they are the best for high power drain they win hands down over any other battery
Choosing between them isnât very difficult imo. If you have well regulated light Panasonics are for you, If regulation is not perfect (like with AMC based driver) Sanyos are better choice.
PS. Have you noticed that Fasttech doesnât have protected Sanyos UR18650FM? They just have UR18650Fs which are older and may have less capacity.
No, it hasnât. 3400s still are over $17, 3100s are over $14.
Are you sure? From what I have been reading in some other threads here, there is no real difference between F/FM? From what I can read the cells are also brand new and measure near 2600mAh Capacity?
What cells would you recommend in Single 18650 Nitecore Flashlights⌠Is 3400 oder 2600 the better choice? P25/EC25 for example. They both have step down after 20min. So running them only at turbo isnt a good choice at all
Great thread. But I confess, Iâm still a little confused 
Question:
What is the difference between these, is it just the wrapper and button vs flat top? There seems quite a price difference though?
and
Has anyone tested if the protection on those (Panasonics and Sanyos) that FastTech carries have also short protection over some Amp draw?
Chicken Drumstick,
Basically the batteries in the bottom link have a much wider button top at the top and the pcbâs are better. The pcbâs were probably done by a different company than the top battery link.
EC25 steps down after just 3 minutes. After that itâs pretty well regulated so it can squeeze more juice from Panasonics.
Doesnât this depend on the type of regulation it can perform? Along with how you use the light, if you turn it on for long periods then youâll get the step down, if however you use it for short burst you might not often get it to step down.
If the driver canât boost the voltage once the 18650 drops below the voltage required then itâll only dim with time rather than give a stable output.
In such a situation the 2600 may well offer higher voltage for longer than the 3400. If however you are likely to use lower output modes more often that donât require such voltage from the battery, then the 3400 will offer more overall runtime.
Can anyone give me a link to protected Sanyo UR18650FM batteries at Fasttech?
As mentioned above, there are two UR18650FM models but they seem to be unprotected.
The closest protected Sanyo 2600mAh is the UR18650F . Are they the same as the FMs?
I could be wrong but from the info I can find if they are 2600mAh they will be FM. The couple I have got from them measured up ok on my hobby charger.
Those are what I have ordered and received UR18650FMs.
As a newby I,m gunna jump on the end of this thread and ask if Iâve got this correct,
Panas,
18650= 2900
18650a 3100
18650b 3400
Correct??
And they all come in button top, flat, protected and not, is this correct??
Are these the âsafe 
â imr? People talk about.?
Sanyo,s
Whatâs the diff between the fm and the ztâs, just the mah?
Fm 2600?
Zt 2800?
Do they both âhold voltageâor just the ztâs?
Iâm buying a pair of each to upgrade the old tf flames, so
These panaâs https://www.fasttech.com/products/0/10001980/1141104-panasonic-ncr18650b-protected-rechargeable-3400mah
And these sanyoâs https://www.fasttech.com/products/1420/10001901/1143804-sanyo-ur18650zt-18650-2800mah-protected-rechargeab
Can someone please check that these are the protected button top variety.
Cheers n thanks.
Most prefer the Sanyo UR18650F 18650 2600mAh Protected Linky
Do a search for the 2600âs, lots of threads on this forum. You have the correct 3400 Panasonic batteries.
Here is one of many threads: 2800?
You chose wisely. Both button top, both protected.
IMR is a whole different animal for specific uses.
When I bought lime 6pairs of the Panasonic 18650 3400mah proteced batteries they were 19.01 q pair I can only speak on what I know they are pretty darn long and fat, and my own informal test with a Kaidomain C8xml2-u2 I got 2 hrs 17 minutes before the protection set in and shut it down.
How could you tell UR18650FM? The markings on the battery is illegible.
Hi BLF, sorry if this is considered as hijacking the thread. Hope it is okay to ask some 18650 related questions here 
Trying to choose some beginnerâs protected 18650 cells. Noticed the following in various posts and links, but have concerns primarily the âfittingâ of cell into different flashlights. Would you consider any particular of the following as âbeginner proofâ and âbest all-rounded fittingâ??
- Panasonic NCR18650B Protected 3400mAh
- Keeppower Protected 3400mAh
- ZebraLight 3100mAh
- any other good contenders?
By the way, currently donât own any 18650 flashlight, and have been dreaming over single 18650 lights such as SRT7, SC600 MKII, PD35, SRT5, ArmyTek, etc⌠Oh no!! I am in trouble, hahah!! Also, I have similar questions for 14500 choice here. Many thanks!
Depends on your flashlight. Most flashlights run better on 2600mAh based cells, because the three cells you posted can be discharged to a lower level.
Thank you NightCrawl. So if I understand it correctly, 2600mAh would indeed be the better âall-roundedâ cell choice for beginner? Guess I will have to eventually decide on the first 18650 light here, and then post the question again⌠
Yup. For an explanation, go there:
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
Select Keeppower 18650 2600mAh and Keeppower 18650 3400mAh. Then click the boxes to show only the 3A curve. You will now see two curves, thats the "voltage under load" curve, for a load of 3A, which is a good load for an XML light. An XML needs about 3.4V at 3A. Now if you take a look at where the cells reach 3.4V, thats at 2Ah for the 2600mAh cell and about 1.5Ah for the 3400mAh cell. That makes up for 25% more runtime on max output, but in total the light would run longer with the 3400mAh cell.
The difference is not that big and you'll be fine with either cell, but the 3400mAh are more expensive than those with 2600mAh. And, for a beginner, its advisable to stick with protected cells. Also, if you dont have a multimeter, get one. Cheap one for 10 bucks is fine. ;)