Hello Daniweb,
I've just purchased a new laptop, an Acer V3-571G which has an advertised battery of up to five hours. Obviously this is going to be dependant on what you are running, but even when using Ubuntu 13.04 to simply browse the internet, check emails and do some word processing, the battery discharges at a significant rate.
Attached is the discharge profile, which as you can see in about 50 minutes the battery is already 50% depleted, this being with the screen brightness reduced to the minimum and doing nothing which requires intensive power consumption.
Do you think it is a faulty battery, a problem with the laptop itself, or is Ubuntu 13.04 just very power hungry?