Dell sucks!

Though others are not much better. :( Old Dell Latitude model suffers more.

The good news is newer machines seems to have better power management ... which is how I get to know the charger better.

Anyway, I've had 3 machines in last 4 years, the latest one seems to have longer battery life though it is Duo.

I have another laptop which I followed "discharged and charge" rule, runs great after 5 years of the same 2nd hand battery!