[ltp] Running without a battery?

[Theodore Ts'o]

On Thu, Jan 15, 2004 at 08:30:04AM -0600, Ivarsson, Torbjorn (T) wrote:
> > The one thing which I'm not convinced about was the recommendation not
> > to use a battery while on AC mains, since the battery temperature
> > rises when fully charged.  I was fairly sure that on modern Thinkpads,
> > once the battery is fully charged, the charging circuit disengages,
> > and no power is applied to the battery until it has been discharged
> > below 95%.  Hence, it would seem that the battery should not be
> > getting hot once it is fully charged and the laptop is running on AC
> > mains.  Can anyone confirm this?
> 
> I got the impression from the article that the heat they referred to
> was the heat generated by the computer (CPU etc.) and not the
> charger. In other words (as I understood it), use only the battery
> when needed to avoid it being exposed to heat.

Um, sure, but the article talked about the inside of the battery
rising to 45 degrees centigrade (113 degrees Farenheigh).  If the
heat is being generated by the computer, then the heat would be
conducted through the either the battery case, or through the wires
leading to the contacts.  

Clearly the heat is not being conducted through the battery case, or
else the part of the battery case which is on the inside of the laptop
would be hot to the touch.  While it is possible that that much heat
might be transmitted through the battery contacts, one would think
that wires would melt first.

						- Ted