Yeah, it shouldn't be that much different than a phone. So, if you aren't listening to music, either you have an issue, or you have a rogue app that is killing battery. Go to settings>battery, and look and see what it says is using battery. Being android, that can be inaccurate, and might need either resetting, and reinstalling apps 1 by 1 to check, or getting a specialized app that can track down what is chewing up the battery. On the other hand, maybe you just have a battery issue.
Has this happened over more than one occasion? Have you drained the digital battery at least once to get the system calibrated properly? Have you tried turning on airplane mode and observing what it is after that?