Anyone have the Lenovo ThinkPad S540?

You should ask it on the Lenovo Forum, people who own laptops in that model range or even that model laptop will answer your question.

http://forums.lenovo.com/...enovo.com/

ask under the 'Thinkpad' and 'ThinkPad Edge & S series'

i have a Lenovo z570, their pretty good quality, battery has on max power saving mode around 4 hours, and on normal mode around 1 hour 30 minutes (even after 2 years!)