Cheap Li-Ion batteries 8000mah on ebay?

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Are these batteries good? Seems cheap for an 8 amp-hour Li-Ion battery. You  
get two for $7.77 plus $2 shipping, or maybe $5 apiece..


http://www.ebay.com/itm/2Pcs-26650-8000mAh-3-7v-Li-ion-Rechargeable-Battery-Cell-For-Electric-Tools-/111819891266?hash=item1a08fc2242:g:AfoAAOSw14xWKZ1t


DESCRIPTION:
Quantity:2
Standard voltage is 3.7V,
the voltage of full charge & empty condition is 4.2v & 2.5v respectively
Particularly suitable for flashlight, electric tools, electric bicycles,  
electric vehicles
Capacity: 8000mAh
Voltage: 3.7V
Material: Li-ion

Dimension: 67 mm (H)x 26 mm (Dia)
Color:Green

Package included:
2x UltraFire Green 26650 8000mAh Batteries









Re: Cheap Li-Ion batteries 8000mah on ebay?
On 19/11/15 14:45, Bill Bowden wrote:
Quoted text here. Click to load it

They lie. The very best 26650 Li-Ion are the Panasonic NCR cells, which  
are about 5000mAH. The Ultrafire cells would be typically 1/3 of that,  
or 1600mAH. Likewise all the other *fire Chinese brands (TrustFire,  
SureFire, CatchOnFire, etc).

Furthermore, there's a whole industry repackaging dead cells scavenged  
from old equipment.

Clifford Heath.

. You
Quoted text here. Click to load it

Quoted text here. Click to load it


Re: Cheap Li-Ion batteries 8000mah on ebay?
 =

wrote:

Quoted text here. Click to load it
y
h  =

Quoted text here. Click to load it
  =

Quoted text here. Click to load it

  =

Quoted text here. Click to load it

No I think you exaggerate. I have never seen a *fire cell deliver 1/3 of=
  =

the printed capacity - I think it is normally even less!

Seriously to the OP, avoid *fire brands like the plague, apart from the =
 =

dodge capacity labels most of them don't last long either. They will  =

probably be the most expensive batteries you evet buy in terms of total =
 =

power delivered and it will let you down when you need it most.


Quoted text here. Click to load it
attery-Cell-For-Electric-Tools-/111819891266?hash3D%item1a08fc2242:g:Afo=
AAOSw14xWKZ1t
Quoted text here. Click to load it
ely
es,


Re: Cheap Li-Ion batteries 8000mah on ebay?
On a sunny day (Thu, 19 Nov 2015 01:46:11 -0800) it happened mike

Quoted text here. Click to load it

Well I really do not know,
2 years ago I posted this here
        https://groups.google.com/forum /#!searchin/sci.electronics.design/Re$3A$209V$20Battery$20or$202$20x$20AAA$20with$209V$20Converter|sort:relevance/sci.electronics.design/DbgPnYXfGcY/KndUBmUUj7AJ
(scroll down, it says:):
"
 here one of my flashlights, with battery out:
 http://panteltje.com/pub/Cree_rechargable_flashlight_IMG_4478.JPG
 Li-ion, rechargeable, 3.7V 3.2Ah, LED, has several brightness stages,
 flashing mode too, came with charger.
 I have several smaller Cree ones, those all have Eneloop AAA  those,
 and will still work a year after charging.
  All ebay stuff.
 The big Cree has as defect that it melted the plastic around the LED
 when I left it on to test how long the battery lasted.
 Now the beam looks a bit different...
"
So it delivered a real amount of power for a long time, the flashlight melted,
the batteries are still OK.
Fixed the flashlight, it was not properly assembled....
So far I have no complaints.
Since I took out the spare utra-fire battery just now,
I am recharging it in all by itself in that 2 x charger you mention  
and that is still on.
No smoke from that area yet..
It was at 3.85 V, but OK..

Yes, sure I read those stories in the news of people getting burned to death or something using Li-ion or whatever...
There is one in every laptop?
Batteries is a consumable, I have plenty more problems with lead acid, be it sealed or
just normal car batteries, than with these Li-ions or lipos.

It is important that the flashlight works for a reasonable amount of time if you have not used it.
Since I DO use it more often .. I dunno, but this spare battery I am charging now
was still near almost? full, and that was a bad one.

I have eneloops in a smaller LED flashlight, those work OK too,
and are used several times a day, for example for inspection of stuff.

If yer life depends on it, then you need to keep several flashlights maybe with several battery technologies,
a fire maker, drinking water, gun to shoot deer, and of course your cellphone
to call for help.. ;-)

I do not normally buy at flee markets....
ebay is much better.

And that is my experience.

Maybe somebody should measure discharge times....
Maybe somebody has.

Still it may be different for different batches / sources.



Re: Cheap Li-Ion batteries 8000mah on ebay?
Someone who claims to be into technology should be able to quote more
than one level. Most of this stuff is a repeat of its prior post.  

--  
Jan Panteltje <pNaOnStPeAlMtje yahoo.com> wrote in news:n2kb4r$dcb$1 news.datemas.de:

Quoted text here. Click to load it
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On a sunny day (Thu, 19 Nov 2015 13:45:54 -0000 (UTC)) it happened John Dodo

Quoted text here. Click to load it

I post from experience with thrse batteries,
something you do not seem to have and so should shut the f*ck up.

At the most I can see you as an undercover agent for 'brand name' batteries.
BTW 'brand' in Dutch means: FIRE.

Or maybe you also walk with head down there under?



Re: Cheap Li-Ion batteries 8000mah on ebay?
On 19/11/15 19:35, David Eather wrote:
Quoted text here. Click to load it

I have three pairs of *fire 18650's that do 1200mAH, whereas the NCRs do  
3400, so I think 1/3 is possible - though I know others have measured  
less than 800mAH.

Quoted text here. Click to load it

I don't think they were that bad, $AU4/ea compared with $AU12 - about  
right for the capacity.

Clifford Heath.


Re: Cheap Li-Ion batteries 8000mah on ebay?
On Thu, 19 Nov 2015 09:12:43 GMT, Jan Panteltje

Quoted text here. Click to load it

Yes, but was it a real or counterfeit UltraFire battery?
<http://www.ultrafire.net/shownews.asp?id60%
<https://www.google.com/#q=counterfeit+ultrafire
According to the "real" UltraFire web pile, they didn't make cells
over 3000 ma-hr, making your 3200 ma-hr cell a genuine counterfeit.


--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On Friday, November 20, 2015 at 12:04:25 PM UTC-5, Jeff Liebermann wrote:
Quoted text here. Click to load it

Genuine counterfeits--insist on nothing less!

And why settle for 8Ah?  All mine are 80Ah.  :-)

Cheers,
James Arthur

Re: Cheap Li-Ion batteries 8000mah on ebay?
On Fri, 20 Nov 2015 16:18:32 -0800 (PST), snipped-for-privacy@yahoo.com
wrote:

Quoted text here. Click to load it


All your batteries are belong to us.
<https://en.wikipedia.org/wiki/All_your_base_are_belong_to_us
You have no chance to survive, make your time.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On a sunny day (Fri, 20 Nov 2015 09:04:58 -0800) it happened Jeff Liebermann

Quoted text here. Click to load it

Wow, did not know about that site.
Sure, from the spelling on the battery it is clear you are not dealing with a real multinational:
 http://panteltje.com/pub/utra_fire_protected_against_almost_everything_IMG_5162.JPG


Quoted text here. Click to load it

But, it gets the work done, if it was made of chewing gum and kept my flashlight working I would be happy too,
even if it had only a picture of Mickey Mouse on it.

I get many things from China that look like 'home made',
for example the 1 Ah lipos with Varta on it, I am still not sure it really _is_ Varta,
but... 300 charge / discharge (90 %) cycles later I see a slight decrease in capacity.
reasonable for a lipo...

Its just a consumable...
Because I did see that decrease, and these need to run 12 hours a day,
(now talking lipo) I bought some of these power packs to test:
  http://panteltje.com/pub/high_power_lipos_IMG_5145.JPG
I still have to solder these in...
It is actually these:
 http://www.ebay.com/itm/151808064280

These ones have _no_ protection unlike the Varta marked ones, so BIG currents may flow.
So... 25 A discharge? Will see, will likely add a fuse.


Re: Cheap Li-Ion batteries 8000mah on ebay?
On Sat, 21 Nov 2015 08:15:30 GMT, Jan Panteltje

Quoted text here. Click to load it

What you are probably buying are 1000 ma-hr 18650 cells marked with
whatever the vendor thinks will sell.  The cell is good enough for
most things, but not if you're trying to squeeze every last coulomb
out of the cell, as in quadcopters or flashlights.  They're probably
just fine for your instrument experiments, eBikes, and vapo-smog
generators.  I'm not sure about the number of charge cycles on these
batteries.  It's my understand (possibly wrong) that cell design can
optimize capacity or charge cycles, but not both.  

Quoted text here. Click to load it

At 90% discharge, you should be killing those batteries.  At what
terminal voltage do you stop brutalizing those batteries?  See Fig 2:
<http://www.mdpi.com/1996-1073/7/9/5995/htm
10% would be about 3.50V.

For extra fun, run a frequency scan of your LiIon battery and watch it
age:
<http://batteryuniversity.com/learn/article/testing_lithium_based_batteries
I haven't done this but plan to throw together something to do it,
some day, later, maybe...

Quoted text here. Click to load it

Money is also a consumable.  Whatever works for you, as long as it
doesn't become a collectable, which is responsible for my mess.

Quoted text here. Click to load it

I use similar batteries, mostly those used by the RC community.
<http://www.hobbyking.com/hobbyking/store/__86__85__Batteries_Accessories-Li_Poly_All_brands_.html
This is my favorite 11.1v battery pack:
<https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct26%472
Yes, I pay extra for the shrink wrap, power connector, balance
charging connector, but don't want to build battery packs (until I get
spot welder).

Quoted text here. Click to load it

The aformentioned favorite 11.1v battery is rated at 25C continuous
discharge:
  25 * 2.2A = 55A
with a maximum charge rate of 5C or:
   5 * 2.2A = 11A
You might as well use a PCB trace as a fuse.  However, you can get
chargers with overcurrent protection:
<http://www.ebay.com/itm/281843079093 3S, 4-5A
<http://www.ebay.com/itm/181749089393 3S, 10-15A



--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On a sunny day (Sat, 21 Nov 2015 09:53:48 -0800) it happened Jeff Liebermann

Quoted text here. Click to load it

Eh, let's see, from asm source:
; Lipo battery cutoff voltage in mV  
#define BATTERY_LOW_CUTOFF_VOLTAGE      D'3100'

; Display will warn at this battery voltage level that battery needs charging
#define BATTERY_LOW_WARNING_VOLTAGE     D'3200'

This is what I measured on the 'Varta' marked lipos:
 
http://panteltje.com/pub/lipo_discharge_curve_low_drop_out_regulator.gif
You will note that from warning at 3.2 V to switch-off at 3.1 V only takes a minute or less...
It crapped out once this week (am not always around to see warnings).
Don't remember the discharge current.

Now that you mention this I will try in a test-setup at a modest current (maybe 1 A)  how long these new ones last.
I like your big heatsink with fan battery test setup.



Quoted text here. Click to load it

The difference at the peak is only about 20/28 or 71%...


Quoted text here. Click to load it

Yes I have something like that from the local RC shop for my laser RC plane:
http://panteltje.com/pub/lipo_jump_starter_IMG_5105.JPG
used it to jump start my scooter :-)


Quoted text here. Click to load it

Yes, well I meant the fuse for accidently shorting it.


Re: Cheap Li-Ion batteries 8000mah on ebay?
On Sat, 21 Nov 2015 19:45:17 GMT, Jan Panteltje

Quoted text here. Click to load it

Here's another way of doing it.  Charge the battery to some voltage
below 4.2v and see how much capacity it has left:
<http://www.powerstream.com/lithium-ion-charge-voltage.htm
Presumably, when it's done charging, the terminal voltage will equal
the charging voltage.  At your 3.1v cutoff, the % of rated charge is
zero.  10% looks to be about 3.75V.

For LiFePO4 cells, 10% is about 3.25V.
<http://www.powerstream.com/lithium-phosphate-charge-voltage.htm

Incidentally, notice how many charges he gets if you charges to
something less the 100% of capacity.

Quoted text here. Click to load it

As I understand it, when the discharge curve hits the knee and starts
to drop off rapidly, it's time to stop charging.

Quoted text here. Click to load it

Don't forget the battery terminal clamp.  
<
http://802.11junk.com/jeffl/LiPo/Ultrafire%2018650%20test.jpg

I was getting really erratic results when I was using a battery holder
like this:
<
http://802.11junk.com/jeffl/NiMH/cba-II.jpg

Use the force.

Quoted text here. Click to load it

<http://www.westmountainradio.com/cba.php
The heat sink and fan are necessary.  I accidentally dumped some loose
junk over the fan, which then stopped.  About 30 mins later, I smelled
smoke.  

If you plan to build your own, please note that the CBA II has a
design defect in that it measures the battery voltage at the wrong end
of the test leads.  At high currents, the voltage drop through the
leads and battery contacts can be substantial.  I wanted to move the
sense wires from inside the device to the battery terminals, but never
finished.

For my test, I used 1.3A because that's what the flashlight I was
testing draws at maximum brightness.  I would expect your counterfeit
cells to look very much like my counterfeit test battery:
<
http://802.11junk.com/jeffl/LiPo/Ultrafire%20LiPo%203000%20ma-hr%2018650%20test.jpg


Quoted text here. Click to load it

You might want to measure how long it will take your fuse to blow with
a partly discharged battery and a not so perfect short, such as a
screwdriver.  A fully charged battery and a good short circuit will
blow most any fuse or fusible link.  However, that's not always the
case when it shorts.  I've had the fuse do nothing while the wiring
got hot enough to melt the insulation.  Fusible links:
<http://www1.cooperbussmann.com/pdf/01e5795a-2857-422e-85c0-62eb8b13d2c5.pdf




--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On a sunny day (Sat, 21 Nov 2015 14:25:34 -0800) it happened Jeff Liebermann

Quoted text here. Click to load it

I have only one lifepo4 cell so far, like this, but different seller):
  http://www.ebay.com/itm/220983787601
it is in a keyboard, I only charged it once.. IIRC in May 2014, it is still working..

I do see prices are now coming down for lifepo4.



Quoted text here. Click to load it

Right, and do not use Chinese Alligator test leads, the copper wire in those is so thin that at 100 mA it drops up to 2 V
for a 50 cm lead!
This has gotten me several times, finally keeping the alligator clips and soldering real wires on it.
Were not even soldered, just sort of pressed against the metal.

  
Quoted text here. Click to load it

Ehh I should have read ahead!


Quoted text here. Click to load it

Or make your own electronic over current switch,
depends on how much you trust your own designs...
:-)
But I think to fuse a 25 A capable lipo battery with a 1 A fast fuse is OK for what I do.


Re: Cheap Li-Ion batteries 8000mah on ebay?
On Sat, 21 Nov 2015 08:15:30 GMT, the renowned Jan Panteltje

Quoted text here. Click to load it

Possibly (probably) fake.  

I replaced the Varta NiCd cells in a car instrument cluster a few
years ago- they lasted more than 20 years!


--sp






--  
Best regards,  
Spehro Pefhany
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On Thu, 19 Nov 2015 15:04:46 +1100, Clifford Heath

Quoted text here. Click to load it

I thought that these *Fire names are just nicknames for cells that
catch fire (when abused).

However, some manufacturers seems to be actually using such real brand
names, perhaps honest, but not so good marketing strategy :-)


Re: Cheap Li-Ion batteries 8000mah on ebay?
On Sat, 21 Nov 2015 10:44:27 +0200, the renowned
snipped-for-privacy@downunder.com wrote:

Quoted text here. Click to load it

Hopefully *only* when abused.  

Quoted text here. Click to load it

It's very difficult to come up with names that don't create unwanted
associations in the mind (of a native speaker). I was helping folks
come up with an English name for a new company last month- the names
that I thought were good were (of course) already taken and most of
the ones they came up with had unpleasant, unfortunate or sexual
connotations that were difficult to explain. Complicated by regulatory
limitations in some markets on what you can call your company, as well
as just simply not being so close as to poach on another's name. There
are companies that do nothing but this: http://www.namelab.com/ , but
doing a thorough job is not cheap. There are surely regional
variations as well as variations from country to country, even those
that nominally use the same language, especially where slang and
association with regional events and entities are involved.  

--sp  



  

--  
Best regards,  
Spehro Pefhany
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On Sat, 21 Nov 2015 13:37:46 -0500, Spehro Pefhany

Quoted text here. Click to load it

Then, there are companies that are cheap, lazy, or both.
A123 battery company was forced to change its name as part of the
buyout deal and became B456:
<http://www.forbes.com/sites/kaipetainen/2013/03/28/battery-company-changes-name-from-a123-to-b456-a-fire-extinguisher/
Apparently, they didn't want to waste any money finding a new name for
essentially a place holder.  Too bad a B456 is actually a fire
extinguisher.  
<http://www.amerexfireextinguishers.com/html/abc_.html
Seeing a pattern here, I Googled for C789 and found a Fluke meter:
<http://en-us.fluke.com/products/all-accessories/fluke-c789.html
Meanwhile, one of the founders of the original A123 company formed a
new battery company, 24M to make cheaper LiIon cells:
<http://24-m.com


--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Cheap Li-Ion batteries 8000mah on ebay?
On 19/11/2015 1:45 PM, Bill Bowden wrote:
Quoted text here. Click to load it

Quoted text here. Click to load it
Chinese mAH are about as well defined as the currency.

It seems that even the better ones quote figures which should be mWH,  
not mAH.  At 3.7 volts, it makes a difference of a factor 3.7, which  
seems about right.

Site Timeline