XPS 13 9310, battery drain issue

A week back, I have brought XPS 13 and received it a couple of days back. I have never achieved the battery life suggested on the Dell website for the laptop. I agree it varies by usage and setting preferences. My expected battery life is between 5-6 hours after a full charge with zero screen brightness, no Bluetooth device connected, no Netflix streaming, battery set to balance, and power mode as best battery. I have seen some comments after driver and BIOS updates, it should be better but even that has not helped to improve battery life. It gives me great disappointment with your premium device. 

And once more small inconvenience faced by using the laptop while working in COMSOL. There is some graphic rendering problem and cannot see the output images. I have graphic rendering setting as my other Dell Latitude 5480 laptop which has core i3 7th gen processor.

I really love the performance and other features of the laptop and that is the reason for choosing it over other premium devices. Please provide a solution to overcome these.