Laptop battery life estimates outside of Apple are downright criminal. I'm still bitter over the time I bought a fully loaded Sony Vaio which had an advertised battery life of 11 hours. When in actuality, I only got less than three hours of battery life and complained, they explained to me that they meant it gets 11 hours of standby mode with the lid closed. I only made the mistake of buying a non-Apple laptop one more time with a fully loaded XPS which could barely manage 4 hours of battery life. I honestly have no idea how anyone can put up with non-Apple laptops. It's pure garbage out there.