I just ordered two XM-L T6 flashlights, now I thinking of getting four 18650 batteries for use with them.
Currently looking at Trustfire 18650 3000mAh.
Do these get good feed back? or should I being at another brand?
If you want protected cells, check out the batteries recommended by Dru_dragon in post #3 of the following thread:
https://budgetlightforum.com/t/-/30388
I would buy them if I needed some 18650's.
No! Don’t buy any batteries with Fire in the name. That means no UltraFire, TrustFire, SuperFire, SureFire, UranusFire… They’re just bad news.
”
Who knows what could be inside!“:Have you seen this type of counterfeit 18650 battery before? UltraFire
Pick up some real brand name batteries, eg Samsung, Panasonic, LG, Sony, etc.
Bought some Keeppower 26650, 18650, 14500.
Guess I see how well they work.
Also been buying used laptop pulls (Samsung 18650 2600mAh), so far they will still hold almost the same capacity as when they were new.
Keeppowers are great as well, I believe they’re Panasonic cells with Keeppower’s protection circuit.
And laptop pulls are good too, so long as you’re careful with them until you know they’re safe. I’ve pulled apart over 10 laptop packs with less than 10% DOA rate. Mostly New-Old-Stock packs.
Although a 2011 thread there is some excellent info on 18650 batteries.
http://lygte-info.dk/info/Batteries18650-2011%20UK.html
While not the best the Trustfire did not show up too badly. However, it is not the most desirable. Take a look.
I have four Trustfire 3,000 mah batteries, and although I don’t use 18650 lights often those batteries have given me nothing to complain about. I have other brands I bought from FastTech. I am not sure about the shipping problem now.
http://www.fasttech.com/search?Panasonic
Without a doubt the Panasonics and other standard Japan batteries are superior to Trustfire in my view.
Jerry
Be Very careful with Keeppower, as some of their batteries use chinese cells, while others use Japanese & Korean cells (the same applies to the protection circuit/IC)....
If the label says Cell Japan or Korea, & IC Japan then both cell & protection should be OK...
If the label says nothing (as in the case of Keepower batteries sold by some vendors), then BEWARE!!
Caveat Emptor.
Best Regards,
George
My 14500 lists IC made in Japan and assembled in China.
My 26550 and 18650 do not list IC or place of manufacture.
Just checked the sellers website, for the 26550, I would have had to pay $2 more per battery, for the protected ones with the Japan IC
With the 18650, I would have had to pay $4 more battery for the protected 18650 with Japan IC and assembled in Japan.
I’m learning.
Wow. Learn something new every time I come here.
I personally don’t have any Keeppower batteries but I’ll keep that in mind.
Just genuine AW IMRs, Orbtronic 3400, and a buttload of laptop pulls 
I read that used lap top cells typically have 60 to 70 % capacity left.
I’ve bought 14 Samsung 18650 26A (used laptop) batteries.
First time charging the batteries (at 500A) the capacity maxes from 1500mAh to 1900mAh.
But if I do a discharge/recharger at 200A, they improve to around 2000mAh to 2250mAh.
They might even improve at even more(?) with a few more 200a discharge/recharge.
OM! I already ordered 2 batteries with *fire in the name… Ultrafire or maybe Trustfire, I could not remember but definitely some “fire”.
There are so many brands called “fires” that a layman like me can hardly get them straight.
Wait…Isn’t Surefire the really reliable one?
If you aren’t going to modify them to be higher than stock output…good daily driver batteries [
GP-General Purpose] w/ adequate performance to price ratio…get laptop pulls Sanyo or whatever, there are several people here that sell good laptop pulls for a very nominal price (usually lower than those **fire batteries as well)
I don’t actually know, maybe someone else can chime in on them.
I just stay far away from anything *Fire after having a cheapo ultrafire that came with a flashlight I bought. Turns out it contained a teeny tiny battery and was packed with powdery stuff like cement mix. 
{21 guns wrote:
OM! I already ordered 2 batteries with *fire in the name… Ultrafire or maybe Trustfire, I could not remember but definitely some “fire”.
There are so many brands called “fires” that a layman like me can hardly get them straight.
Wait…Isn’t Surefire the really reliable one?}
I have some Surefire batteries without any problem. I prefer Panasonic if available, but there seems to be some terrible fear of XXXFIRE brands. I have some 18650 Trustfire batteries and have for maybe 5-7 years. I have had no reason for criticism. Again, I would prefer other brands as have been mentioned, but no need to panic, although the name “fire” seems to panic some here, just use them.
Jerry
I have 12 of the old 2400mAh TrustFire Flame-ones.
They were pretty good for a period of time.
But today, I prefer the 4 pack of 2600mAh Samsungs “raccoon city” linked in the first answer.
Cheap, good, protected.
I aldo have 4 Panasonic 3400mAh protected - but they are too expensive and give me not that much more than the samsungs (I have 14 of the Samsungs now… sheesh… 12 TrustFires, 14 Samsungs, 4 Panas, 3 Laptop Pulls… not enough yet :D)
Stick to protected cells.
Samsung, Sanyo and Panasonic. These will give you the best run-time.
I posted a thread asking where to buy these before but I ended up finding some deals on DX.
The deals are dead however so I guess do some googling which sites offer those 18650s for a good deal.
Convoy have recently started to sell quality cells.I have not ordered yet but their reputation and prices are good.
typical.
cells with increased internal resistance act like that.they dont actually improve they just do better at a lower rate.
i assume you mean 500ma?
my standard test for an 18650 is at 1a (1000ma)
good capacity there means its useful.
yours may be tired.may not matter if you are using them in a low drain item.i save cells with decent capacity at low rates for all those cheap direct drive 9aaa lights.
increases both their usability and disposeability.ie who cares if lost,stolen,dropped overboard,ect.
When shopping for batteries of various form factors, you may want to consult the “Battery Comparison Guide” available here:
You can click the @ sign in the Review column across from each battery and follow the link to a page with the test results, the picture of the battery, what types of cells are inside, what dimensions the battery is (you can use this to determine if it will fit into your flashlight), and the conclusion on the bottom of the page which will tell you if this is a good battery or not.
When shopping for battery pulls (batteries extracted from laptop battery packs), you may want to use the “BLF Community Battery Pulls Overview Thread” available here:
It will tell you what type of cells and capacities of batteries are inside a specific laptop battery pack. Clicking the Post link in the Link To Post column will take you to a post in which a BLF member shares his/her experience with that particular laptop battery pack and shows in pictures what it looks like.
I hope you will find these resources useful.