# Test/Review of Keeppower 18650 3400mAh (Black)



## HKJ (Jul 23, 2012)

[SIZE=+3]Keeppower 18650 3400mAh (Black)[/SIZE]







Official specifications:

18650 3400mAh Protected Rechargeable Battery 
Cell: Panasonic NCR18650B 3400mAh 
Min Capacity: 3250mAh 
Typical Capacity: 3400mAh 
Normal Voltage: 3.6V 
Quality Lithium Ion rechargeable cell 
In Built Safety Circuitry 
Protection Circuit (Against overcharge, over discharge, over current and short-circuit.) 
4.2 volts max voltage and 3.6 volts nominal voltage 






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.

































[SIZE=+3]Conclusion[/SIZE]

This battery has higher capacity and better high current capacity than its predecessor (3100mAh/NCR18650A).
With the added protection from Keeppower it is a very good battery.



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

Keeppower is a OEM manufacturer, i.e. many of the batteries they produce is sold with other names on them.

The batteries was supplied by Keeppower for review.

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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## HighlanderNorth (Jul 24, 2012)

What would be(if any) potential disadvantage or downside to using a battery with this much capacity in an LED flashlight, or in any other device? I would assume that if there was an over-discharge or short circuit it would potentially be more dangerous due to the higher energy capacity, but is there any higher risk of that happening with a high capacity battery vs. a 2200, 2600, 2900 mah battery?

Are there any other potential disadvantages of using a really high cap battery vs a lower cap battery?

At the bottom of the review, it states that Keeppower is an OEM manufacturer, and that other companies may sell Keeppower products relabeled with their own names on them. It also states that the cell is a Panasonic cell, and so obviously that Panasonic cell is being wrapped and relabeled as a Keepower product, so are you saying that some of these batteries like this one can be twice relabeled? The first company(Keepower) buys the Panasonic cells, adds protection circuitry, and positive terminals, then wraps these batteries in their own label, but then yet another company buys the cell from Keepower, and relabels it again? Why wouldnt they just buy a base Panasonic cell and put their own label on it, thereby skipping the unnecessary middleman?

Lastly, I googled this battery, and I assume this is very new, so the only sales results I was able to find were a few companies selling them in quantities of at least 100 batteries, but no listed price. Is it just too early yet, and stores havent gotten them in, or is this one of those situations where they are only going to be sold in bulk? Any idea how much they are charging for 100 of them?

Lots of questions^, sorry about the deluge.......


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## HKJ (Jul 24, 2012)

The protection PCB prevents some dangers and Panasonic has also build the cell as safe as possible.
The danger from the battery is more depend on the battery construction, that on the actual capacity, i.e. a 1000mAh xxxxFire is more dangerous than any Panasonic.

I cannot see any disadvantages from a large capacity, there might be other disadvantages, not directly related to capacity, like: battery size, battery voltage, maximum current.


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## tobrien (Jul 24, 2012)

i hope the same guy on eBay starts selling these!

thanks HKJ!


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## HighlanderNorth (Jul 24, 2012)

tobrien said:


> i hope the same guy on eBay starts selling these!
> 
> thanks HKJ!




Was there a guy on Ebay selling other hard to find batteries? Lets guess at how much these will cost when they hit the stores(if they ever hit the stores in non-bulk quantities)..... Since the relabeled Chinese 3100mah Panasonics seem to sell for around $15 -$16, I'd say these should go for $17.50..


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## RedForest UK (Jul 24, 2012)

HighlanderNorth said:


> At the bottom of the review, it states that Keeppower is an OEM manufacturer, and that other companies may sell Keeppower products relabeled with their own names on them. It also states that the cell is a Panasonic cell, and so obviously that Panasonic cell is being wrapped and relabeled as a Keepower product, so are you saying that some of these batteries like this one can be twice relabeled? The first company(Keepower) buys the Panasonic cells, adds protection circuitry, and positive terminals, then wraps these batteries in their own label, but then yet another company buys the cell from Keepower, and relabels it again? Why wouldnt they just buy a base Panasonic cell and put their own label on it, thereby skipping the unnecessary middleman?



W/regards safety HKJ covered it, the safety characteristics of a cell are not really dependent on capacity, but on the quality of construction and effectiveness of the PCM. Panasonic cells are incredibly safe for li-ion and keeppower uses top quality SEIKO PCMs.


OEM means that other companies can contact keeppower and keeppower will simply print a different design on the label or send them without a label for the company to apply their own. There is no extra layer of wrapping, but other companies may charge significantly more for the same cell as keeppower provide with their own branding.


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## HKJ (Jul 24, 2012)

HighlanderNorth said:


> At the bottom of the review, it states that Keeppower is an OEM manufacturer, and that other companies may sell Keeppower products relabeled with their own names on them. It also states that the cell is a Panasonic cell, and so obviously that Panasonic cell is being wrapped and relabeled as a Keepower product, so are you saying that some of these batteries like this one can be twice relabeled? The first company(Keepower) buys the Panasonic cells, adds protection circuitry, and positive terminals, then wraps these batteries in their own label, but then yet another company buys the cell from Keepower, and relabels it again? Why wouldnt they just buy a base Panasonic cell and put their own label on it, thereby skipping the unnecessary middleman?



Sorry that I forgot to answer that question.

For any protected battery a company must add the protection circuit, rewrap the cell and add a label, as OEM Keeppower will do that for other companies.

I.e. if you want to sell a "Highlander" battery, you could ask Keeppower to make them for you.


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## ChrisGarrett (Jul 24, 2012)

HKJ said:


> Sorry that I forgot to answer that question.
> 
> For any protected battery a company must add the protection circuit, rewrap the cell and add a label, as OEM Keeppower will do that for other companies.
> 
> I.e. if you want to sell a "Highlander" battery, you could ask Keeppower to make them for you.



HKJ,

What's the deal with the green Pannie 18650Bs charging up to 4.35 volts? Can these be charged (if they had a + button) on something like my Xtar WP2 II, or does one need a hobby charger?

Also, how come the Keeppower 3400s, using the same cell can only charge up to 4.2v? Is that just the protection circuit, or is that newer Pannie just a higher voltage cell, like some of the other brands/models that you have tested in the past...like the Samsung, or LG?

Chris


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## HighlanderNorth (Jul 24, 2012)

HKJ said:


> Sorry that I forgot to answer that question.
> 
> For any protected battery a company must add the protection circuit, rewrap the cell and add a label, as OEM Keeppower will do that for other companies.
> 
> I.e. if you want to sell a "Highlander" battery, you could ask Keeppower to make them for you.




When I get my 1st delivery of Highlander 3400mah 18650's in, I'll need them reviewed, after KeepPower sends them to me.


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## samgab (Jul 24, 2012)

Wow, these Panasonic cells are impressive. Even work well at high current loads. And Keeppower's PCB seems to do the business, again, even at high current. I wonder how we could do a group buy or something, as they have them on their site in 100 lot batches... Is the marketplace the proper forum for that discussion?


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## Norm (Jul 24, 2012)

samgab said:


> Is the marketplace the proper forum for that discussion?



Here: Group Buys and Passarounds

Norm


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## HKJ (Jul 24, 2012)

ChrisGarrett said:


> HKJ,
> 
> What's the deal with the green Pannie 18650Bs charging up to 4.35 volts? Can these be charged (if they had a + button) on something like my Xtar WP2 II, or does one need a hobby charger?
> 
> Also, how come the Keeppower 3400s, using the same cell can only charge up to 4.2v? Is that just the protection circuit, or is that newer Pannie just a higher voltage cell, like some of the other brands/models that you have tested in the past...like the Samsung, or LG?



The "Official specifications" are the dealers specifications and that is a typo from cnqualitygoods.


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## Colonel Sanders (Jul 25, 2012)

"Can these be charged (if they had a + button) on something like my Xtar WP2 II, or does one need a hobby charger?"

The bare green cells charge fine in my Xtar SP2 so I would think you should be fine with a WP2.


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## RedForest UK (Jul 25, 2012)

ChrisGarrett said:


> What's the deal with the green Pannie 18650Bs charging up to 4.35 volts?



Yes, that was nothing more than a mistake by Ric when listing them on cnqualitygoods website. They are not 4.35v but 4.2v just as the previous cells in the NCR series.


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## 45/70 (Jul 25, 2012)

Thanks for yet another review, HKJ. That should go without saying.

I'm seeing a trend, with these NNP cells anyway, that while not exactly the same, is similar to the situation with high cap NiMH cells. This 3400mAh version holds voltage under load better than the earlier versions, but is still not quite as good as most quality 2600mAh cells, including Keeppower's own.

I'm not saying they are not impressive cells, they are. Their best use though is in low to medium current drain applications, or when used in series. Under these conditions they're hard to beat. If you want the most available power throughout discharge though, the 2600mAh cells are still better. As I said, this reminds me of the difference between ~2000mAh and 2500-2700mAh NiMH cells. In the right situation, they work great, but have their limitations.

Dave


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## Colonel Sanders (Jul 25, 2012)

Dave, I'm not disagreeing with you but just curious...what would you think the running voltage would be down to after 20 minutes at a 4a load with a quality 2600? In my testing the 3400s were down to 3.46v running voltage and down to 3.28v after 30 minutes.

EDIT: HJK has the 3a and 5a info on 2600s and 3400s so I'll summarize... 

20 min 3400 v/s 2600
3a 3.48-3.56
5a 3.22-3.30

30 min
3a 3.4-3.48
5a 3.0-NA

So yes, the 2600s do a little better until they start going downhill.


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## Shadowww (Jul 26, 2012)

At 3A (typical draw in flashaholic lights), 3400mAh Pannie's hold higher voltage than 2600mAh batteries *most* of the time.




But at 5A, Panasonics hold higher voltage *all* the time.


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## 45/70 (Jul 26, 2012)

Hi Shadowww. Your comparison is noted, but it compares an unprotected cell to a protected one. There is always some inefficiency (= voltage drop) when adding a protection circuit to a cell.

For a more "apples to apples" comparison, compare Keeppower's 3400mAh protected cell to their own 2600mAh protected cell, with HKJ's comparator (excellent tool HKJ!), and things look quite a bit different, at both current rates.

Also keep in mind that in single cell lights, the voltage usually doesn't become critical until cell voltage drops to the Vf of the LED, plus the overhead of the light's driver. This voltage value will be different with different setups, current levels etc, but with modern LEDs and drivers is generally in the 3.3-3.5 Volt range, at higher outputs.

Dave


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## jasonck08 (Jul 26, 2012)

45/70 said:


> I'm seeing a trend, with these NNP cells anyway, that while not exactly the same, is similar to the situation with high cap NiMH cells. This 3400mAh version holds voltage under load better than the earlier versions, but is still not quite as good as most quality 2600mAh cells



NNP cells are 3.6v nominal voltage cells with a 2.5v cutoff (I believe this has to do with the added Nickel). Most 2600's are 3.7v nominal voltage cells.

These are capable of higher loads than 2600's, however the 2600's may still hold higher voltage due to the chemistry of the cell. The interesting part of it though is the 3400's have a lower internal resistance than any 2600.


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## 45/70 (Jul 27, 2012)

jasonck08 said:


> ......The interesting part of it though is the 3400's have a lower internal resistance than any 2600.



Good points and observations, Jason. I'm getting a bit out of my league here maybe, but isn't the internal resistance of cells measured with pulsed AC through a basically static cell?

I would think that a cell under load would have changing IR, depending on the current load applied. The higher the current load, the higher the IR. In this case, and again I'll admit to being on shaky ground here, it would appear that the 2600mAh cells actually have a lower IR under load, at least from a point about halfway through the discharge, this point also being somewhat dependent on the current load applied.

I also want to point out that I am in no way, shape, or form, bashing the 3400mAh NNP cells! They are terrific cells, no doubt. I am just seeing that while they have some really great advantages, they also have some shortcomings. There seems to be a bit of a tradeoff here. A classic example of "you can have one or the other, but not both". In this case, voltage maintenance under load, or capacity.

Dave


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## Ualnosaj (Jul 30, 2012)

Hmmm... is the extra few hundred mAh worth the possible price premium? Let's see what can be done with a high MOQ...


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## Shadowww (Jul 30, 2012)

Ualnosaj said:


> Hmmm... is the extra few hundred mAh worth the possible price premium? Let's see what can be done with a high MOQ...


$6.41/piece for the base cell if you order 100 or more.. Considering that NCR18650A can be gotten for $6/piece, this makes it "extra few cents" more expensive, which is fair enough for "extra few hundred mAh".


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## Ualnosaj (Jul 31, 2012)

Shadowww said:


> $6.41/piece for the base cell if you order 100 or more.. Considering that NCR18650A can be gotten for $6/piece, this makes it "extra few cents" more expensive, which is fair enough for "extra few hundred mAh".



I meant at retail of 3100 vs 3400 assembled protected battery  we'll be talking about more than a few cents there.



________________
Sent from my mobile device. Please excuse the brevity of this message.


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## Shadowww (Jul 31, 2012)

Ualnosaj said:


> I meant at retail of 3100 vs 3400 assembled protected battery  we'll be talking about more than a few cents there.


Protected 3400's are overpriced atm because there's no competition (only Keeppower and Orbtronic sell them), as soon as others will catch up (Eagletac, AW, Xtar, RediLast, Kallie's Customs, etc) prices will drop.


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## ChrisGarrett (Jul 31, 2012)

Orbtronics has gone MIA for the last week, or two. They've pulled all of their Ebay ads and most of their offerings on their own website are being listed as OUT OF STOCK.

Can't say what's happening, but maybe a long vacation?

Chris


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## tobrien (Jul 31, 2012)

ChrisGarrett said:


> Orbtronics has gone MIA for the last week, or two. They've pulled all of their Ebay ads and most of their offerings on their own website are being listed as OUT OF STOCK.
> 
> Can't say what's happening, but maybe a long vacation?
> 
> Chris


I was tweeting with them. Theyre in the eu picking up new products. Rest assured its a productive vacation.


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## samgab (Aug 3, 2012)

The thing is, you always pay a premium to have the best, the fastest, the strongest, the smallest, the biggest... anything the ****-est, even if it is just a small margin.
Look at how much extra people pay for the fastest CPU currently available at any given time, even though it's only a few clocks faster than the next one down.
This Panasonic cell currently holds the most capacity for an 18650 cell, so yes, there is a premium, which some of us are willing to pay.
And from the performance testing HKJ did, it appears that as well as just a few extra mAh, this cell is a solid performer in terms of current handling and voltage levels.


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## sidness (Aug 23, 2012)

Does anyone have an educated guess as to when the 3400mah cell will be supplied by aw, eagletac, etc.
Orbtronic is no good for me, as i live in England.


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## CyberCT (Nov 5, 2012)

sidness said:


> Does anyone have an educated guess as to when the 3400mah cell will be supplied by aw, eagletac, etc.
> Orbtronic is no good for me, as i live in England.



Any updates on this? Looking to buy new cells just for the TK75 (hope these will fit in it, I'll have to do more research).


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## flame2000 (Nov 5, 2012)

CyberCT said:


> Any updates on this? Looking to buy new cells just for the TK75 (hope these will fit in it, I'll have to do more research).



Eagletac 3400mAh is available at Goinggear and Fstoplight.


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## Shadowww (Nov 5, 2012)

sidness said:


> Does anyone have an educated guess as to when the 3400mah cell will be supplied by aw, eagletac, etc.
> Orbtronic is no good for me, as i live in England.


Why not grab Keeppower ones from eBay, at $29/pair? Also Intl-Outdoor store has 3400mAh batteries, for same price.
They use same cell (and very similar protection circuit), but the difference is that Keeppower batteries have button-top, and Intl-Outdoor ones have raised top.


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## CM2010 (Nov 5, 2012)

CyberCT said:


> Any updates on this? Looking to buy new cells just for the TK75 (hope these will fit in it, I'll have to do more research).



flashaholics sell the Eagletac 3400's.


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## snakyjake (Nov 5, 2012)

I like the low internal resistance (heat?).
Wish that it had a metal bottom.
Wonder if the protection trip is too high (but I haven't seen any tests that tell us what is better/worse).
I'd love to see these batteries stress tested for safety evaluation.

Thanks for the review. Jake.


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## CyberCT (Nov 5, 2012)

CM2010 said:


> flashaholics sell the Eagletac 3400's.



I haven't seen any reviews on these yet, which is surprising ...


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## Atreides (Nov 25, 2012)

Hello to everyone. Feel this is kindda "required" since I have re-connected kindda recently.

I can only offer one answer to the question about the middleman.

Often, large OEM manufacturers only sell to high volume buyers. This is not "stupid" to -say- abstain from small volume sales. It just means that the company policy lacks the inclination (they see lower profit margins usually) in supporting low volume sales. This is the case with many manufacturers. Just to name a few "Lite-On" and "Delta Electronics". Try purchasing a single fan from Delta. Its impossible. You have to order 1000 pcs minimum to get a single -worst possible- quotation. So, to me it is no surprise if "Keepower" has the money to purchase cells from Panasonic but another small company cannot afford to do so. Usually, to negate such problems the manufacturers themselves -Panasonic in this case- introduce such companies to each other, in order to provide limited services. To Panasonic its all the same, since the volume of the new buyer is routed through their Keepower client.

Of-course, what I am saying is not THE explanation (since I don't handle orders for Panasonic). But it does provide a (in my opinion) solid -as in rational- explanation of what MIGHT be going on.

In any case, thank you for taking the time to read my reply! and also, trust your own brains, rather than what you see or hear. Talking/typing is cheap.
Atreides



HighlanderNorth said:


> What would be(if any) potential disadvantage or downside to using a battery with this much capacity in an LED flashlight, or in any other device? I would assume that if there was an over-discharge or short circuit it would potentially be more dangerous due to the higher energy capacity, but is there any higher risk of that happening with a high capacity battery vs. a 2200, 2600, 2900 mah battery
> 
> Are there any other potential disadvantages of using a really high cap battery vs a lower cap battery?
> 
> ...


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## troelskc (Dec 1, 2012)

Just got 2 fine batteries today. The came charged @ 3.64 v which is a kind of low storage voltage? Recommended is 40% which I calculates to 3.78 V.


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## HKJ (Dec 1, 2012)

troelskc said:


> Just got 2 fine batteries today. The came charged @ 3.64 v which is a kind of low storage voltage? Recommended is 40% which I calculates to 3.78 V.



I do not really believe it matters much if it is 20% or 60% you use for storage.
But your calculations are way off, I did some measurement on remaining capacity versus voltage.


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## Shadowww (Dec 1, 2012)

troelskc said:


> Just got 2 fine batteries today. The came charged @ 3.64 v which is a kind of low storage voltage? Recommended is 40% which I calculates to 3.78 V.


Panasonic apparently ships their cells at 3.65V, so 3.64V is perfectly fine.


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## tobrien (Dec 2, 2012)

troelskc said:


> Just got 2 fine batteries today. The came charged @ 3.64 v which is a kind of low storage voltage? Recommended is 40% which I calculates to 3.78 V.



mine come at that voltage always


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## troelskc (Dec 3, 2012)

HKJ said:


> I do not really believe it matters much if it is 20% or 60% you use for storage.
> But your calculations are way off, I did some measurement on remaining capacity versus voltage.



Interesting. Things are not always simple 
39% = 3.6V @ 1A discharge


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## hellokitty[hk] (Dec 3, 2012)

troelskc said:


> Interesting. Things are not always simple
> 39% = 3.6V @ 1A discharge


I would be interested in seeing a 4.35v battery like the LG D1 tested like this.


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## HKJ (Dec 3, 2012)

hellokitty[hk] said:


> I would be interested in seeing a 4.35v battery like the LG D1 tested like this.



I did not want to confuse the tables with other voltages, but if more people want it, I can easily do it.
It is probably best to discus it in the correct thread.


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## CyberCT (Dec 19, 2012)

Still none on ebay. I wonder why??


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## Shadowww (Dec 19, 2012)

CyberCT said:


> Still none on ebay. I wonder why??


http://myworld.ebay.com/doingoutdoor/ is no longer a registered user. That sucks, they were best dealer for Keeppower cells


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## tobrien (Dec 19, 2012)

Shadowww said:


> http://myworld.ebay.com/doingoutdoor/ is no longer a registered user. That sucks, they were best dealer for Keeppower cells



that's really strange, i wonder why?


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## gopajti (Dec 20, 2012)

Don't worry guys, 3400mAh Keeppower available on cnqualitygoods, $13.50/1pcs


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## Dubois (Dec 20, 2012)

Shadowww said:


> http://myworld.ebay.com/doingoutdoor/ is no longer a registered user. That sucks, they were best dealer for Keeppower cells



Same thing happened last month - doingoutdoor went away for a while. Might just be that the owner is on holiday, and will be back in the New Year (hopefully). Unfortunately he stopped shipping to a few places (including the UK) some time ago.


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## CyberCT (Dec 20, 2012)

I was going to pick these up and a TK75. I'll have to look into the shipping time from China.


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## Justin Case (Dec 20, 2012)

HKJ said:


> I cannot see any disadvantages from a large capacity, there might be other disadvantages, not directly related to capacity, like: battery size, battery voltage, maximum current.





45/70 said:


> I'm seeing a trend, with these NNP cells anyway, that while not exactly the same, is similar to the situation with high cap NiMH cells. This 3400mAh version holds voltage under load better than the earlier versions, but is still not quite as good as most quality 2600mAh cells, including Keeppower's own.
> 
> I'm not saying they are not impressive cells, they are. Their best use though is in low to medium current drain applications, or when used in series. Under these conditions they're hard to beat. If you want the most available power throughout discharge though, the 2600mAh cells are still better. As I said, this reminds me of the difference between ~2000mAh and 2500-2700mAh NiMH cells. In the right situation, they work great, but have their limitations.
> 
> Dave





45/70 said:


> I also want to point out that I am in no way, shape, or form, bashing the 3400mAh NNP cells! They are terrific cells, no doubt. I am just seeing that while they have some really great advantages, they also have some shortcomings. There seems to be a bit of a tradeoff here. A classic example of "you can have one or the other, but not both". In this case, voltage maintenance under load, or capacity.
> 
> Dave



45/70 has the downside of higher capacity cells exactly right. And the downside is directly related to capacity. Cells that maximize capacity try to maximize the amount of active electrode material. Cells that maximize high-rate performance optimize electrode and reaction kinetics. The classic examples are the bobbin vs. spirally wound designs. The bobbin is great for capacity since it maximizes the amount of electrode material, but it sacrifices surface area for electrochemical reaction. In contrast, the spiral wound design uses thin electrodes that increase surface area, but at the expense of the amount of active material and thus capacity.


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## CyberCT (Dec 20, 2012)

The main purpose of my TK75 use would be the medium and high modes, with bursts of turbo momentarily. I belive the TK75 uses the 2S2P configuration for the 4 cells it takes. Fenix also lets you add another adapter and battery carrier so you can use 8 cells instead of just 4. the addional 4 cells would be like adding a second large "battery" in where it's an addition of a parallel configuration. So for my purpose these batteries should work quite nicely!


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## CyberCT (Dec 22, 2012)

Well I ended up buyiing 10 off the cnquality goods website and paid for the faster shipping option. If you buy min quantitiy of 10 the price drops $2 per cell, so I couldn't resist. I also bought the TK75 and the 2nd adapter, so I will be using 8 of these in that light. The 2 remaining ones will go in my TK53.

My question now is, what is the best QUALITY charger to use with these batteries? I have a Pila IBC charger which I have been using for all my AW Panasonic 2900mah batteries before. It's only 2 bays though, and I want something that is more bays and will fit these newer larger batteries.


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## Shadowww (Dec 22, 2012)

CyberCT said:


> My question now is, what is the best QUALITY charger to use with these batteries? I have a Pila IBC charger which I have been using for all my AW Panasonic 2900mah batteries before. It's only 2 bays though, and I want something that is more bays and will fit these newer larger batteries.


Get Xtar SP2, it'll charge 2 batteries approx. 3 times faster than Pila IBC (and therefore, you can charge 6 batteries in same time it takes IBC to charge just 2).


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## CyberCT (Jan 4, 2013)

I got my 10 Keeppower 3400mah batteries in the mail. They all came at 3.63v-3.64v. Is this too low, or OK? My AW 2900mah batteries arrived at 3.8v when I bought them 2 years ago.

I bought 2 of the Nitecore Intellicharger I4 V2 chargers, and have my current Pila IBC Charger, so I can charge all 10 at the same time if I need to. The batteries get warm in the PILA like the AWs, but because the charge current is higher so hopefully they charge in about 3 hours. The Nitecore charger will probably take around 12 hours unfortunately.


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## TEEJ (Jan 4, 2013)

I've been lovin' the Xtar WP6 II charger (6 bay) as HJK blessed it, and, its been flawless. 

6 Cells at a time is a real time saver.


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## Shadowww (Jan 5, 2013)

CyberCT said:


> I got my 10 Keeppower 3400mah batteries in the mail. They all came at 3.63v-3.64v. Is this too low, or OK? My AW 2900mah batteries arrived at 3.8v when I bought them 2 years ago.


That's OK, that is voltage at which Panasonic cells come out of the factory.


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## __philippe (Jan 30, 2013)

Dubois said:


> Same thing happened last month - doingoutdoor went away for a while. Might just be that the owner is on holiday, and will be back in the New Year (hopefully). Unfortunately he stopped shipping to a few places (including the UK) some time ago.



Not to worry, *DoingOutdoor* opened their own web site during January 2013:

http://www.doingoutdoor.com/

Cheers,

__philippe


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## tobrien (Jan 30, 2013)

__philippe said:


> Not to worry, *DoingOutdoor* opened their own web site during January 2013:
> 
> http://www.doingoutdoor.com/
> 
> ...



nice find, thanks!


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## gopajti (Feb 14, 2013)

new 3400mAh Keeppower batteries came from doingoutdoor. Both cells are 3.62V, shipping time, 8 working days to Hungary. Excellent!


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## Dubois (Feb 15, 2013)

Good that doingoutdoor is back, but he will no longer ship batteries to the UK or Germany. He still has some good deals on lights though, so not all bad news.


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## Lurveleven (Feb 21, 2013)

Have you given cnqualitygoods approval for using your table?


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## HKJ (Feb 21, 2013)

Lurveleven said:


> Have you given cnqualitygoods approval for using your table?



No, and the photos does also look like it is mine.

Generally people are welcome to use my pictures, curves and table, but I prefer that they add a credit to my website (On the forum it is fine just saying it is from HKJ).


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## Lurveleven (Feb 21, 2013)

I think that is pretty rude of them, and they have even edited the picture and removed the reference to www.lygte-info.dk. The most funny thing is that they have branded them with their own logo so no one else can steel them. If this is a reflection of their business ethics, then I don't want to be their customer.
I see that www.doingoutdoor.com is also borrowing your tables, but they have used the originals with your web site reference.


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## HKJ (Feb 21, 2013)

Lurveleven said:


> I think that is pretty rude of them, and they have even edited the picture and removed the reference to www.lygte-info.dk. The most funny thing is that they have branded them with their own logo so no one else can steel them. If this is a reflection of their business ethics, then I don't want to be their customer.
> I see that www.doingoutdoor.com is also borrowing your tables, but they have used the originals with your web site reference.



I have written an email to cnq and asked them to include a link to my review or at least mention my website. I wonder what they will answer.


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## Verndog (Feb 21, 2013)

troelskc said:


> Just got 2 fine batteries today. The came charged @ 3.64 v which is a kind of low storage voltage? Recommended is 40% which I calculates to 3.78 V.



I ran a discharge test on Panasonic 3100 EagleTac cells and here is what i found on my hobby charger. 4.2V 100%, 4.0V 82%, 3.66V 50%, 3.35V 0%. 

This was watching the mah discharged then stopping discharge and checking idle voltage along the way. Judging from my findings, you received pretty close to a 50% charged cell.


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## HKJ (Feb 21, 2013)

Verndog said:


> I ran a discharge test on Panasonic 3100 EagleTac cells and here is what i found on my hobby charger. 4.2V 100%, 4.0V 82%, 3.66V 50%, 3.35V 0%.
> 
> This was watching the mah discharged then stopping discharge and checking idle voltage along the way. Judging from my findings, you received pretty close to a 50% charged cell.




I did some tests to see how much charge was left at specific voltages, it varies with the battery type and with the time from you stop the discharge, until you measure.


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## Verndog (Feb 21, 2013)

HKJ said:


> I did some tests to see how much charge was left at specific voltages, it varies with the battery type and with the time from you stop the discharge, until you measure.



Agree, as the voltage will bounce back some over time. But looking at your 3100 chart, it's spot on to what I just posted at 50%. 

Also, the discharge amps will have some effect...I used a moderate .7A discharge rate to reduce bounce back voltage.


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## HKJ (Feb 21, 2013)

Verndog said:


> Also, the discharge amps will have some effect...I used a moderate .7A discharge rate to reduce bounce back voltage.



I only believe that the discharge current can be seen for a short time, if I had rested 24 hours for each measurement, the result had probably been the same, independent of discharge current.


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## Verndog (Feb 21, 2013)

HKJ said:


> I only believe that the discharge current can be seen for a short time, if I had rested 24 hours for each measurement, the result had probably been the same, independent of discharge current.



That makes sense. Also it's worth noting from your tests the voltage vs % remaining looks fairly close from the 3100 to the 3400 versions from what I can tell.


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## HKJ (Feb 21, 2013)

Verndog said:


> Also it's worth noting from your tests the voltage vs % remaining looks fairly close from the 3100 to the 3400 versions from what I can tell.



Yes, that is probably because they are very close in chemistry.


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## Verndog (Feb 21, 2013)

HKJ said:


> Yes, that is probably because they are very close in chemistry.



Wish I would have seen this before I spent the time to watch, stop, and check my cells manually. But as I just was getting started in 18650's I wanted to know my cells and exactly where they are. It's good to know my test matches your findings almost perfectly, you show closer to 3.3V dead where I got 3.35, but that's fine as the drop is very quick when dead.


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## HKJ (Feb 21, 2013)

Verndog said:


> Wish I would have seen this before I spent the time to watch, stop, and check my cells manually. But as I just was getting started in 18650's I wanted to know my cells and exactly where they are. It's good to know my test matches your findings almost perfectly, you show closer to 3.3V dead where I got 3.35, but that's fine as the drop is very quick when dead.



For the 3100mAh I got (1A test):

2700mAh after 10 sec: 3.281 volt, after 1 hour: 3.345 volt
2800mAh after 10 sec: 3.177 volt, after 1 hour: 3.321 volt
2897mAh after 10 sec: 2.935 volt, after 1 hour: 3.285 volt 

As you can see I did the test in 100mAh increments.

But if you compare 1300mAh batteries in my comparator, you will see that there is some small differences between them.


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## __philippe (Feb 21, 2013)

Thanks for HKJ's very handy 18650 cells comparison tool: 

http://lygte-info.dk/review/batteries2012/Common18650comparator.php

__philippe


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## yoyoman (Feb 21, 2013)

Just purchased some of these for a Deft-X. I will get them way before I get the light unfortunately. (Thank you Philippe for tipping me off to a site that will ship to Switzerland.)


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## R10500 (Apr 7, 2013)

has anybody looked on alibaba recently and found this particular supplier selling one from 2-6$, no minimum order? gut instincts tell me not to trust that but i'm wondering if anybody can chime in on this. would be great if there are even cheaper suppliers out there apart from cnqualitygoods


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## __philippe (Apr 8, 2013)

Check post #56 above for the real McCoy.


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## Dubois (Apr 8, 2013)

Only problem is that doingoutdoor does not ship batteries to the UK, Germany or Italy.


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## gilson65 (Apr 10, 2013)

will they fit in the sunwayman t20cs and is mah to high for this torch newbie to 18650 batterys have done several searches without finding the answer thanks tony


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## yoyoman (Apr 10, 2013)

mAh refers to the capacity. These cells are a little fat - they won't fit into my Oveready bodies. Check the dimensions on the first page of the thread and then check your light.


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## __philippe (Apr 10, 2013)

Just measured a protected KeepPower 18650 (3400 mAh):

diameter *18.5mm* x Length *68.8mm*, give or take 0.1mm

__philippe


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## HKJ (Apr 10, 2013)

__philippe said:


> Just measured a protected KeepPower 18650 (3400 mAh):
> 
> diameter *18.5mm* x Length *68.8mm*, give or take 0.1mm



Length is the same as I got (Review at the start of the thread), but you got a smaller diameter. Did you measure at the thickest part of the circumference (That is where the strip is placed).


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## __philippe (Apr 10, 2013)

I took several measures round the circumference, and gave the average diameter *18.5mm, * along with the tolerances: _"give or take 0.1mm"...

___philippe


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## Dubois (Apr 10, 2013)

__philippe said:


> I took several measures round the circumference, and gave the average diameter *18.5mm, * along with the tolerances: _"give or take 0.1mm"...
> 
> ___philippe



Surely an average diameter is of less importance that the widest reading? An average 18.5mm wide cell may not fit in a 18.51mm wide tube wide cell if one part of it is 18.52, say.

That's why HKJ gives the widest diameter.


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## el_Pablo (Apr 10, 2013)

my 2x keeppower 3400mAh 18650 from doingoutdoor, were not the same diameter, one did fit tight on my bored Z2 (18.7) and the other one had to be force push in it (little pressure, not hammered into it)

the larger one after a full run on the light and a recharge was fitting like the first one. (shaking a little the light to slide them out)

i guess some dimensional modification after burn-in occured.


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## __philippe (Apr 10, 2013)

Dubois said:


> Surely an average diameter is of less importance that the widest reading? An average 18.5mm wide cell may not fit in a 18.51mm wide tube wide cell if one part of it is 18.52, say.
> 
> That's why HKJ gives the widest diameter.



Granted,...the widest diameter measured *on one's specific cell *is the relevant factor here...

However, if you measure a sample batch of a hundred cells, some variances around the *nominal 18.6 mm *diameter are bound
to be distributed alongside a statistical "bell shaped" curve, likely within a +0.2mm/-0.2mm interval...so, prospective buyers beware...

Anyway, we are talking about minuscule 1/10th of a millimeter variations here, mind you...


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## gilson65 (Apr 10, 2013)

thanks for the reply fellas


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## Doingoutdoor (Apr 16, 2013)

there's little different on the diameter and length of different.
if you need its exact size (0.02mm), please let us measure for you.
thanks
Bill Qiao


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## aus_sparky (Apr 27, 2013)

Before I lay out any money for a couple of these Keeppower 18650 cells, are there any issues fitting or otherwise with Olight M3X torches? Thanks.


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## aus_sparky (May 16, 2013)

I now have two Keeppower 3400mah batteries. I noticed that when the battery dropped to @ 2.8 volts the torch started to flash like it was in strobe mode. I tried it in another torch and did the same thing. Is this the protection circuit telling me it's time to charge? Is this normal?

Thanks, Robin.


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## HKJ (May 16, 2013)

aus_sparky said:


> I now have two Keeppower 3400mah batteries. I noticed that when the battery dropped to @ 2.8 volts the torch started to flash like it was in strobe mode. I tried it in another torch and did the same thing. Is this the protection circuit telling me it's time to charge? Is this normal?
> 
> Thanks, Robin.



If the 2.8 volt is measured unloaded, i.e. with the battery out of the light, it might be the protection or the driver in the light.


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## aus_sparky (May 17, 2013)

HKJ said:


> If the 2.8 volt is measured unloaded, i.e. with the battery out of the light, it might be the protection or the driver in the light.


Thanks for the reply HJK. 2.8 was the unloaded voltage. I don't think it is the light itself as the original Ferei battery didn't do it when it got very low (which may also show that the Ferei battery isn't protected). As long as it's normal, I'm happy.


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## Bullzeyebill (May 18, 2013)

I have removed two posts with links to dealers. This is a review thread, not a thread concerned with the buying of Li-Ion batteries.

Bill


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## InquisitiveInquirer (Jul 26, 2013)

Has anyone tried fitting these into a Nitecore SRT7? I was thinking of picking some up.


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## neutralwhite (Dec 24, 2013)

hi what's the best way to charge keeppowers 2600's?.

0.5, or 1A ?.
XTAR VP1. 
thanks.


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## HKJ (Dec 24, 2013)

neutralwhite said:


> hi what's the best way to charge keeppowers 2600's?.
> 
> 0.5, or 1A ?.
> XTAR VP1.
> thanks.



All 2600mAh datasheets I have seen specify a charge current above 1A, i.e. 1A is fine for them.


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## neutralwhite (Dec 24, 2013)

thanks, the 1st charge of these were at 0.5A, was that OK?, and does 1A speed up the charge / 0.5 halve the time ?.
thanks.



HKJ said:


> All 2600mAh datasheets I have seen specify a charge current above 1A, i.e. 1A is fine for them.


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## HKJ (Dec 24, 2013)

neutralwhite said:


> thanks, the 1st charge of these were at 0.5A, was that OK?, and does 1A speed up the charge / 0.5 halve the time ?.
> thanks.



0.5A charge is perfectly ok, it just takes longer time.
Doubling the charge current will reduce the charge time, but to to half the time. It is difficult to estimate the time reduction. The CC phase will be shorter, but the CV phase will be longer.


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## neutralwhite (Dec 24, 2013)

thanks, is that longer CV phase a problem?.
what does it briefly mean if you could please ?.

thank you, 


HKJ said:


> 0.5A charge is perfectly ok, it just takes longer time.
> Doubling the charge current will reduce the charge time, but to to half the time. It is difficult to estimate the time reduction. The CC phase will be shorter, but the CV phase will be longer.


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## HKJ (Dec 24, 2013)

neutralwhite said:


> thanks, is that longer CV phase a problem?.
> what does it mean?.
> 
> thank you,



No problem, just an explanation. 
The CC phase might be half time, but because it takes longer to reduce current from 1A to 0.1A, than from 0.5A to 0.1A (0.1A is the termination current), the CV phase will take longer.


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## Tapis (Oct 5, 2014)

Sorry to bump the thread. Newbie here not truly enlightened yet. I just bought two of these. Can I recharge them with the Fenix ARE-C1 charger I already have for my 2600mAh batteries or should I buy a new, more powerful charger?


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## UnderPar (Oct 5, 2014)

That charger is really designed for 18650 rechargeable batteries. No doubt you can use it. The 3.5 hours charging time in the Fenix website is for 2600 mAh batteries. It will be longer for 3400 mAh batteries depending on up to what degree it is discharged. HTH


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## SubLGT (Jul 31, 2015)

Interestingly, this battery is now available from KP as a single, in a blister pack:

http://www.keeppower.com.cn/products_detail.php?id=525

Perfect for hanging on the rack at Home Depot.


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## markr6 (Jul 31, 2015)

SubLGT said:


> Interestingly, this battery is now available from KP as a single, in a blister pack:
> 
> http://www.keeppower.com.cn/products_detail.php?id=525
> 
> Perfect for hanging on the rack at Home Depot.



Nice! I'm still looking for the 3500mAh UNprotected cell. I'm just curious in the price but can't find it anywhere.


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## 1DaveN (Jul 31, 2015)

markr6 said:


> Nice! I'm still looking for the 3500mAh UNprotected cell. I'm just curious in the price but can't find it anywhere.



When I was on the Orbtronic site looking at 3500 mAh protected cells, I noticed a link to unprotected ones at the bottom of the listing, so take a look there. (They seem to be out of stock on pretty much everything, though).


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## markr6 (Jul 31, 2015)

1DaveN said:


> When I was on the Orbtronic site looking at 3500 mAh protected cells, I noticed a link to unprotected ones at the bottom of the listing, so take a look there. (They seem to be out of stock on pretty much everything, though).



I see, thanks. Still not the KP branded cell, but same difference I guess. Sorry, I derailed the thread!


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## candle lamp (Dec 19, 2015)

Hi HKJ!

Do you know the voltage when the protection circuit trips for preventing overdischarge (e.g. 2.5V or else)?


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## HKJ (Dec 19, 2015)

candle lamp said:


> Do you know the voltage when the protection circuit trips for preventing overdischarge (e.g. 2.5V or else)?



No, but I would expect between 2.00 and 2.50 volt, I did some test here: http://lygte-info.dk/info/DischargeProtectionTest UK.html


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## candle lamp (Dec 19, 2015)

Thanks for the helpful information. :thumbsup:



HKJ said:


> No, but I would expect between 2.00 and 2.50 volt, I did some test here: http://lygte-info.dk/info/DischargeProtectionTest UK.html


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## vestureofblood (Jan 21, 2016)

Hi HKJ,

I was just wandering, where it says "calculated resistance .09". Can you tell me how you do that?


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## HKJ (Jan 21, 2016)

vestureofblood said:


> Hi HKJ,
> 
> I was just wandering, where it says "calculated resistance .09". Can you tell me how you do that?



Check the chapter about "PCB trip current" here: http://lygte-info.dk/info/Batteries2012Info UK.html

This article may also be relevant: http://lygte-info.dk/info/Internal impedance UK.html


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## SeamusORiley (May 8, 2017)

late posting, but I have had much success with these batteries. Months ago, I bought four for TM 26 GT. My grown sons have another of my TM 26, as well as TM 06. I recently sold TM 26 GT to get 28 (I know, I know) and although I did not have it long, I loved these batteries in it. 

Mine were the 3400 mah and last a long time, even though I only used the light rarely. (I did not do much walking this winter due to other circumstances) but hopefully will be out walking the dog in the dark again; something I enjoy having a strong light for. (besides home defense)


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## TimeOnTarget (Jul 1, 2017)

SeamusORiley said:


> late posting, but I have had much success with these batteries. Months ago, I bought four for TM 26 GT. My grown sons have another of my TM 26, as well as TM 06. I recently sold TM 26 GT to get 28 (I know, I know) and although I did not have it long, I loved these batteries in it.
> 
> Mine were the 3400 mah and last a long time, even though I only used the light rarely. (I did not do much walking this winter due to other circumstances) but hopefully will be out walking the dog in the dark again; something I enjoy having a strong light for. (besides home defense)



Thanks for the report.

After reading this thread, I decided to order 2 of these cells for my new Olight S2 Baton. I am also waiting for the Olight branded battery to arrive as well.


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