[ltp] X240: Sudden battery death

[Jeffrey L. Taylor]

Quoting Jochen Spieker <ml@well-adjusted.de>:
[snipped]
> What you can see is that the battery health appeared to be pretty stable
> over the last 12 months. But in less than two weeks, the remaining
> capacity ("last full" from /sys/class/power_supply/BAT1/energy_full)
> dropped from 94% to 18% in three steps!
> 
> 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.

Jeffrey