# Test/Review of Panasonic NCR18650B Protected 3400mAh (Green)



## HKJ (Jan 21, 2013)

[size=+3]Panasonic NCR18650B Protected 3400mAh (Green)[/size]







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.








[size=+3]Conclusion[/size]

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



[size=+3]Notes and links[/size]

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


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## space-cowboy (Jan 21, 2013)

Good review like always.

Possible issues:

1.Who is the company that put this assemly together?
As I know there are at least 5-6 different Chinese no-name manufacturers. So keep in mind that when buying no-name cell you might end up with 3A cutoff as well.

2. It is not issue with the length only, 
it is the possible big issue with diameter as well. Manufacturer did not remove Panasonic green shell which makes the cell significantly larger in diameter /after installation of kapton tape, sense wire, and heat shrink.


Safety issue: Translucent kind of heat shrink (shrink wrap) is easy to split at higher temp. and expose sense wire - making high posibilities for short circuit. Especially on places near top, and bottom where sense wire is bent.


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## HKJ (Jan 22, 2013)

space-cowboy said:


> 1.Who is the company that put this assemly together?
> As I know there are at least 5-6 different Chinese no-name manufacturers. So keep in mind that when buying no-name cell you might end up with 3A cutoff as well.



That is always a problem, products can always change, especially when they do not have a named manufacturer. 




space-cowboy said:


> 2. It is not issue with the length only,
> it is the possible big issue with diameter as well. Manufacturer did not remove Panasonic green shell which makes the cell significantly larger in diameter /after installation of kapton tape, sense wire, and heat shrink.



This battery is not the only battery with two layers of wrap, many batteries has it.



space-cowboy said:


> Safety issue: Translucent kind of heat shrink (shrink wrap) is easy to split at higher temp. and expose sense wire - making high posibilities for short circuit. Especially on places near top, and bottom where sense wire is bent.



I am not sure if this is a real problem, batteries are usual not that hot and I have seen the black heat shrink split without high temperature.


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## Changchung (Jan 22, 2013)

Thanks HKJ for this review. Who send you this?


Sent from my phone with camera with flash and internet on it...


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## HKJ (Jan 22, 2013)

Changchung said:


> Thanks HKJ for this review. Who send you this?



Nobody, I bought it myself from HKEquipment.


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## space-cowboy (Jan 22, 2013)

HKJ,


It is important for USA CPF members to address potential issues, so I did it. 


Once US customer orders li-ion batteries from China, there is no way to return it via USPS (there are very expensive UPS, DHL, and Fedex options).

It is good to know.


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## Changchung (Jan 23, 2013)

HKJ said:


> Nobody, I bought it myself from HKEquipment.



Thanks, I think this was from fasttech, this one I think are BIGGER...


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## candle lamp (Jan 24, 2013)

Excellent test review as always. HKJ! :thumbsup:
Thanks a lot for your hard work. :thanks:
The length is really long!


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## HKJ (Jan 24, 2013)

I must admit that the primary reason I bought this battery, to test, was due to the length.


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## AbnInfantry (Jan 24, 2013)

I bought some of these batteries from FastTech. I haven't had any problem due to their length, but their diameter is so large they barely fit into some of my flashlights designed to use 18650 batteries. EagleTac brand batteries using the same Panasonic cell easily fit inside all these flashlights; unfortunately, they also cost twice as much.


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## HKJ (Jan 24, 2013)

AbnInfantry said:


> I bought some of these batteries from FastTech. I haven't had any problem due to their length, but their diameter is so large they barely fit into some of my flashlights designed to use 18650 batteries.



Looking at the photo at FastTech, they do not look the same, the top is another shape.


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## AbnInfantry (Jan 24, 2013)

HKJ said:


> Looking at the photo at FastTech, they do not look the same, the top is another shape.



I just checked and the Panasonic NCR18650B Protected 3400 mAh batteries I bought from FastTech look identical to the ones in your picture.


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## Changchung (Jan 24, 2013)

AbnInfantry said:


> I just checked and the Panasonic NCR18650B Protected 3400 mAh batteries I bought from FastTech look identical to the ones in your picture.



It is not the same...


Sent from my phone with camera with flash and internet on it...


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## Changchung (Jan 24, 2013)

HKJ said:


> I must admit that the primary reason I bought this battery, to test, was due to the length.



70,3cm it is bigger...


Sent from my phone with camera with flash and internet on it...


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## Bucur (Jan 28, 2013)

Excellent review HKJ! Thank you so much for the time and effort you have put into this review. 

I am using EagleTac 3400 mAh protected 18650 cells in my Nitecore TM15. No size problem: They fit nicely. May I assume that my cells are based on the ones you have reviewed so that your review is more or less relevant for my cells as well? Or, would this assumption be too good to be true? 

If my assumption is not too optimistic, may I also ask the following: 

- I am keeping my TM15 with fully charged batteries, in my car. The car is garaged. Even if the garage is not heated, it does not get below about 10˚C (a dehumidifier is on all the time and this seems to keep the garage a bit warmer than it would otherwise be). In summer, I don't park the car under direct sunlight often but this happens from time to time, albeit not for longer than a few hours at a time. I mean, not all day long. Would you foresee any heat related issue for the batteries? 

- I think exercising the batteries (discharging and charging them) from time to time would not be a bad idea. Is this correct? If so, how often? 

- I am considering discharging them by running the TM15 at high (not turbo), in front of a fan, until the voltage indicator flashes (batteries about 50% full), then, recharging. Would this be a good idea or would you recommend refraining from this and/or doing something else?


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## HKJ (Jan 28, 2013)

Bucur said:


> I am using EagleTac 3400 mAh protected 18650 cells in my Nitecore TM15. No size problem: They fit nicely. May I assume that my cells are based on the ones you have reviewed so that your review is more or less relevant for my cells as well? Or, would this assumption be too good to be true?



The performance is just about equal, you can find the review here.

To compare performance of different batteries, my comparator is very useful.




Bucur said:


> - I am keeping my TM15 with fully charged batteries, in my car. The car is garaged. Even if the garage is not heated, it does not get below about 10˚C (a dehumidifier is on all the time and this seems to keep the garage a bit warmer than it would otherwise be). In summer, I don't park the car under direct sunlight often but this happens from time to time, albeit not for longer than a few hours at a time. I mean, not all day long. Would you foresee any heat related issue for the batteries?




It will reduce the lifetime slightly of the batteries, especially if the temperature gets above 40˚C





Bucur said:


> - I think exercising the batteries (discharging and charging them) from time to time would not be a bad idea. Is this correct? If so, how often?


 

With LiIon batteries the only thing cycling them will do is wearing them out.
LiIon batteries is usual rated for 300-500 cycles, i.e. doing a few extra cycles each year will not really be significant for their lifetime.





Bucur said:


> - I am considering discharging them by running the TM15 at high (not turbo), in front of a fan, until the voltage indicator flashes (batteries about 50% full), then, recharging. Would this be a good idea or would you recommend refraining from this and/or doing something else?



That would also heat the batteries and increase the wear. If you want to cycle the batteries, get a hobby charger (They start at about $25), this way you can also check their capacity and see when to replace them.


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## LucidAce (Jan 28, 2013)

Thanks for the review HKJ. It's actually your tests that brought me to this forum.


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## Bucur (Jan 29, 2013)

Thank you so much for replying all my questions. Also thanks for the links to your website. This is an amazing place! Congratulations!! It seems I will spend quite some time there. There are so many things I would like to read… :thumbsup:

I have used a variety of hobby chargers for R/C cars in the past but I don’t have any, at the moment. I will gladly stick to your advice for my flashlight batteries as well. However, I need to understand how to use them for multiple but independent cells, first. I have noticed a chapter on this subject in your website, at a fast glance. I will read it at the earliest opportunity. I wish I could do so now but work calls on and I have to quit for now. 

Thanks again for the invaluable (and apparently unlimited oo: ) info.


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## space-cowboy (Jan 30, 2013)

AbnInfantry said:


> I bought some of these batteries from FastTech. I haven't had any problem due to their length, but their diameter is so large they barely fit into some of my flashlights designed to use 18650 batteries. EagleTac brand batteries using the same Panasonic cell easily fit inside all these flashlights; unfortunately, they also cost twice as much.




That is the exact problem that I was trying to address.


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## VidPro (Jan 30, 2013)

space-cowboy said:


> That is the exact problem that I was trying to address.



If you had Nothing to lose, meaning there is no way you could use them, and cannot send them back, and do not want to remove the internal cell , completly ruining the idea that it is protected.
You could attempt to re-wrap them. 
Someone mentioned that the clear heat shrink is thicker (not verified) , some of the clear battery wraps i have used here are thicker. that is a good thing usually. The normal stuff that you buy has a higher tensile and thinner, it breaks easier.
Get a tight fitting thin battery shrink wrap, and attempt to "fix" them. Tight fitting, because the diameter shrinks ~40% and gets thicker by that same ammount as it shrinks.

Using a xacto knife , you get under ONLY the first skin, the outer layer with the sharp side of the blade ready to cut the top skin, and the dull side against the cell, and rip the edge some, then peel.
Then re-wrap it, Trying to keep everything aligned, and stuffing the cell in a wrap that is flat and tight (its a pain). Then hit it with a heat gun carefully, to shrink it. I am not going to tell how to do it over a gas stove  and a hair dryer wont pull it off.
You wouldn't remove anything but the top layer, even though tempted, the original label is needed to keep the protection wire strip well insulated. 
I am guessing it would be enough pico meters  to fix it. 

That is the only thing i could come up with, unless they truely are different cells, or different batch, or factory, with almost identical properties as tested by HKJ The other cells likely have the same inner panasonic original wrap under them.

untill someone does, it is only a guess. Then we will need that one person (like me) to short the protection, and make a u-tube on how to replace $3 magnesium fire starters with $15 batteries


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## Changchung (Jan 30, 2013)

VidPro said:


> If you had Nothing to lose, meaning there is no way you could use them, and cannot send them back, and do not want to remove the internal cell , completly ruining the idea that it is protected.
> You could attempt to re-wrap them.
> Someone mentioned that the clear heat shrink is thicker (not verified) , some of the clear battery wraps i have used here are thicker. that is a good thing usually. The normal stuff that you buy has a higher tensile and thinner, it breaks easier.
> Get a tight fitting thin battery shrink wrap, and attempt to "fix" them. Tight fitting, because the diameter shrinks ~40% and gets thicker by that same ammount as it shrinks.
> ...



I was thinking the same, some time ago I buy in ebay from a USA seller some clear shrink wrap that I compare with some that I ready had and with what I replace with this and it is thin, but what a bought is not the size for 18650, ad it is like fragile, if you apply to much eat get broken...


Sent from my phone with camera with flash and internet on it...


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## VidPro (Jan 30, 2013)

If it was the conductor strip itself, that could be easily measured. Some of the protection strips are good copper, and very thin, wider, like a ribbon cable. this one might be more old style changing the diameter more.


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## Changchung (Jan 31, 2013)

AbnInfantry said:


> I bought some of these batteries from FastTech. I haven't had any problem due to their length, but their diameter is so large they barely fit into some of my flashlights designed to use 18650 batteries. EagleTac brand batteries using the same Panasonic cell easily fit inside all these flashlights; unfortunately, they also cost twice as much.





space-cowboy said:


> That is the exact problem that I was trying to address.



I bought a pair from fasttech too and a pair of intloutdoor 3400 and both are fat, barely fit in my lights too. I am thinking in stop to buy protected, if the light are good the driver can help to no overdischarge the battery, and using a realiable charger we have no problem with overcharging them...

BTW, this model of green batt is not the same that the fasttech had...


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## caall99 (Nov 21, 2013)

What is the maximum discharge current on the protected version of these cells? I know the unprotected ones have done 6A+. Can i expect something close to that on the protected version without triggering the PCB to shut the battery down?


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## HKJ (Nov 21, 2013)

caall99 said:


> What is the maximum discharge current on the protected version of these cells? I know the unprotected ones have done 6A+. Can i expect something close to that on the protected version without triggering the PCB to shut the battery down?



This depends on brand.
Check the "Protection test" and expect about 1A less for continues usage.


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## caall99 (Nov 21, 2013)

I am a little confused by what you are saying. Is maximum current draw before tripping the protection PCB 6.7A on the protected version? And is the non-protected capable of 1A more than 6.7A, so about 7.7A?

Also, why do the discharge curves look better for the non-protected vs. the protected on your comparator? I thought the protection PCB only effects voltage cut-offs (over charge and over discharge) as well as max current.

information here:
http://lygte-info.dk/review/batteries2012/Panasonic NCR18650B Protected 3400mAh (Green) UK.html

thanks for all the hard work you have put into this!!


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## HKJ (Nov 21, 2013)

You can get protected NCR18650B that can deliver more than 12A, depending on the brand of protection, you can also get some where the protection trips at a few A.

The cell without protection can, of course, also deliver more than 12A, but with or without protection, a high current will reduce the lifetime of the battery.

My curve shows how much current the battery can deliver for a short time, the continuous current is lower than that, as a rule of thumb, expect 1A lower. 

A protection circuit adds a small resistance in series with the cell, this often has 0.1 volt drop at the current where the protection trips, this means that protection batteries will have slightly lower voltage at high currents.


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## caall99 (Nov 21, 2013)

Thanks again! That answers my question.

Now, the important follow-on question. How do i know i am buying high current PCB protected cells? Many vendors do not state max current draw with the protection PCB. For instance Fasttech has some relatively cheap NCR18650B cells that are protected, but they are useless to me if the protection trips at low currents. I do want protection, as the light these are going into has zero protection built into the driver.


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## HKJ (Nov 21, 2013)

caall99 said:


> Now, the important follow-on question. How do i know i am buying high current PCB protected cells? Many vendors do not state max current draw with the protection PCB. For instance Fasttech has some relatively cheap NCR18650B cells that are protected, but they are useless to me if the protection trips at low currents. I do want protection, as the light these are going into has zero protection built into the driver.



Either from my reviews*, or by doing the test yourself with a hobby charger or electronic load.

*Dealers may have changed the protection pcb after the review, i.e. the protection limit can have changed.


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## caall99 (Nov 21, 2013)

Sounds like trial and error then. I will go ahead and order and perform some testing when i receive them. 

I also spent a lot of time on your website today. REALLY amazing stuff! Thank you for sharing with the community!


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