Charging time for Ultrafire 18650 6800 mAh battery

[Andy]

I would like to find out how long to charge the above battery.

Charger puts out 500 mAh.

Thanks.

[Lasse Langwadt Christensen]

ball park guess 6800mAh/500mA = ~14 hours

[rickman]

Unless this is a D cell or some highly specialized battery chemistry,
there are no 6800 mAh AA cells. Any rechargable with "fire" in the name
is a lie. They are well documented on the web.

--

Rick C

[dca...@krl.org]

On Friday, March 10, 2017 at 7:11:43 PM UTC-5, rickman wrote:

>
> Unless this is a D cell or some highly specialized battery chemistry,
> there are no 6800 mAh AA cells. Any rechargable with "fire" in the name
> is a lie. They are well documented on the web.
>
> --
>
> Rick C

You missed the 18650 in the subject title, But you are right anyway. There are no 6800 mah 18659 batteries. I think the best 18650 batteries are just over 2000 mah.

Dan

[mike]

I'd guess about 3 hours to full charge.
Not to be confused with the ADVERTISED 6800 mAh.

My 4000 mAh Ultrafire cells perform far WORSE
than cells removed from DEAD laptop batteries.

Charging lithium cells safely is not a simple
process.
Assuming your charger is designed to charge those cells,
it will do whatever it does. Rarely do the numbers
on the package give you much useful information.

As a cautionary note...
I bought mine for a quarter at a garage sale, so I don't
know where they came from.
The included charger connects two cells directly in parallel.
If you put in one dead one and a fully charged one,
you may make some serious smoke/fire.

[Jeff Liebermann]

Not enough information to answer. There's more to charging a LiIon
battery than cramming 500 mA (not mA-Hrs) into the battery. The
charger has to know the SoC (state of charge) so that it doesn't
overcharge your battery. It also has to make sure the charger NEVER
goes over 4.2VDC and check if the battery is getting warm. Lots of
things that can go wrong. Some good stuff on charging LiIon:
<http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries>

What you should do is purchase a suitable charger for an 18650 cell.
For example:
<http://www.ebay.com/itm/172543493246>
or a dual charger:
<http://www.ebay.com/itm/291748570741>

Also, your Ultrafire battery is certainly not going to deliver 6500
mA-hrs. My test of an Ultrafire 3000 18650 cell shows that it will
deliver about 800 ma-hr with a 1.3A constant current discharge, which
is what one of my flashlights like to draw.
<http://802.11junk.com/jeffl/LiPo/Ultrafire%20LiPo%203000%20ma-hr%2018650%20test.jpg>
<http://802.11junk.com/jeffl/LiPo/Ultrafire%2018650%20test.jpg
That's a West Mountain Radio CBA-II discharge tester above:
<http://www.westmountainradio.com/cba.php>

Other tests of 18650 cells:
<http://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html>

Notice how the battery capacity drops as the load current increases.
Such cells are normally tested at 20% of their rated capacity. So, a
Panasonic 18650 BD cell, rated at 3000 mA-hr, is tested at 0.61A, and
usually meets the spec sheet claims.

In theory, your Ultrafire 18650 would be tested at 0.20 * 6.8A = 1.3A,
which is exactly what my test graph uses. However, the results were
far from 6800 mA-Hr and instead produced 800 mA-Hr. That rather
suggests that the 6800 mA-Hr number is bogus. In my experience, most
everything with the word "fire" in the name is over-rated.




--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Spehro Pefhany]

There are some that are as good as 3500mAh +/-, but 'Ultrafire' is
known *not* to be a source of such product.

Your estimate of 1800-2000 is probably reasonably good. I've been
meaning to set up the logger and electronic load but it probably won't
happen soon.

--sp


--
Best regards,
Spehro Pefhany

[Neon John]

On Fri, 10 Mar 2017 15:47:15 -0800 (PST), Andy
<andrewke...@gmail.com> wrote:

Several things. There is no such thing as a 6800 mah 18650 cell.
That's chinese lying again. If you go to http://www.dx.com (a chinese
vendor of among other things, flashlights, batteries and parts),
you'll find probably a hundred different 18650 batteries for sale with
the claimed mah as the page title and the actual tested mah in
parenthesis.

The very best 18650 that we consumers can buy is the Panasonic "red
tube" 3200 mah cell. Not only is the spec real but the cell has a
very low impedance which makes the cell useful in hotrod flashlights
that I make as a hobby.

Charging. Do NOT try to charge a LiIon cell by time. The best you
will do is destroy the cell. The worst you will do is cause a
violent, rocket-like fire!!!

LiIon cells are charged to a specified termination voltage and then
the charger turns off. There is a tradeoff between life and capacity,
and termination voltage. I charge my Panasonics to 4.20 volts. That
gives me maximum capacity but reduces the life. I don't care much
about life. I can buy more.

Here they are:

http://www.dx.com/p/panasonic-ncr18650bf-super-max-3-7v-3400mah-rechargeable-18650-li-ion-battery-red-356976

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address

[Robert Baer]

Most batteries are specified to be (safely) charged at C/20, some at
C/10.

[Jeff Liebermann]

Wrong. The *DISCHARGE* rate is C/20 for the sole purpose of providing
a uniform test of battery capacity in ma-hr. If one charged a 3000
ma-hr cell at that rate, it would take over 20 hrs for this battery to
be fully charged. Obviously, that's not happening.

Maximum charge and discharge current rating vary by battery chemistry
and construction. As an example, a 2 cell 1000 ma-hr battery pack:
<https://hobbyking.com/en_us/turnigy-1000mah-2s-30c-lipo-pack.html>
is rated at:
30C (30 amps) constant discharge
40C (40 amps) intermittent discharge
2C (2 amps) maximum charge rate.

[Jasen Betts]

On 2017-03-15, Jeff Liebermann <je...@cruzio.com> wrote:
> On Tue, 14 Mar 2017 22:52:52 -0800, Robert Baer
><rober...@localnet.com> wrote:
>
>>Andy wrote:
>>> I would like to find out how long to charge the above battery.
>>>
>>> Charger puts out 500 mAh.
>>>
>>> Thanks.
>
>> Most batteries are specified to be (safely) charged at C/20, some at
>>C/10.
>
> Wrong. The *DISCHARGE* rate is C/20 for the sole purpose of providing
> a uniform test of battery capacity in ma-hr. If one charged a 3000
> ma-hr cell at that rate, it would take over 20 hrs for this battery to
> be fully charged. Obviously, that's not happening.

C/20 is a safe constant charge current for NiMH batteries if you don't
have a fast charger, C/10 for NiCd, neither applies to Lead-Acid or
lithium.

--
This email has not been checked by half-arsed antivirus software

[k...@notreal.com]

On Wed, 15 Mar 2017 00:28:00 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Tue, 14 Mar 2017 22:52:52 -0800, Robert Baer
><rober...@localnet.com> wrote:
>
>>Andy wrote:
>>> I would like to find out how long to charge the above battery.
>>>
>>> Charger puts out 500 mAh.
>>>
>>> Thanks.
>
>> Most batteries are specified to be (safely) charged at C/20, some at
>>C/10.
>
>Wrong. The *DISCHARGE* rate is C/20 for the sole purpose of providing
>a uniform test of battery capacity in ma-hr. If one charged a 3000
>ma-hr cell at that rate, it would take over 20 hrs for this battery to
>be fully charged. Obviously, that's not happening.

Read what he wrote. A C/20 *charge* is safe. A C or 2C or even 10C
charge might be possible but you have to be really careful.

[Clifford Heath]

On 12/03/17 17:17, Spehro Pefhany wrote:
> On Fri, 10 Mar 2017 16:38:37 -0800 (PST), the renowned
> "dca...@krl.org" <dca...@krl.org> wrote:
>> On Friday, March 10, 2017 at 7:11:43 PM UTC-5, rickman wrote:
>>> Unless this is a D cell or some highly specialized battery chemistry,
>>> there are no 6800 mAh AA cells. Any rechargable with "fire" in the name
>>> is a lie. They are well documented on the web.

>> You missed the 18650 in the subject title, But you are right anyway. There are no 6800 mah 18659 batteries. I think the best 18650 batteries are just over 2000 mah.

> There are some that are as good as 3500mAh +/-

Panasonic make them. They just recently improved from 3400mAh,
as tested by a night-hiking mate of mine.

> Your estimate of 1800-2000 is probably reasonably good.

Unless you get repackaged spent cells, which *fire is known for.
Then you're lucky to get 800mAh.

Clifford Heath.

[Jeff Liebermann]

Please note that the title of this thread is "Charging time for
Ultrafire 18650 6800 mAh battery". To the best of my limited
knowledge, neither NiMH, NiCd, lead-acid, or carbon zinc batteries are
available in an 18650 form factor or are sold under the name of
"Ultrafire". However, you're wrong again about NiMH "safe" charge
rate. The NiMH chargers that I own (Maha, iMax B6, Sanyo Eneloop, etc
all use a negative dV/dT slope to detect EoC (end-o-charge). The
charge rate varies, but the average is somewhere between 0.5C and
1.0C.

Charging NiMH cells at C/20 is considered a "slow charge" and is a
great way to kill a NiMH battery because of the lack of a negative
dV/dT slope to signal EoC:
<http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride>
"It is difficult, if not impossible, to slow charge a NiMH
battery. At a C rate of 0.1C to 0.3C, the voltage and temperature
profiles do not exhibit defined characteristics to trigger
full-charge detection, and the charger must depend on a timer.
Harmful overcharge can occur when charging partially or fully
charged batteries, even if the battery remains cold."

[carlon...@gmail.com]

how many hours to charge a 18650?please be inform me

[DecadentLinuxUserNumeroUno]

carlon...@gmail.com wrote in news:89fccd51-9ff3-425b-acdb-
d4509c...@googlegroups.com:

> how many hours to charge a 18650?please be inform me
>

There is no such thing as an 18650 that can do 6800mAh.

But as far as a standard 18650, which is about all that can be packed
into one, is on google.


Google is you friend.
I found charging tables on this page:

https://lygte-info.dk/info/BatteryChargePercent%20UK.html

[Rheilly Phoull]

On 24/11/2018 9:48 am, carlon...@gmail.com wrote:
> how many hours to charge a 18650?please be inform me
>

1

[DecadentLinuxUserNumeroUno]

carlon...@gmail.com wrote in news:89fccd51-9ff3-425b-acdb-
d4509c...@googlegroups.com:

> how many hours to charge a 18650?please be inform me
>

Look at the specs on this data sheet for a product.

There is a nice data sheet for that battery.

Yours will be similar.

http://www.crazell.com/product/sanyo-ur18650aa/

[k...@notreal.com]

On Fri, 23 Nov 2018 17:48:51 -0800 (PST), carlon...@gmail.com
wrote:

>how many hours to charge a 18650?please be inform me

How do you know your battery is 6800mAh? Did Amazon or, even better
yet, Alibaba tell you it was 6800mAh? (This should be good).

[tabb...@gmail.com]

On Saturday, 24 November 2018 01:48:55 UTC, carlon...@gmail.com wrote:
> how many hours to charge a 18650?please be inform me

If it's 1Ah (1000mAh) then 1A for 1 hr, or 1/2A 2 hrs etc.
If it's 2Ah, double that etc


NT

[TTman]

Or ages and ages with a USB driven charger...

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[Robert Roland]

On Fri, 23 Nov 2018 22:21:43 -0500, k...@notreal.com wrote:

>How do you know your battery is 6800mAh? Did Amazon or, even better
>yet, Alibaba tell you it was 6800mAh?

Strangely, the 18650 seems to have a peculiar property where it gets
cheaper as the capacity increases. You can get 12 Ah (12,000 mAh)
cells on Ebay for less than two bucks these days.

There are plenty of videos on Youtube showing people cutting these
cells open to reveal what is inside. In some cases, an itsy bitsy LiPo
cell and a bunch of sand.

Ebay does nothing to stop the swindlers, even after having been
notified.
--
RoRo

[k...@notreal.com]

On Sat, 24 Nov 2018 16:33:57 +0100, Robert Roland <fa...@ddress.no>
wrote:

>On Fri, 23 Nov 2018 22:21:43 -0500, k...@notreal.com wrote:
>
>>How do you know your battery is 6800mAh? Did Amazon or, even better
>>yet, Alibaba tell you it was 6800mAh?
>
>Strangely, the 18650 seems to have a peculiar property where it gets
>cheaper as the capacity increases. You can get 12 Ah (12,000 mAh)
>cells on Ebay for less than two bucks these days.

Wow, that's surprising. The additional ink costs something. ;-)

>There are plenty of videos on Youtube showing people cutting these
>cells open to reveal what is inside. In some cases, an itsy bitsy LiPo
>cell and a bunch of sand.
>
>Ebay does nothing to stop the swindlers, even after having been
>notified.

Believe nothing being sold on these sites. Batteries seem to be the
absolute worst. It can be difficult to find honest battery suppliers.
Buying directly from the manufacturers is almost impossible, even if
your volumes are quite large (been there, haven't been able to do
that).

[Jeff Liebermann]

On Fri, 23 Nov 2018 17:48:51 -0800 (PST), carlon...@gmail.com
wrote:

>how many hours to charge a 18650? please be inform me

Ultrafire 18650 batteries are junk. Here's the discharge curve of an
allegedly 3000ma-hr Ultrafire 18650 cell at 1.3A:
<http://www.learnbydestroying.com/jeffl/LiPo/Ultrafire%20LiPo%203000%20ma-hr%2018650.jpg>
<http://www.learnbydestroying.com/jeffl/LiPo/Ultrafire%2018650%20test.jpg>
Looks like it's really only good for 800ma-hr capacity. You would
need three or four of these cells to equal the capacity of a real
18650 cell.

For fun, I crammed the blue Ultrafire 3000 cell in the photo into a
handy flashlight and ran it until the light quit. No runtime number
here because the battery was partly charged. I then crammed it into a
XTAR VC2 charger and started the timer. The charger indicated it was
charging at 500ma rate. I missed when it actually proclaimed the
battery as being fully charged, but my guess(tm) is 70 minutes. The
theoretical charge time at 500ma would be:
800 ma-hr / 500 ma = 1.6 hrs

One problem with over-rated and junk batteries is reconciling the
discrepancy between the over-inflated capacity, and the real battery
capacity. The problem is that the recommended charging rate is about
0.6C. For the Ultrafire 18650, that would be:
3000 * 0.6 = 1800 ma (using advertised capacity)
or
800 * 0.6 = 480 ma (using measured capacity)
If I tried charging this Ultrafire cell at 1800 ma, I would be
overcharging it at 2.3C. Therefore, if you must buy junk batteries on
eBay, take the time to measure the capacity and use the measured value
to establish the charging rate.

For more info, I suggest you dig through:
<https://lygte-info.dk>
<https://www.candlepowerforums.com/vb/forum.php>
<http://budgetlightforum.com/forum>
<https://batteryuniversity.com/index.php/learn/article/charging_lithium_ion_batteries>

Drivel and status report: Just escaped from the hospital. Laser
lithotripsy to remove one kidney stone failed. I go back in a week or
so to try again. A month later, I repeat the ceremony to remove the
other boulder. I'll be rather scarce in the forums and mailing lists
until I'm recovered.

[Carl]

On 11/24/18 Jeff Liebermann wrote:
>Drivel and status report: Just escaped from the hospital. Laser
>lithotripsy to remove one kidney stone failed. I go back in a week or
>so to try again. A month later, I repeat the ceremony to remove the
>other boulder. I'll be rather scarce in the forums and mailing lists
>until I'm recovered.

Hope everything goes well from now on.

--
Regards,
Carl Ijames

[tabb...@gmail.com]

Good luck with that one :/


NT

[boB]

Yes, good health to you for new years !

[Mike Perkins]

On 24/11/2018 19:33, Jeff Liebermann wrote:

<snip>

> Drivel and status report: Just escaped from the hospital. Laser
> lithotripsy to remove one kidney stone failed. I go back in a week or
> so to try again. A month later, I repeat the ceremony to remove the
> other boulder. I'll be rather scarce in the forums and mailing lists
> until I'm recovered.

First of all my sympathies.

Can I ask why the procedure failed first time?


--
Mike Perkins
Video Solutions Ltd
www.videosolutions.ltd.uk

[Jeff Liebermann]

On Mon, 26 Nov 2018 03:33:59 +0000, Mike Perkins <sp...@spam.com>
wrote:

>On 24/11/2018 19:33, Jeff Liebermann wrote:
><snip>
>> Drivel and status report: Just escaped from the hospital. Laser
>> lithotripsy to remove one kidney stone failed. I go back in a week or
>> so to try again. A month later, I repeat the ceremony to remove the
>> other boulder. I'll be rather scarce in the forums and mailing lists
>> until I'm recovered.

>First of all my sympathies.

Thanks, and also my thanks to others who also offered their
sympathies. However, none is required. I plan to get through this
mess and return to normal eventually. The trick is not about modern
medicine or money. It's about surviving bad scheduling, hospital
super-bugs, medical mistakes, and oddly about practicing medicine from
a lawsuit inspired medical cookbook. So far they've only tried to
kill me once (by accident), but most everything else is going fairly
smoothly.

>Can I ask why the procedure failed first time?

Laser lithotripsy. The laproscope is about 5.5mm wide. They were
only able to enlarge the entry hole from the ureter to the kidney to
about 3mm dia. (Note that stents are normally sized by circumference,
not diameter). Any larger, and I started bleeding profusely due to my
being on blood thinner (Plavix). The surgeon was unable to get the
laser into the kidney. So, they left a 2mm dia stent in place to
eliminate the painful backpressure, patched me up, dropped the blood
thinners form my growing prescription list, released me on
Thanksgiving evening, and asked me to call on Monday for round two. My
best guess(tm) is the next attempt will be using PCNL:
"How are Kidney Stones Treated?"
<https://www.urologyhealth.org/urologic-conditions/kidney-stones/treatment>

I had the same laser lithotripsy procedure 10 years ago for removing a
previous boulder. It works, I recommend it, but has some limitations.
The big one is that it only breaks up the boulder, and does NOT remove
the debris. That took about 10 days and was Level 10 agony for the
entire period. The not so big limitation is that running a laproscope
through a rather sensitive part of my anatomy can be rather painful
when later trying to urinate. I've repeatedly asked for some 5%
lidocaine topical ointment to deaden the nerves, which has been
repeatedly "forgotten". I wanted to mix my own using some illegal
cocaine, but failed to find my 30 year old stash.

If you want more details, email please.

[Mike Perkins]

On 26/11/2018 04:19, Jeff Liebermann wrote:
> On Mon, 26 Nov 2018 03:33:59 +0000, Mike Perkins <sp...@spam.com>
> wrote:
>
>> On 24/11/2018 19:33, Jeff Liebermann wrote:
>> <snip>
>>> Drivel and status report: Just escaped from the hospital. Laser
>>> lithotripsy to remove one kidney stone failed. I go back in a week or
>>> so to try again. A month later, I repeat the ceremony to remove the
>>> other boulder. I'll be rather scarce in the forums and mailing lists
>>> until I'm recovered.
>
>> First of all my sympathies.
>
> Thanks, and also my thanks to others who also offered their
> sympathies. However, none is required. I plan to get through this
> mess and return to normal eventually. The trick is not about modern
> medicine or money. It's about surviving bad scheduling, hospital
> super-bugs, medical mistakes, and oddly about practicing medicine from
> a lawsuit inspired medical cookbook. So far they've only tried to
> kill me once (by accident), but most everything else is going fairly
> smoothly.

I was speaking from experience from 2 failed laser lithotripsy and one
successful, and in the mean time two rounds of SWL. This went on for
months! Mine was 11mm.

>> Can I ask why the procedure failed first time?
>
> Laser lithotripsy. The laproscope is about 5.5mm wide. They were
> only able to enlarge the entry hole from the ureter to the kidney to
> about 3mm dia. (Note that stents are normally sized by circumference,
> not diameter). Any larger, and I started bleeding profusely due to my
> being on blood thinner (Plavix). The surgeon was unable to get the
> laser into the kidney. So, they left a 2mm dia stent in place to
> eliminate the painful backpressure, patched me up, dropped the blood
> thinners form my growing prescription list, released me on
> Thanksgiving evening, and asked me to call on Monday for round two. My
> best guess(tm) is the next attempt will be using PCNL:
> "How are Kidney Stones Treated?"
> <https://www.urologyhealth.org/urologic-conditions/kidney-stones/treatment>

I'm aware the ureter is a very sensitive and easily torn, so I can
understand the reluctance to do anything to compromise the small tube.

> I had the same laser lithotripsy procedure 10 years ago for removing a
> previous boulder. It works, I recommend it, but has some limitations.
> The big one is that it only breaks up the boulder, and does NOT remove
> the debris. That took about 10 days and was Level 10 agony for the
> entire period. The not so big limitation is that running a laproscope
> through a rather sensitive part of my anatomy can be rather painful
> when later trying to urinate. I've repeatedly asked for some 5%
> lidocaine topical ointment to deaden the nerves, which has been
> repeatedly "forgotten". I wanted to mix my own using some illegal
> cocaine, but failed to find my 30 year old stash.
>
> If you want more details, email please.

LOL - been there and got the T-shirt!

I have heard women say the pain is as bad as childbirth.

So when I'm told about the pain of childbirth I say that I've heard from
ladies it's on par with kidney stones. Naturally when they say 'have you
had a child', I counter with 'have you had a kidney stone'!

[007chava...@gmail.com]

I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so my question is, is this battery really has 6800 mah? If it is real the I used 4 battery's it means 4X6850=27200mah is that true. Please tell me someone...

[tabb...@gmail.com]

On Saturday, 8 December 2018 18:27:26 UTC, 007chava...@gmail.com wrote:
> I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so my question is, is this battery really has 6800 mah? If it is real the I used 4 battery's it means 4X6850=27200mah is that true. Please tell me someone...

No.

[gnuarm.del...@gmail.com]

On Saturday, December 8, 2018 at 1:27:26 PM UTC-5, 007chava...@gmail.com wrote:
> I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so my question is, is this battery really has 6800 mah? If it is real the I used 4 battery's it means 4X6850=27200mah is that true. Please tell me someone...

Are you connecting the batteries in parallel or in series? If you connect batteries in series the voltages add, but the current rating (mAHr) remains the same. If you connect the batteries in parallel the voltage is the same, but the currents are added.

None of this says anything about the accuracy of the claimed 6800 mAHr rating of the Ultrafire cells.

Rick C.

Tesla referral code - https://ts.la/richard11209

[bill....@ieee.org]

On Monday, November 26, 2018 at 3:18:58 PM UTC+11, Jeff Liebermann wrote:
> On Mon, 26 Nov 2018 03:33:59 +0000, Mike Perkins <sp...@spam.com>
> wrote:
>
> >On 24/11/2018 19:33, Jeff Liebermann wrote:
> ><snip>
> >> Drivel and status report: Just escaped from the hospital. Laser
> >> lithotripsy to remove one kidney stone failed. I go back in a week or
> >> so to try again. A month later, I repeat the ceremony to remove the
> >> other boulder. I'll be rather scarce in the forums and mailing lists
> >> until I'm recovered.
>
> >First of all my sympathies.
>
> Thanks, and also my thanks to others who also offered their
> sympathies. However, none is required. I plan to get through this
> mess and return to normal eventually. The trick is not about modern
> medicine or money. It's about surviving bad scheduling, hospital
> super-bugs, medical mistakes, and oddly about practicing medicine from
> a lawsuit inspired medical cookbook. So far they've only tried to
> kill me once (by accident), but most everything else is going fairly
> smoothly.
>
> >Can I ask why the procedure failed first time?
>
> Laser lithotripsy.

My sympathy too. Laser lithotripsy didn't work for me either (as you may recall) but the ultra-sound lithotriptor did.

It did leave me feeling that I'd been punched in the back by something substantial, but that was strictly soft-tissue damage and stopped worrying me after a day lying down and taking as much iboprufen as the label suggests is prudent.

The ultra sound system does seem to break up kidney stones pretty thoroughly.

--
Bill Sloman, Sydney

[Jeff Liebermann]

On Sat, 8 Dec 2018 10:27:21 -0800 (PST), 007chava...@gmail.com
wrote:

>I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so my question is, is this battery really has 6800 mah? If it is real the I used 4 battery's it means 4X6850=27200mah is that true. Please tell me someone...

No. They are junk. My measurements on a single UltraFire 18650 cell
shows about 800 ma-hr. Google shows 33 posts by 23 authors all of
which indicate that the 6800 ma-hr printed rating is a fabrication and
impossible to achieve with even the best consumer grade LiIon 18650
cells available. At best, you might be able to deliver about 2500
ma-hr.

Please read or re-read my original reply to your question, or to
someone who may be nym shifting a gmail address:
<https://groups.google.com/d/msg/sci.electronics.design/bRStFgNxNJQ/Aq-7ILWxAQAJ>

[k...@notreal.com]

On Sat, 8 Dec 2018 10:27:21 -0800 (PST), 007chava...@gmail.com
wrote:

>I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so my question is, is this battery really has 6800 mah? If it is real the I used 4 battery's it means 4X6850=27200mah is that true. Please tell me someone...

No 18650 LiIon cell is 6800mAh. Half that would be dreaming.

[Jasen Betts]

On 2018-12-08, 007chava...@gmail.com <007chava...@gmail.com> wrote:
> I have buy a ultrafire 18650 6800mah battery for making DIY power
> bank, so my question is, is this battery really has 6800 mah?

no it's a fake.

--
When I tried casting out nines I made a hash of it.

[Jeff Liebermann]

On Sat, 8 Dec 2018 19:31:04 -0800 (PST), bill....@ieee.org wrote:

>On Monday, November 26, 2018 at 3:18:58 PM UTC+11, Jeff Liebermann wrote:
>> On Mon, 26 Nov 2018 03:33:59 +0000, Mike Perkins <sp...@spam.com>
>> wrote:
>>
>> >On 24/11/2018 19:33, Jeff Liebermann wrote:
>> ><snip>
>> >> Drivel and status report: Just escaped from the hospital. Laser
>> >> lithotripsy to remove one kidney stone failed. I go back in a week or
>> >> so to try again. A month later, I repeat the ceremony to remove the
>> >> other boulder. I'll be rather scarce in the forums and mailing lists
>> >> until I'm recovered.
>>
>> >First of all my sympathies.
>>
>> Thanks, and also my thanks to others who also offered their
>> sympathies. However, none is required. I plan to get through this
>> mess and return to normal eventually. The trick is not about modern
>> medicine or money. It's about surviving bad scheduling, hospital
>> super-bugs, medical mistakes, and oddly about practicing medicine from
>> a lawsuit inspired medical cookbook. So far they've only tried to
>> kill me once (by accident), but most everything else is going fairly
>> smoothly.
>>
>> >Can I ask why the procedure failed first time?
>>
>> Laser lithotripsy.

>My sympathy too. Laser lithotripsy didn't work for me either (as you
>may recall) but the ultra-sound lithotriptor did.

I can't do ESWL (extracorporeal shock wave lithotripsy). The left
rock decided it was time to leave the kidney and ended up stuck in the
ureter. The CT scan also showed that it's much too dense at 1500 HU
(Hounsfield Units) to fracture with ultrasound. Methinks the limit is
900 HU. I'm scheduled for another CT scan on Monday, and if the stone
cooperates, the doctors will be playing laser tag with it on Tuesday.
There's a fair chance that I may have already passed the left stone
but have no way to tell because I have a stent installed to relieve
the back pressure and therefore no pain.

Stone Size, Density Matter
<https://www.renalandurologynews.com/news/stone-size-density-matter/article/30140/>

>It did leave me feeling that I'd been punched in the back by something
>substantial, but that was strictly soft-tissue damage and stopped
>worrying me after a day lying down and taking as much iboprufen as
>the label suggests is prudent.

I was taking vicodin for the pain. It still hurts, but I didn't care.
Imagine a constipated zombie at the keyboard.

>The ultra sound system does seem to break up kidney stones pretty thoroughly.

Only if the stones are not very dense. My stones don't qualify.

[bilou]

gnuarm.del...@gmail.com a exprimé avec précision :

> On Saturday, December 8, 2018 at 1:27:26 PM UTC-5, 007chava...@gmail.com
> wrote:
>> I have buy a ultrafire 18650 6800mah battery for making DIY power bank, so
>> my question is, is this battery really has 6800 mah? If it is real the I
>> used 4 battery's it means 4X6850=27200mah is that true. Please tell me
>> someone...
>
> Are you connecting the batteries in parallel or in series? If you connect
> batteries in series the voltages add, but the current rating (mAHr) remains
> the same. If you connect the batteries in parallel the voltage is the same,
> but the currents are added.

+1
It is strange that someone without such basic knowledge atempt DIY with
Li/ion batteries.
I hope you have a good insurance.

[Clifford Heath]

Buy some genuine Panasonic NCR cells. They test at their spec, 3400mAh.
You'll think you're dreaming, but it's real. :)

[gnuarm.del...@gmail.com]

On Sunday, December 9, 2018 at 12:14:24 AM UTC-5, Jeff Liebermann wrote:
>
> I can't do ESWL (extracorporeal shock wave lithotripsy). The left
> rock decided it was time to leave the kidney and ended up stuck in the
> ureter. The CT scan also showed that it's much too dense at 1500 HU
> (Hounsfield Units) to fracture with ultrasound. Methinks the limit is
> 900 HU. I'm scheduled for another CT scan on Monday, and if the stone
> cooperates, the doctors will be playing laser tag with it on Tuesday.
> There's a fair chance that I may have already passed the left stone
> but have no way to tell because I have a stent installed to relieve
> the back pressure and therefore no pain.

The back pressure is from urine backed up behind the stone. The stent is a device to widen the ureter. If the stone is still blocking the ureter the stent can't pass the urine around it... can it?

> Stone Size, Density Matter
> <https://www.renalandurologynews.com/news/stone-size-density-matter/article/30140/>
>
> >It did leave me feeling that I'd been punched in the back by something
> >substantial, but that was strictly soft-tissue damage and stopped
> >worrying me after a day lying down and taking as much iboprufen as
> >the label suggests is prudent.
>
> I was taking vicodin for the pain. It still hurts, but I didn't care.
> Imagine a constipated zombie at the keyboard.

Yeah, I remember that feeling in the ER a couple of times. When they sent me into the x-ray lab for an IVP the dye backing up behind the stone would both make it start hurting all over again and push the stone out of the kidney. They've never actually x-rayed one in the kidney until the one I had to have lipsotrypsied. I think it's been nine in total.

> >The ultra sound system does seem to break up kidney stones pretty thoroughly.
>
> Only if the stones are not very dense. My stones don't qualify.

Mine didn't get broken up so thoroughly, but enough that the pieces eventually passed. The doctor was an older guy who didn't give a shit anymore and worked the system to his own advantage. He first tried going in after the stone through the ureter but the stone was too large to take out that way. He claimed he couldn't see that on the x-ray. I'm calling BS on that. He just wanted to bill for the procedure.

Later he was treating my cousin and I heard the phone call where my cousin needed his weekly prescription of pain killer to be renewed and the doc told him he saw where my cousin has scheduled the procedure with someone else who would schedule it sooner. My cousin wasn't going to get his pain meds unless he rescheduled with this doctor! This was on a Saturday when there was zero chance of getting a prescription from any other doctor. What a shit! The hospital has a new wing named after that doc now.

[k...@notreal.com]

On Sun, 9 Dec 2018 16:53:38 +1100, Clifford Heath <no....@please.net>
wrote:

Got a datasheet? 26650s, maybe, but 18650s?

[Jeff Liebermann]

<https://www.batteryspace.com/prod-specs/NCR18650B.pdf>
Rated Capacity Min 3200 mAh at 20C
Capacity Min 3250 mAh at 25C
Typ 3350 mAh at 25C

<https://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html>
Scroll down to the various capacity tests. Plenty of cells that test
well above 3000 ma-hr. However, none are even close to 6800 ma-hr.
Also note that the Ultrafire BCR18650 "4000 ma-hr rated" cell is
included in the testing showing the highest internal resistance of all
the cells tested. Yech.

[Clifford Heath]

Better still, a good friend who thinks it's fun to build automated
testers, and has tested several hundred cells. Given the amount of his
life he spends doing epic day-night hikes (60-170km without stopping,
and breaking speed records in his 60+yr age group) and his 40-year
career designing, building and installing satellite ground station
hardware, I tend to trust his measurements more than I'd trust a data sheet.

Clifford Heath.

[Johnny B Good]

All of these Chinese 18650 Ultrafire cells are fakes. The world record
breaking capacity that Panasonic have managed to achieve in this size of
Lithium cell, stands at 3600mAH. Genuine 18650s are more typically 1200
to 2200mAH.

The very first of these Ultrafire fakes started off several years ago
with a capacity claim for 3600mAH, matching the industry leader and
subsequent cons have simply kept inflating the capacity claims in the
hope of enticing yet more technically clueless consumers into buying such
fake goods.

There are plenty of youtube videos demonstrating the abysmal capacity,
often fake cells with a much lower capacity and cheaper cell mounted
inside with perhaps a bit of gravel to make up for the expected weight of
a genuine article.

<https://www.youtube.com/watch?v=gGF9DZcBric> makes a good starting point
for your youtube odyssey into the murky world of Chinese 18650 fakes.
Enjoy!

--
Johnny B Good