Test / Review: Panasonic NCR18650B Protected 3400mAh (Green)

Panasonic NCR18650B Protected 3400mAh (Green)

Official specifications:

  • Original Panasonic (Industrial) products, Made in Japan
  • Capacity: 3400mAh (Min 3250mAh)
  • Charging volt: 4.2v
  • Max charge current 0.7C 2A
  • Recommend discharge current 1C 2.9A
  • Discharge Termination Voltage: 2.5V
  • Protection kicks in : 2.75v and 4.2v
  • Over-Charging / Draining at 4.2v / 2.75v
  • Protection Circuit installed
  • Weight : 47g
  • Size 18.50mm x 70.5mm (Larger than non-protected)
  • The voltage of full charge & empty condition is 4.2v & 2.75v respectively

The above specifications is from the dealers website and there is a few errors in it!

This battery is not made by Panasonic. The cell inside the battery is from Panasonic, the protection cirucit and the assembly work is done by somebody else.
Notice the length of the battery, it is the longest 18650 I have seen to date.

The capacity looks very good as expected for a Panasonic 3400 mAh battery.

The protection at 6.5A makes it very difficult to overload these batteries, but is high enough for any normal use.


This is a very good battery, except for the length. Only buy it if you know you equipment can use a very long battery!

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

thank you very much, as always, for these very useful information

Thanks you very much!!

There are many products of Protected NCR18650B on the market! How many do we know? Enerdan, KeepPower, Eagletac, XTAR, Efest, ..

Yes, but they are not sold with that name on them and there is also small differences between the batteries.

Thank you for conducting your tests and sharing your findings.

I just compared some of the -B cells in HKJs comparator and it seems that - so far - the AmpMax and Keeppower perform best. Probably both made by Keeppower. Just like the one from Intl-Outdoor, but it doesnt perform as good. I wonder why that is..

Oh, and do you have a bare -PD cell up for tests?

Me too, I do not get the same result.

Generally there are two differences:

Capacity, this can be due to age of the cell. I.e. do I get a fresh battery and test it immediately when I receive it, or is it a couple of month old before it is tested.

Voltage at high load, this often depends on the protection circuit. I.e. a 12A protection will often have higher output voltage than a 5A protection.

There can also be production tolerances between different batches of cells.

No, but I expect to receive another protected one and will probably test it up to 10A.

Or Keeppower saves the premium circuit for the premium brands and the little less (but still very) good ones for budget brands like IO.

I guess you are gonna receive the one from IO? A comparison with the unprotected one would be really cool though.

That theory does not fit.

I will call the performance of these two batteries virtual identical.

The lowest trace (i.e. the 5A) is the best to see differences in protection.

Yes, the 5A trace is different but the capacity is the same. So that would be a different PCB. Why doesnt my theory fit then?

The 5A track is the same for the two batteries, except at the start and that has nothing to do with the protection.

Okay. So there is a difference in the cell?

That dip at the start might be due to temperature (The cell need to heat up a bit, to get full performance), my testing lab does not have a tightly controlled temperature, it will vary a few degrees.

Thats plausible. Thanks for enlightening me. :)

Thank you for conducting your tests and sharing your findings.

Thanks very much! Frontpage’d and Sticky’d.

Where can I get these batteries??

HKJ posted in his graph.

HKEquipment :wink:

HKJ, will these fit in the TN30 & TN31? Thanks.

Any known fav lights that these positively won’t fit in? I know Hi-Max’s won’t fit in 501Bs, but I’ve not seen too many batteries that are so big that they don’t work in most lights.