Evidence? The HP ProBook 6455b with 2.8 GHz dual-core Phenom II N620 and 6-cell battery has up to 3hr 50min battery life under normal usage (Internet surfing with wifi and 70% screen brightness), as shown in the following screenshots taken roughly 50 minutes apart:
|Before start writing this blog article||After writing this blog article|
While 3.8hr battery life isn't stellar, keep in mind that this is a 14.1 notebook with 35W TDP 2.8 GHz dual-core CPU and DirectX 11 capable GPU. I believe not many sub-$1000 Core 2 Duo or Core i3 laptops reach that battery life, and they usually have much lower-end GPUs.
(The notebook claims to have over 5hr battery life, which is the case when the CPU is idle at 1.0 GHz, the screen dimmed to the lowest and wifi turned off. I find such battery life number pointless, though.)