I haven't put it through a rigorous test, but I can confirm that if I leave the laptop suspended without power, it will eventually lose its charge and shut off in what seems like a day. I only did this once by accident over a weekend; I've been using it every day and have the chance to charge it when I need to.

The only laptops I have ever owned that didn't have this problem after some fashion are Apple laptops, so I guess my expectations were fairly low on this topic.