[ltp] X240: Sudden battery death

Jeffrey L. Taylor linux-thinkpad@linux-thinkpad.org
Tue, 8 Dec 2015 07:35:18 -0600

Quoting Jochen Spieker <ml@well-adjusted.de>:
> Jeffrey L. Taylor:
> > Quoting Jochen Spieker <ml@well-adjusted.de>:
> >> 
> >> I usually use the laptop on AC, but every or every other week I need to
> >> unplug it anyway and then try to discharge at least the external battery
> >> completely. Unfortunately, I cannot tell how many charging cycles it had
> >> because cycle_count returns 0 for some reason.
> >> 
> > 
> > Why are you discharging the external battery completely?  If it is NiCad
> > (Nickel Cadmium) this is resonable behavior (the memory effect).  If it's a
> > lithium battery, this will kill it quickly.
> "Completely" as in "down to 5%, then the internal battery takes over". I
> don't do a deep-discharge, of course.
> Mainly I want to avoid only ever charging from 80 to 95% and since I
> have bought extra warranty for the internal battery, I want to make use
> of that, too.
> As I said, I am aware that this is not the best way to treat a battery.
> But I am still surprised by it becoming almost useless in less than two
> weeks.

The advice I have seen is don't discharge to less then 20-30%, comparable to the
don't charge to more then 80-90%.  But it is also possible you received a
reconditioned instead of new battery.