entire pack. The protection circuit is a must-do requirement!

Most importantly - use common sense. If you don't have one, do not buy/use these cells.

Price is a bit steep, but if you want crazy life-on-the-edge performance, and more importantly, you know what you're doing, then this cell is for you.
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23 of 24 people found the following review helpful
on August 12, 2011
I bought four different ones before I completed a thorough test drive. My bad. The results are as follows: All four batteries store only half the juice. They were even charged on a different charger several times. The same result. I bought two new ones from Battery Junction and got twice the discharge. In short, I believe these are factory rejects coupled with a not too bad little charger.
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8 of 9 people found the following review helpful
TOP 500 REVIEWERon December 13, 2012
It's not very often that I buy a product on Amazon that performs so far below expectation that it not only disappoints, but angers me because I feel duped. These batteries have justly earned the aforementioned dubious distinction.

I needed batteries for my new Eagletac - P20C2 Mkii Xm-l 720 Lumen Cree XM-L LED Flashlight, and after much research, including reading many reviews for a variety of 18650 batteries, I settled on four of these Ultrafires because of the overall customer rating and economical price.

The flashlight was bought primarily to serve my wife on her nightly walks with our Husky around our property (about .75 mile per lap). She wanted something compact, bright and dependable, and the flashlight did an amazing job... while the batteries lasted. The problem was that she would not even get two 20 minute walks on one charged battery, and would without fail have to replace the battery in the middle of the second night's walk.

I ended up replacing these pieces of junk with Panasonic NCR18650A cells which only need recharged after ten or more nights of use. I guess sometimes you really do get what you pay for.

Do yourself a favor and stay away from these batteries. The Panasonics TWO PROTECTED 3100mAh 18650-Industrial NCR18650A Panasonic Cell inside are great and Eagletac sells some on its website that are even better.
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15 of 19 people found the following review helpful
on December 14, 2011
Please be very careful when buying 18650 lithium ion batteries. MOST of the batteries coming out of China are Fake, Meaning they are recycled batteries with new wrappers put on them. 99% of people never actually test the capacity of these batteries and they think since the light goes on its a great battery. Ultrafire, Trustfire, and GTL (to name a few) are garbage and could actually be very unsafe. [...]
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6 of 7 people found the following review helpful
on July 28, 2012
After getting a couple of these in flashlights I bought here and seeing very poor battery life I was suspect about their capacity. I am an electrical engineer and I own a calibrated battery tester. I have tested LG and Panasonic cells in the past and in general they meet 95%-110% of their capacity ratings. However, when I tested these UltraFire 3000 mah cells they tested at 1550 mah on one, and 1610 mah on the other, or about 50% of their rating. This is consistent with the flashlight time tests done by another reviewer. This low capacity - about 50% of what is claimed - is typical of off/unknown brand Chinese cells such as these. I have seen similar results with other off brand batteries that I have tested.

A good 2800-3000 mah 18650 Li-ion cell is worth $8-10 retail (qty. 1). If you are getting these at two for $5, you should not be too surprised that the ratings are a joke and that they don't hold their charge for more than a few weeks (this is probably due to a poor quality protection PCB). If you want a battery that meets its ratings, stick with a known brand such as LG, Samsung, Panasonic, Sony, Tenergy.
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14 of 18 people found the following review helpful
on August 26, 2010
I received these batteries yesterday. Wanted to try them out, so I charged them and let them cool after charge and attemped to put them in my TK30. They did not fit. The diameter of the batteries was just oversized enough so they would not fit. I used the ultrafire charger as I have other 18650 batteries that work ok. Seems like this is a quality control issue for the 3000 mah battery.
Would not recommend buying these batteries.
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4 of 4 people found the following review helpful
on March 13, 2012
I received a pair of these cells included with a flashlight. After a couple charge cycles i tested them and was surprised to find the actual capacity less than half the claimed 3000mah.

With a modest 1 amp load I was only able to get about 1200mah out of these cells. I also estimate max discharge rate to be about 2.5amps.
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4 of 4 people found the following review helpful
on February 10, 2012
Batteries won't stay charged but about three days for 15 minutes per day. Poor, poor, poor. I have some
older batteries that are Blue that will stay charged that long. Dont buy these batteries.
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4 of 4 people found the following review helpful
on March 8, 2012
Generic packaging. Charges up to 4.2v and shuts off. The red charging led is more orange, and the green completed led is a little yellow. Other than that it is a good value. I would buy again.
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