I use unprotected cells most of the time and they work great. some lights have connection problems because the unprotected cells are usually shorter though.
Maybe I'm overly cautious but I'd never run unprotected Li-Ion cells in series - period.
And I know this is BLF and not CPF but I'm having a hard time understanding why anyone would shell out the necessary for high quality, high output lights like the TN30 or BTU Shocker and then feed them with ****fires or laptop pulls.
Could be just me.........
Do you really need to buy all 20 right away?
I was wondering the same thing myself to be honest…
I don’t use unprotected cells myself, but I can see two reasons why people would want them.
- Higher currents
- Cheaper
For better cells, they do have higher currents because there is no protection circuit to trip. The Panasonic NCR18650PD protection circuit trips at 7A, which is still very high, but nowhere near the amps it can reach without a protection pcb. Unprotected, it can reach 15A. Not to mention protected NCR18650PDs are around $30 a pair, while unprotected are just $14 a pair.
Laptop pulls are not dangerous as long as one takes precaution and shows respect. Sure, they’re not fool-resistant like properly protected li-ions, but they are a good source for quality power. (I’m not saying that protected li-ions are fool proof though. :D)
I like it 
I initially wrote fool proof but realized that it wasn’t very accurate. 
- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- Douglas Adams in Mostly Harmless (1992)
I have TrustFire 3000mah batteries because based on most of the tests I've seen they perform similar to a Sanyo 2600mah battery.
I believe most of mine do but some are inconsistent. I also don't think they can handle 3+amp flashlights very well.
I really would like to order 20 of them because I like to have batteries in the lights I use frequently. I would realistically need about 30 including my EDC, P60s, and C8 sized lights. However, most of those lights wouldn't benefit from a 10a battery.
How much are you buying these for?
Because the Panasonic NCR18650As are 3100mAh at $14 a pair, probably cheaper if you buy 10 pairs.
$12.71 per pair for 5 or more pairs at Fasttech
Oh, the price has come down then. Maybe I’ll buy a few more…
EDIT: you linked the unprotected batteries. For protected batteries it’s $1 more: http://www.fasttech.com/products/1420/10001980/1141103
The only thing I am afraid of with all of the Fasttech protected batteries is the additional clear casing making them too large in diameter.
Or is that common amongst all brands and I am just noticing it because the casing is clear?
Very true, cuz that's what the OP seemed to be looking for. 
>>>>>high output lights like the TN30 or BTU Shocker and then feed them with **fires or laptop pulls.
New is new whether you get them from fasttech or pull them from a NEW power pack.
And they’re essentially half what Fasttech charges.
I’m not saying FT’s 2900s are fake, but who really knows about other vendors. With all the fake battery labels floating around, really the only way you can be 1000% sure of whether a battery is real — Get it from a name-brand battery pack! No way a company like Acer will use anything but real Panasonic batteries.
But I wholeheartedly agree about the TF flames. Why buy something iffy when you can buy a name-brand quality battery for a few bucks more?
Of course, the protection circuits in any of these batteries are made by who-knows in a tin shack somewhere in China. Considering the quality-control level of all things Chinese, I sure wouldn’t bet those circuits will work as designed in an emergency situation. But since they are the only thing available, I use them in multi-cell situations in both series and parallel setups. I have ’em, so I might as well use them. Have I used unprotected cells in parallel lights? Sure. But not on a regular basis. I ALWAYS use protecteds in series lights, but since I only have a couple series lights, I don’t do it much.
I am one of the few who actually had a 14500 ultrafire KAPOW while charging, so I don’t use ANY Chinese *fire batteries. Don’t need to. Have like 300 batteries (almost all pack pulls)! Which reminds me, I think it’s getting to be time for another battery giveaway!!!
Quite true.
However given the large number of posts at BLF describing how people scrounge for discarded laptop packs this was the first thing that came to my mind when the term "laptop pulls" was mentioned.
You seem to have had good success with your method. Have you ever had problems with old stock that may have been produced years ago? I guess for under $2 per cell it's not a big deal but AFAIK they can deteriorate even in storage.
I use the same approach as Ubehebe. I also buy cells for Fasttech and other reputable vendors when I need special or protected cells.
All the Li-ion cells I have acquired using Ubehebe’s approach been excellent so far. You have to get an OEM pack, like Ubehebe’s example, and measure, measure, measure for a bit just to make sure you have solid cells. There was an excellent discussion and testing in a thread that Ohaya started. Here is a link to that thread and a subsequent one.
I have had terrible luck though trying to get 4/3F Ni-mh cells this way though.
I have the Skyray King and I used cheap unprotecteds for a while at first (until switching to Tenergy 2600s Protected). Only negative thing with the former was short runtime, but never any troubles. Since its a regulated driver, output was the same. But as long as they are not in a series, it doesn’t matter. Unprotecteds give a touch better output in most of my lights.
It is not very common. I think Fasttech does it to show they are using authentic cells. I have protected Panasonic NCR18650B’s, protected Sanyo UR18650FM’s, and protected Sanyo UR18650ZT’s all from Fasttech with the clear wrapping. They are definitely slightly wider than a an unprotected version of the same cell, however, out of all the flashlights I own (see signature), the only light they have not fit in is my DQG 18650 from CNQG. The only cells I have (see signature) that fit that light are Trustfire protected flames, due to the light having a very narrow battery tube. My only issue with the Fasttech protected cells from a quality standpoint is that their protection circuits are pretty chintzy. They get bent inwards easily and just seem to be very cheaply made and flimsy.
If you look at the batteries page of my signature, I measure all of my batteries with a digital caliper and you can see the differences in length and width. I think you will find the Fasttech protected cells are minimally wider. The bigger concern is the size of their protection circuit. It is fairly tall and combined with their button tops, they make for the longest batteries I own. Again, this has not been an issue with *ANY*of my lights, save for the DQG 18650, but it does make for a snug fit in some of my lights with battery carriers.
I have all of the lights you mentioned, save for the Fenix TK75, and the Fasttech protected cells fit all of them with no problems.
Personally, I will only buy Redilast 3400’s from Jason at EDC+ (he owns the Redilast brand) now because he is so anal about quality control, having the highest quality proprietary protection circuits, and hand testing all of his batteries before shipping them. They cost more, but peace of mind is important to me when carrying around something that has the same explosive force as an equivalent amount of TNT in my pocket.
If I were to not buy Redilast 3400’s, I would probably buy Keeppower 3400’s from Doingoutdoor.com for $22.99 a pair. That is a good price for a premium 3400. Fasttech also has re-wrapped 3100’s with higher quality protection circuits and better button tops for $16.86 a pair. I think those would be worth the extra $2 a pair over the Fasttech clear wrapped ones.
>>>>>Have you ever had problems with old stock that may have
>>>>>>been produced years ago? I guess for under $2 per cell it’s
>>>>>>>not a big deal but AFAIK they can deteriorate even in storage.
Old stock … I don’t buy that much, so I’m really not concerned whether it’s two days old or 4 years old. (Although I did buy about 30 of those new Panasonic 2900s when the packs were going for like 8 bucks or so.)
If it’s crapola, I just toss it. My investment: maybe 15 minutes per pack, plus I REALLY enjoy the whole battery hunt and pack-disassembly thing.
Hunting for batteries to me is like looking for gold. Sometimes you get a bunch of rocks; other times you get gold. But if you don’t look, you’ll always get nothing. 
But I also realize, that recycle-bin diving and cracking packs isn’t for everyone.