Cheap Li-Ion batteries 8000mah on ebay?

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..

formatting link

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

--- news://freenews.netfront.net/ - complaints: snipped-for-privacy@netfront.net ---

Reply to
Bill Bowden
Loading thread data ...

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

Reply to
Clifford Heath

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.

Reply to
Adrian Jansen

Run away. The capacity is certainly way overstated.

Also, typically this type of supplier will cheaply airmail their shoddy lithium cells by lying about the package contents.

It's only a matter of time before an aircraft is taken down by this kind of B.S.

--sp

--
Best regards,  
Spehro Pefhany 
 Click to see the full signature
Reply to
Spehro Pefhany

y

h =

=

=

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.

AAOSw14xWKZ1t

ely

es,

Reply to
David Eather

On a sunny day (Thu, 19 Nov 2015 01:46:11 -0800) it happened mike wrote in :

Well I really do not know,

2 years ago I posted this here
formatting link
$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:
formatting link
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.

Reply to
Jan Panteltje

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  wrote in news:n2kb4r$dcb$1 news.datemas.de: 

> Path: eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!weretis.net!feeder4.news.weretis.net!newsfeed.datemas.de!news.datemas.de!.POSTED!not-for-mail 
 Click to see the full signature
Reply to
John Doe

You need to exercise extreme discretion. Think "brand-name" and "reputable seller". That is a no-brainer when buying such items from Fleabay. Even so when buying from Amazon, Amazon allows counterfeit sellers left and right.

Reply to
John Doe

On a sunny day (Thu, 19 Nov 2015 13:45:54 -0000 (UTC)) it happened John Dodo wrote in :

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?

Reply to
Jan Panteltje

Yes, that seems about right mWH instead of mAH. I went shopping at Fry's today and couldn't find any LI batteries over 2500mAH and they were 12 bucks each. I did see a new item I hadn't seen before. A 10,000 mAH 'D' NiMh cell for 10 bucks. It was in a package of 2 for $19.95. But I already have several 4000 mAH Ni-Cad 'D' cells that still work. I see a lot of used cell phone batteries at swap meets for $1 each, so I could parallel 2 or 3 to get a higher capacity. . . .

--- news://freenews.netfront.net/ - complaints: snipped-for-privacy@netfront.net ---

Reply to
Bill Bowden

Some batteries of this brand name are reviewed and dissassembled on thi website:

formatting link
UK.html

They don't come off well. Some samples had evidence of pre-use in other application formats.

RL

Reply to
legg

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.

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

Clifford Heath.

Reply to
Clifford Heath

Yes, but was it a real or counterfeit UltraFire battery? 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     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
 Click to see the full signature
Reply to
Jeff Liebermann

I mistakedly bought a couple 18650 Ultraf*re batteries- far less than marked capacity- I dissected one- it was not a used cell, just poorly made and significantly lighter than a good one from a reputable manufacturer.

It's kind of interesting when you open them up- the energy is still in there, of course, and bits will spark and smoke when you breach the film separator barrier.

--sp

--
Best regards,  
Spehro Pefhany 
 Click to see the full signature
Reply to
Spehro Pefhany

It looks like there was once a valid UltraFire source that was either compromised or cloned up the wazoo. Prices don't look unreasonably low for some offerings, by chemistry and size but the mAH ratings are off the wall - might read as WHr - would make more sense.

When the polymer protective layer breaks on an internally protected cell contact (permanently), there's often energy stored in the dead cell. The protection method wass unpopular, as the polymer seemed unpredictable with age and environment, producing premature opencircuits.

On disassembly, this remenant can result in spontaneous combustion.

I disassembled these things under water, when I had to. Once a useful source of plated stamped copper mesh. I'm not so sure all that free lithium is good for you, unless prescribed by local MH Professionals.

RL

Reply to
legg

Genuine counterfeits--insist on nothing less!

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

Cheers, James Arthur

Reply to
dagmargoodboat

All your batteries are belong to us. You have no chance to survive, make your time.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
 Click to see the full signature
Reply to
Jeff Liebermann

On a sunny day (Fri, 20 Nov 2015 09:04:58 -0800) it happened Jeff Liebermann wrote in :

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:

formatting link

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:

formatting link
I still have to solder these in... It is actually these:
formatting link

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.

Reply to
Jan Panteltje

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 :-)

Reply to
upsidedown

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.

At 90% discharge, you should be killing those batteries. At what terminal voltage do you stop brutalizing those batteries? See Fig 2:

10% would be about 3.50V.

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

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

I use similar batteries, mostly those used by the RC community. This is my favorite 11.1v battery pack: 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).

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: 3S, 4-5A 3S, 10-15A

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
 Click to see the full signature
Reply to
Jeff Liebermann

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.