[H-GEN] Li-Ion batteries.

[De Crow]

-----Original Message-----
From: general-bounces at lists.humbug.org.au
[mailto:general-bounces at lists.humbug.org.au] On Behalf Of Simon Ellis
Sent: Tuesday, 22 August 2006 11:26 AM
To: seqnug at seqnug.org.au; cbqmembers; general at lists.humbug.org.au
Subject: [H-GEN] Li-Ion batteries.

[ Humbug *General* list - semi-serious discussions about Humbug and     ]
[ Unix-related topics. Posts from non-subscribed addresses will vanish. ]

Hello everyone.

There has been a lot in the media recently about Li-Ion batteries getting
hot and catching fire or exploding. This is a very serious problem and Ray
Shaw has quite a good article about this in his Newsletter.

http://www.rayshaw.com.au/newslettercontent.aspx?NewsletterKey=31


Thank you.

Regards,

Simon Ellis.
 

Seems that there is a lot of info on this floating around, the following is
from another email that I received today.

Crowy
(aka Anthony)

FW:
Dell Notebooks explode - part two DANGER 


----------------------------------------------------------------------------
----


After several reports of self-combusting laptops see
http://www.consumeraffairs.com/news04/2006/08/dell_fire.html and
http://www.consumeraffairs.com/news04/2006/08/dell_batteries_history.html,
Dell is recalling more than 4.1 million lithium-ion batteries used in Dell
notebooks. The batteries were sold between April 2004 and July 18, 2006. See
https://www.dellbatteryprogram.com/Default.aspx for details.  Dell lists ten
different Latitude models, fifteen Inspiron models, four Precision models
and four XPS models. That makes 33 different models of notebooks that Dell
cannot guarantee will not burst into flames. 

Analysts ask why Dell? Did they use cheap batteries or was their notebook
design or manufacturing below standard?

Sony made the batteries so you can only surmise that they knew what they
were doing. Sony would undoubtedly be participating in the recall and
probably being hurt financially as well - batteries are not cheap (some
estimate the cost of batteries alone at USD 225M) and Sony has a reputation
to live up to as a reliable supplier. Frankly I don't think its Sony's
fault.

Was the design or manufacturing of the notebook below standard? A difficult
question, one that could land commentators in court, but if the heat
dissipation or charging circuitry was below standard then it could cause a
battery to ignite - and a lot have. It is reputed that Dell use a single
point CPU temperature sensitive, low cost fan - (does not measure battery or
case temperature), to reduce fan noise in their laptops but the trade off is
higher temperatures inside. With most notebook processors running at 70-80
degrees C (and sometime up to 100 degrees C - the boiling point of water)
that is a lot of heat to get rid of. Note that the temperature of a scalding
shower is around 60 degrees C and human skin burns/blisters at about 66
degrees C.

Dell is not alone however. Recently
 HP/Compaq have had recalls
http://bpr.hpordercenter.com/ebpr/landingpage.aspx
 Nikon had problems http://www.maxwell.com.au/service/notice/enel3.html 
 Apple had problems
https://depot.info.apple.com/batteryexchange/index.html?lang=en  
 There are many stories of people having issues with lithium batteries due
to faulty battery chargers
 Nokia had lots of problems when cheap counterfeit batteries flooded the
market.

So why is this happening now?

Lithium ion batteries (of any construction type) contain lithium which is
pretty volatile in certain circumstances. Heat it too much and it ignites
and produces a lot of heat and flame. Get it wet and stand back. Damage or
drop the casing and boom. Short circuit it and flash.

Lithium ion batteries use cobalt oxide, which has a tendency to undergo
"thermal runaway" - when you heat this material up, it can reach an onset
temperature that begins to self-heat and progresses into fire and explosion.
For example leaving a notebook in a locked car where temperatures can easily
reach 60-80 degrees C (with an outside temperature of only 30 degrees C) is
a perfect way to start a fire. 

If you rapidly discharge a Lithium ion battery it can also result in
overheating of the battery, rupture, and even explosion. Lithium-thionyl
chloride batteries are particularly capable of this type of discharge.
Consumer batteries usually incorporate over-current or thermal protection or
vents in order to prevent explosion. Because of these risks, shipping and
carriage of lithium batteries is restricted in some situations, particularly
transport by air. Now that lithium-ion powered laptops and MP3 players have
become favourite carry-ons transportation officials are re-evaluating the
safety risks posed on airliners and whether tighter restrictions are
required.

In 1999 a pallet of Lithium camera batteries caught fire on the ground at
Los Angeles International Airport after it was inadvertently dropped. The
FAA Tech Center undertook its examination of this more dangerous scenario.
They found:

* The original fire was caused by dropping only - physical damage
* A relatively small fire source was sufficient to start a lithium battery
fire.
* The heat from a single battery on fire was sufficient to ignite adjacent
batteries.
* The outer plastic coating on the batteries easily melted, fusing the
batteries together, adding to the intensity of the fire.
* The chain reaction ignition continued until all batteries were consumed.
* The molten lithium burned explosively, spraying white-hot lithium to a
radius of several feet as the batteries bounced around.
* The duration of the peak temperature increased with the number of
batteries, reaching as high as 1,400[degrees] F (as a matter of interest,
the melting temperature of aluminium is around 1,200[degrees] F).
* Halon fire-suppressing agent, injected in sufficient concentration to
"knock down" a fire, proved totally ineffective, even when injected after
just the first battery had caught fire. Nor did it have any effect on the
peak temperature. The fire continued as if Halon were not present.
* Lithium batteries catch fire with explosive force. When they burst, they
create a pressure pulse. The eight-battery test produced a pressure pulse of
1.8 psi, and the 16-battery test generated a 2.6 psi pulse.

Phew.

We are addicted to Lithium batteries because they don't have the memory
effect of traditional rechargeable batteries and pack a lot more power into
the smaller sizes. 

They are dangerous if not handled properly. But for the billions in use
there have only been less than 400 reported incidences of fire or explosion.
The percentages stack up.

I had the pleasure of seeing an affected Dell Inspiron in action. Over the
course of an hour of use the underside of the notebook became so hot that
you could not touch it. The owner had complained to Dell in the past,
especially as it was affecting the timber veneer top of his desk and was
told that heat was normal and if he was concerned to buy a notebook cooler
platform. On removal of the batttery there was definite heat discolouration
on the battery and in the notebook housing. In comparison my 2 year old ASUS
M6 notebook is more than comfortable to touch after an hour - the difference
perhaps between a "notebook" and a "laptop" - the later is fine for use on
your lap. See http://www.smh.com.au/articles/2002/11/22/1037697857595.html
for more on this definition.

Lithium Ion battery life facts - 

Most lithium-ion batteries have a discharge/recharge cycle life of between
300 and 500 times. In practice this is a life of about 2 to 3 years. Lithium
will last longer if its not fully discharged i.e. topping up is actually
better for their life and chargers are designed to stop charging when full.
Smaller batteries (like those in iPods or cameras) which are frequently
discharged/exhausted will not last as long.

Lithium batteries also have a shelf life - if left unused they will
deteriorate in 2 to 3 years.

Lithium batteries deteriorate far more quickly in hotter climates as well -
for example after 1 year at 25 degrees they will lose up to 20% of their
charge capacity, at 40 degrees up to 35% and at 60 degrees they will lose
40% after only three months. And this repeats for future years.

Lithium batteries should never be opened, put in water, or disposed in the
the domestic waste stream. Lithium bateries can usually be repacked by
specialist battery repackers.
_______________________________________________
General mailing list
General at lists.humbug.org.au
http://lists.humbug.org.au/cgi-bin/mailman/listinfo/general