[Tfug] Li-on battery

[John Karns]

I recently bought a new battery to replace the aging one on my T42p
Thinkpad.  Got it on eBay for a lot less than what others of the same
capacity are going for.  After charging it, it seemed to work as
expected in terms of runtime.  Then I noticed that after leaving it
lugged in for extended time periods, that the charging indicator light
would start blinking amber, indicating that it was not charging.
Waking the machine from sleep mode and shutting down seemed to jolt it
back into accepting a charge.

But the estimated remaining available time didn't seem to accurately
reflect what I estimated to be the remaining time, so I decided to
deep-cycle it once to see if it would correct the problem, after doing
some searching around the 'net, and reading some forums.  I ran the
machine until it died, doing memtest86.  Since then, about 3 days ago,
it won't charge - the charge light always blinks amber - so that's
likely the 1st and last time I'll ever deliberately deep-cycle a Lion
battery.  (How I loath Li-on batteries!  How I wish I could choose a
NiMH battery - they just seem to be a lot more forgiving, and not to
age a lot more gracefully!)

Now I've read some messages where people advocate putting a
non-charging battery in the freezer overnight, then connecting it, as
a last-ditch effort to jolt the battery chemistry into accepting a
charge.  And of course there are others out there who take the
opposite POV and urge that it should absolutely never be attempted.
But I question whether some of these people have anything approaching
comprehension of the factors involved.  E.g., one warns that the Li-on
batteries freeze at 32 deg F (same as water), and that it's probable
that the one or more cells will rupture, causing a fire (also saying
that mere exposure to air will ignite a ruptured battery).  I
certainly don't want to see my laptop go up in flames, but neither do
I want to throw away another $50 on a battery, w/o at least trying to
salvage the one I have.

Anyone have any input on the subject?

-- 
John