Re: OT: Where do I buy battery cells?

[vordoo]

Thanks Michael,

Appreciate your input. I hope I wasn't understood as advocating: Go, 
D.I.Y, replace any battery-cell in any battery pack, with whatever 
equipment you may have hanging around your home-garage.


But...
FYI, The best forum dealing with battery repair, is not in Russian, it 
maybe one of the best, but not the best ;-)


That been said,
I'm on the lookout for battery-cells for my projects & will appreciate 
any info on where they can be safely bought -- i.e.: Get what you have 
thought you have ordered.


Thanks,
:-)

On 2013-11-16 05:29, Michael Vasiliev wrote:

On 11/08/2013 05:00 PM, vordoo wrote:

Hi,

Where can I buy battery cells to rebuild a battery pack?
I would have to recommend against doing this yourself unless you want 
to make a significant investment in equipment and open a small business.


Here is why:
1) You need to buy batteries in bulk (hundred



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Re: OT: Where do I buy battery cells?

[Michael Vasiliev]

  
  
On 11/08/2013 05:00 PM, vordoo wrote:


  
  
  Hi,
  
  Where can I buy battery cells to rebuild a battery pack?

I would have to recommend against doing this yourself unless you
want to make a significant investment in equipment and open a small
business.

Here is why:
1) You need to buy batteries in bulk (hundreds) then charge and
discharge them with calibration equipment, then select enough
batteries with equal characteristics to fit the pack being rebuilt.
Just picking 6 to 9 random batteries from a batch does not work,
they charge and discharge in groups and have to do that equally or
they will overheat. In that case, tripping the alarm at the
controller, rendering the pack unusable, is the lucky scenario. For
other scenarios, see "soldering" below.

2) Soldering the batteries together will not work, for three
reasons:
I) Each one has a fuse/vent on top that cannot withstand high
temperature.
II) The cells degrade, rapidly and irreversibly, when heated with a
soldering iron above 50C. Typical soldering occurs at about 225C.
III) Further heating causes an oxygen breach and fire at least,
though explosion is a very, very possible outcome for cells of this
capacity.

YOU DO NOT DO THAT. NO, SERIOUSLY, DON'T. 
(If you still decide to do that, please do share the story here,
both as a warning to others and for our sick entertainment, once and
if you get out of the hospital)

You will need a spot welder station, but not just any spot welder
but one that does not breach batteries when welding them AND have
the contacts on a small enough distance that allow actual welding on
area of about 5mm AND making the welds that are able to pass the
current required. Yes, this is the station with electronic
charge/discharge control, about $2200 used. OR YOU CAN BUILD ONE AND
BLOW UP YOUR HOUSE. Welding the pack together is done with a nickel
strip which you'll have to buy in bulk. No, cold connectors will not
work.

3) Repacking batteries changes the overall characteristics of the
pack, you have to re-flash the controller with factory settings and
actual cell data to have any kind of accuracy during
charge-discharge cycles. The software to do that (UBRT, for example)
is expensive (albeit it's available on per-battery license basis)

4) Usually the pack controller chip burns the controllable fuse on
the pack's control board when something is wrong with the battery to
prevent damage to the notebook. The restoration is possible, if
you're good with electronics and a soldering iron, but there is no
guarantee that the restored fuse will burn out the next time it's
needed and the batteries won't overheat trying to burn it. The right
way to do that is with Wood's alloy, which is much more toxic than
regular solder, which is "throughly wash hands after touching, don't
breath in vapors, only use in a well-ventilated area" toxic. Or you
can buy a thousand of new fuses from China. Did I mention that
different batteries, even of the same brand, have different fuses?

My own experience:
During my last trip to Russia I've used repacking services there
(Moscow):

Case (1): The pack for my Lenovo W700, the cost was 100 roubles more
than buying a new brand name, official, original battery, which I
also did.
The restored pack works well, in fact, I'm using it right now to
write this email, however, I had to re-do the controllable fuse
restoration myself because the soldering job was terrible and
dangerous, basically a huge drop of solder shorting the fuse and the
fuse cover is now missing. My rework is somewhat better, I'm not
very happy with it now, I did what I could, and was very satisfied
with it, only later realizing that it was only a partial success and
even that was more a matter of luck than skill in this case. I also
had to re-glue the pack's plastic case together, because the glue
job was ever worse than the soldering. But I have to thank him for
that, I guess, otherwise I would not discover the fuse.

Case (2): The pack for an old laptop that does not have a
replacement original battery available anymore. The work was done in
a establishment different from the first one. It works very nice,
just like new. Glued together well too, no idea what surprises are
inside though. I hope my field laptop won't blow up one day.

My advice would be buying a new original battery from a trusted
supplier unless it is not available anymore. In that case, I've
heard there is a lab in Netanya that does the "battery repair" (no
idea about the quality of the nature of the work). Or ask someone
who's going to Russia/Ukraine to repack a battery for you there (the

Re: OT: Where do I buy battery cells?

[vordoo]

  
  
Nice place, but "my" battery is not on
  there list :-(
  I think I need a more battery place then hobby with batters. 
  
  The search goes on...
  
  Thanks!
  
  On 2013-11-08 18:15, Marc Volovic wrote:


  Dealmetic.com is a possible arc. Check Rc section.


  


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Re: OT: Where do I buy battery cells?

[vordoo]

  
  
I know: "as buying from an amazon/ebay
  no-name looks risky with this kind of stuff."
  Can you recommend a seller?
  
  Thanks:-)
   
  On 2013-11-08 18:43, ik wrote:


  Ebay usually much cheaper then local stores in
Israel for many parts (but not all).
  
  

On Fri, Nov 8, 2013 at 5:00 PM, vordoo
  
  wrote:
  

  Hi,
  
  Where can I buy battery cells to rebuild a battery pack?
  
  Looking for Li-Ion spaciously LiMn2o4, 3.7 volt. For this
  time:-)
  Willing to pay a bit more in an IL store, but online store
  with IL or only U.S delivery is OK. 
  
  Appreciate any recommendations, as buying from an
  amazon/ebay now-name looks risky with this kind of stuff.
  
  Thank!
    
  


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Re: OT: Where do I buy battery cells?

[ik]

Ebay usually much cheaper then local stores in Israel for many parts (but
not all).


On Fri, Nov 8, 2013 at 5:00 PM, vordoo  wrote:

>  Hi,
>
> Where can I buy battery cells to rebuild a battery pack?
>
> Looking for Li-Ion spaciously LiMn2o4, 3.7 volt. For this time:-)
> Willing to pay a bit more in an IL store, but online store with IL or only
> U.S delivery is OK.
>
> Appreciate any recommendations, as buying from an amazon/ebay now-name
> looks risky with this kind of stuff.
>
> Thank!
>
>
>
> ___
> Linux-il mailing list
> Linux-il@cs.huji.ac.il
> http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
>
>
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OT: Where do I buy battery cells?

[vordoo]

  
  
Hi,

Where can I buy battery cells to rebuild a battery pack?

Looking for Li-Ion spaciously LiMn2o4, 3.7 volt. For this time:-)
Willing to pay a bit more in an IL store, but online store with IL
or only U.S delivery is OK. 

Appreciate any recommendations, as buying from an amazon/ebay
now-name looks risky with this kind of stuff.

Thank!
  

  


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