Test/Review of Keeppower 18650 3400mAh (Black)

[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

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.......

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.

i hope the same guy on eBay starts selling these!

thanks HKJ!

tobrien said:

i hope the same guy on eBay starts selling these!

thanks HKJ!

Click to expand...

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..

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?

Click to expand...

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.

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?

Click to expand...

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 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.

Click to expand...

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

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.

Click to expand...

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

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?

samgab said:

Is the marketplace the proper forum for that discussion?

Click to expand...

Here: Group Buys and Passarounds

Norm

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?

Click to expand...

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

"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.

ChrisGarrett said:

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

Click to expand...

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.

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

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.

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.

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

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

Click to expand...

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.

jasonck08 said:

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

Click to expand...

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