From: "Yousuf Khan"

On 19/08/2011 2:45 PM, Paul wrote:
Yousuf Khan wrote:
Well, I ended up ordering a new battery online, and it came in today.
I put it in, and it's being successfully charged up. So my problem is
solved. Just wondering what caused the previous battery to fail in the
way that it did?

Yousuf Khan

I understand with the laptop battery technology, it isn't safe to
charge the battery, if the terminal voltage drops too low. The charger
won't touch it in that case. Now, why it's showing a little capacity
left, I don't know. Perhaps the undervoltage cutoff threshold value
has shifted ?

http://batteryuniversity.com/learn/a..._ion_batteries

"Over-discharging Lithium-ion

If the discharge continues to about 2.70V/cell or lower, the battery’s
protection circuit puts the battery into a sleep mode. This renders the
pack unserviceable and a recharge with most chargers is not possible."

"Copper shunts may have formed inside the cells that can lead to a partial
or total electrical short. If recharged, the cells might become unstable,
causing excessive heat or showing other anomalies. Li-ion packs that have
been under stress are more sensitive to mechanical abuse, such as
vibration, dropping and exposure to heat."

Sounds good enough to me, as a possible explanation.

Yousuf Khan

Good notebooks "regulate" the charge to the battery and I don't think the above is totally
the explanation.

I am glad thinks worked out for you. The lesson is for all intents and puprposes, what
you experienced is relatively normal as the batteries have a life. How they express their
EoL is not always the same.


--
Dave
Multi-AV Scanning Tool - http://multi-av.thespykiller.co.uk
http://www.pctipp.ch/downloads/dl/35905.asp