So far the only 18650's I have are a couple of TF flames, but I need a few more. Now I am wondering, should I stick with the TF flames, or should move to protected Panasonics or Sanyos? If the latter, why? Are they so much superior or ... ? And where should I buy them from? I noticed DX carries Panasonics and Sanyos but then again I supopse they might be fake?
taz, you have been around long enough to now the dangers……
my vote, go the Panasonic 3100 unprotected for a single cell light, I have the trustfire flames from DX and manafont and they are pretty good but the Panasonic deliver the amps when the led demands it.
sanyo protected cells (xtar 2600 etc) for the multi cells lights.
the Panasonics deliver higher current and can take a beating.
I bought my Panasonics in Australia so I can not recommend an international seller. (but this guy was great)
http://www.ebay.com.au/itm/280734814214?ssPageName=STRK:MEWNX:IT&\_trksid=p3984.m1497.l2649
there are Panasonic protected cells but I have not tried them.
Panasonic 3100 isn’t best choice for single-cell light, Sanyo 2600mAh is better for single-cell ones due to flatter voltage curve - they’ll maintain higher brightness for longer time.
For protected batteries, I’d recommend Keeppower brand for 3100mAh ones ($23/pair on eBay) and Intl-Outdoor Store brand (their protection PCB, and variance between cells, is way better than $2 cheaper Xtar’s) for 2600mAh ones ($17/pair on, duh, Intl-Outdoor Store).
For unprotected - Sanyo 2600mAh’s can be had for $11 a pair from Kaidomain: http://www.kaidomain.com/product/details.S009747 they’re genuine, no need to worry about that.
So unprotected is safe for single cell flashlight, or should I just stick with protected batteries regardess? $23 to $11 for a pair makes a big difference...
Unprotected is safe for single cell lights as long as you don’t leave them unattended. When light gets dim, you should turn it off and replace/recharge battery.
Better protected then, there are other people using the flashlights also who are unaware of such things!!! Is there anything cheaper but still good quality/value than the Keeppower you mentioned?
http://www.intl-outdoor.com/2-pcs-sanyo-ur18650fm-2600mah-protected-battery-p-516.html
This, cheaper per-mAh.
Digging this one up, bought couple of C8 clones from Ebay to use on my bicycle, my first Li powered lights :D!
The same question as OP - what are the best bang for the buck protected 18650 out there?
I want to stay within ~20$ shipped for pair or two pairs of good quality protected cells :)!
http://www.manafont.com/product_info.php/efest-sanyo-protected-18650-37v-2600mah-rechargeable-battery-pairset-p-11591
Those ones are quite good, $14/pair.
I would go with these: http://www.intl-outdoor.com/2-pcs-sanyo-ur18650fm-2600mah-protected-battery-p-516.html
Efest ones use same cell yet are $4.5 cheaper 
Thanks guys, that was quick :D!
Are there any good protected 3100 around?
I know protected 3400 are way overpriced, at leat those that Ive looked for at Ebay, 40$ for a piece, wtf 
Yeah, but protection circuit can still make a difference. I trust Efest with their IMR cells, but after the story with Himax, I would wait for a review..
http://www.intl-outdoor.com/2-pcs-panasonic-ncr18650a-3100mah-protected-battery-p-333.html
3400mAh cells are still pretty rare.
I would use a recognised seller if you go ebay route.These guys i have either used or know people that have .They have good feedback.
http://www.ebay.co.uk/itm/2x-Panasonic-IMR-CGR18650CH-10A-discharge-3-7v-18650-li-Ion-batteries-case-/290790282196?pt=UK_ConsumerElectronics_Batteries_SM&hash=item43b47393d4
I use these and find them v good.I also use ther charger and its been fine.Worth reading the full listing.Contains a good explination of safety stuff
http://www.ebay.co.uk/itm/2-x-XTAR-18650-3100mAh-3-7v-Li-ion-Protected-Rechargeable-Batteries-Panasonic-/180978034983?pt=UK_ConsumerElectronics_Batteries_SM&hash=item2a2321a927
Hope this helps you guys.
DON…
So far Shadowww’s Efest ones look like the best bang for the buck, dont feel like paying extra 11$ for additional 2x500mAh, Efest cost roughly 2.73$ per mAh, while those Panasonic 3100mAh’s cost around 3 4.18$ per mAh if my calculations are correct 
For that money I could just get 4 of those Efest batteries 
Can you go lower than that :D?!
Or are there any reliable battery vendors besides Intloutdoor and that Manafont link?
I know these questions have been answered many times here, but I wasnt quite interested in Li batteries before, so they havent got my attention till yet 
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
Chose Intl Outdoor 2600mAh and Spark 2600mAh. Thats the difference the PCB can make. Negligible up to 2A, but huge at 5A..
Keeppower 3100mAh are cheapest 3100mAh cells available, IIRC ($23/pair + $2 shipping, but eBay seller “doingoutdoor” accepts $20 offer).
This is exremly overpriced. I know the following companies, which have protected 3400mAh: Keeppower, Eagletac and Enerpower. HKJ tested the Keeppower and Enerpower. In Germany I can buy one of the Enerpower 3400mAh for 24€~$31,50 (within shipping):
http://www.amazon.de/Enerpower-3400-Li-Ion-Format-18650/dp/B00924UKGO
They use the HKJ diagramms.
NightCrawl, I don’t know how I’ve never seen this site before, it’s really informative! Thank you!
On a side note, I use a lot of the TrustFire 3000mAh Flame cells, and while comparing them to the others, I noticed the curves look incredibly similar to the Samsung 2800mAh cells. Coincidence?
Ok, Ive googled a bit and it looks like its possible to get 2x3400 protected for less than 25$, corret?
Thats still more expensive than 2600…