pkcell 14500. surprise! rated 750mah got 844@500ma

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snakebite
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pkcell 14500. surprise! rated 750mah got 844@500ma

pkcell
got a pair of these to test.
844mah @ 500ma.
50mohm ir.
got some 10440 too.
they look to be the same cell efest relabels.
same ir too.
one set came from durnergy01.
other from fuspower2014.
orders were shipped together.

EasyB
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Nice find. I’m not sure about your IR reading though. How did you measure it? I ask because the best 14500 cells, like the windyfire, have around 70 mOhms.

snakebite
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EasyB
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Well if your measurements are correct this 14500 looks to be the best available.

snakebite
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812@1a

snakebite
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after 3 cycles my sample of 2 are 854 and 857 @ 500ma.
great performance from cheap cells.

AlexGT
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Looks like a great find, What charger/discharger are you using?

$6.99 shipped for 2 pieces? I’ll give them a try!

Thanks for the headsup! Beer

snakebite
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original triton.
charging at 650ma in a 8 bay “i8” blank charger.
they are rated for max of 1c charging so should be fine.
a lower rate would be better.
once my holders get here i will start on 10440 from the same seller.
650ma charge rate too high on those.will have to use a homebrew unit with a modified tp4056 or go slow by charging with the triton.
the pkcell and the efest 10440 both are right at 1.5a in my pf01s.
confidence is high they are the same cell without paying for a rewrapper middleman.

Muto
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Thanks for the heads up snakebite, ordered a set of both.
Got the 10440 with charger for less than the batts themselves:)

http://www.ebay.com/itm/2pcs-10440-AAA-Size-Li-ion-Rechargeable-Battery-...

Later,
Keith

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mrheosuper
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i still wait for more test, the wrapping look so cheap

Forgot my pen

EasyB
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There are also several reports of similar high capacity in the reviews here:
https://www.aliexpress.com/item/4Pcs-PKCELL-ICR14500-Battery-3-7V-750mAh...

But I’m still a little skeptical of the reported low IR. snakebite, do you happen to have a direct drive 14500 light that you can measure the current in to confirm the low IR?

snakebite
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the 10440 happily pushes 1.5a into an xp-g2.
the ir reading i get from the dick smith esr is the lowest i have seen in a 14500.
i will do a quick dd test later.
as a reference a sanyo 14500 shows 90mohms on the esr meter.

tempo
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How did you measure the IR?

snakebite
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Barkuti
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Nice find!

Made a search looking for a seller with free shipping to where I live. Result summary for anyone interested: “14500” search in DURNERGY store

 

Copper is mine, copper divine!

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snakebite
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10440 #1
366mah@200ma

snakebite
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the wrapping is not cheap.if the effort to trim the bottom overlap on the 10440 is any indication they will hold up just fine.

mrheosuper wrote:
i still wait for more test, the wrapping look so cheap
Barkuti
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snakebite wrote:

as a reference a sanyo 14500 shows 90mohms on the esr meter.

Well, just looking at HKJ's discharge graphs and crunching a few numbers my cold cell internal resistance estimation for the Sanyo UR14500P is almost 190mΩ.

Before HKJ reviewed the TrustFire IMR14500 (red-gold) I had already cooked a homemade internal resistance estimation for it, which came out at 80 & 82mΩ for the couple cells I had lying around at the time. Cold cell values, remember. Done by measuring cell resting voltage before and after applying charging current to it, averaging this value, and measuring cell voltage while charging current was being applied (at middle charging time lapse).

Also did that to six LiitoKala INR26650-50A cells, attaining nearly 23mΩ on average.

 

I'm not holding my breath with regards to discharge performance for these PKCELL cells.

 

Copper is mine, copper divine!

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JPLight
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Yes, nice find !

I have been searching for some good budged 14500 for some days now. So I will give them a try.

@Barkuti
Found the store as well with free shipping to Germany … ordered one lot. Thumbs Up

snakebite
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Barkuti dont hold your breath.
they fall on their face at 2a.
still beats the sanyo at 1a
they are rated at 1.5c max continuous.
remember these are icr.
and my sample of 1 sanyo droops even worse than these at 2a.
so its a cheap cell that still beats the sanyo at 1a

Agro
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snakebite wrote:
10440 #1
366mah@200ma

So much more than Efest which is 308mah@200ma or 281mah@2A according to HKJ and 276mah@2A according to accudb.
I wonder what are the discharge curves…
bguy
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The PK cells look to be unprotected ICR, where the Efest are IMR? That would account for the greater capacity.

I need more 14500, but I want either protected ICR or IMR chemistry.

snakebite
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this is where things get muddy.
pkcell is an oem.
efest a relabler.
who has been caught in lies before.
pkcell calls this cell icr.
it and the efest tested within 10mah under the same conditions.
physically the efest and pkcell are identical.the ir is identical.
who is lying?
guess.
at the price point of these i know which i would buy.
dont need to pay a middleman to slap a fancy sticker on it and charge more.

bguy wrote:
The PK cells look to be unprotected ICR, where the Efest are IMR? That would account for the greater capacity.

I need more 14500, but I want either protected ICR or IMR chemistry.