[Thinkpad] TP600 Battery Pack problem

[Jonathan Graham]

> This is also an opportunity for "venting with flame"

In charging or in discharge?

In older lithium batteries you could get a runaway reaction during discharge
(ala the Japanese man who recieved facial injury from his cell phone).  In
lithium ion batteries this most significant danger is limited to the
charging cycle.  If you stick to using the charging circuit in the battery
pack.  There is no more danger of this happening than from charging your
battery normally.

Note that even if this kind of venting occurs this doesn't mean that the
Lion cell has ignited just that the vented gas/elctrolyte has.

>  Do you have a Class D fire extinguisher at hand?  Have you priced one
lately?

You're thinking of a 'real' lithium fire.   You don't need a metals
extinuisher, there is very little free lithium involved AND it's locked in
some other compound.  It would be highly unlikely to get the heat necessary
to release it.  If the vented cell ignites then you need to fight it with a
extinguisher that has a low temp and is electrially non-conductive.  Which
is why if you
check the MSDS for lithium ion batteries it says that CO2 is fine...and yes
I have a fully charged one sitting on my wall (I'd also recommend that if
something like this occurs that folks not only extinguish the flame but
properly ventilate the area).

> Seems to me like battery prices have dropped a lot recently.
> Maybe it would be more cost-effective to simply buy a new
> battery assembly than to replace the internal cells.

Depends on the time factor.  I'd like to see just how much time it takes me
to do the replacement.  Cells will likely be as cheap or cheaper than a new
battery.