Test / Review: Panasonic NCR18650B 3400mAh (Green)

Panasonic NCR18650B 3400mAh (Green)

Official specifications:

  • Real capacity: NCR 3400mAh
  • Size: 18mmx65mm
  • Netweight: 45g
  • <=45mOhm
  • Cut off at 2.75V, full charge 4.35V (Wrong value)

This is the latest cells from Panasonic with the highest capacity.
The cell used can be discharged down to 2.5 volt, in my test I only discharges to 2.8 volt, i.e. I do not measure the full capacity. But then, not all lights will be able to use the full capacity.

These batteries are good at both low and higher current.

These are unprotected cell, i.e. the protection will not trip.


This is genuine Panasonic cells and cannot get any other rathing than very good, but remember that they are unprotected!

Notes and links

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries

Wow! That is pretty impressive. Thanks for another great test HKJ. :)

Been waiting to see this one. Thanks, HKJ!

Interesting this advance in technology.

Thanks very much for the excellent review! Frontpage’d and Sticky’d.

—-Cut off at 2.75V, full charge 4.35V

Full charge @ 4.2V
Keeppower 18650 3400mAh

CNQ @ 4.35V

So…… Full charge 4.35V or 4.2V ?

It is 4.2 volt for a full charge.

Thanks :bigsmile:

Your #0 post still 4.35V

That is a copy from the website, in the table I have the correct value.

I have edited the "Official specifications" to better show it.

Great as always HKJ, I will have to wait till my 2900’s and 3100’s begin to be tired, as I have more batteries than time haha.

FOI the generic PROTECTED ncr18650B 3400mAh are available from trusted dealers, see for example

HKE, ..

length is spec'ed as 70.5mm but i can hardly believe that. Such cells wouldnt fit in a grand variety of common popular 1x18650 flashlights or multi-18650 flashlights.

Anyway, they exist, and price is good too shipped. Let's recall that Protected Efest 3400 cost ~25 bucks shipped, button top version.

I have a batch of these cells from Ric and these are fantastic
in performance and quality.

I just got 2 of these from FastTech and they fit in the Sipik sk98 clone (a touch long but you can screw it shut) and they fit nicely in the Aleto 26650 version with the 18650 insert.

I got 2 pairs from FT that look exactly like those, and they measure right at 70mm with my cheapie caliper, so I’d say the spec is pretty close.


Just measured mine - 69.59mm

i guess its not a good thing to use this battery on a charger that only charges up to 4.2 v ? like the nitecore i4 ?


You have to use it on a 4.2 volt charger or risk problems.

The battery is full charged with 4,2V.

If you have other batteries like the Samsung ICR 18650 30A which is full charged with 4,35V - a 4,2V charger is not a problem and will not harm the battery. Of course it's not charged 100% full, but you can read in many thread, that a not 100% full charged battery will have a longer lifetime.

sorry i thought fully charged is somewhere between 4.2 and 4.35 hence the correction above.
thanks you. :slight_smile:


I would like to ask the difference Panasonic Protected and Unprotected batteries.

In protected batteries it had some kind protection for overcharge, over-discharge, etc…
and unprotected didn’t.

So… If I’m charging the protected batteries, it will stop if the batteries FULL. ( Green Light )
what about the unprotected one ? Is it the same ? My charger output DC = 4.2V

I’m gonna used it for some kind ultrafire XML-T6 flashlight is it OK ? After an hour using full brightness it’s very hot.