Totally feel this. Battery life is such a letdown with some of these green gadgets. Had a similar thing happen last summer with a camping charger. The solar panel looked great, but the battery packed up by noon. Why do companies skip on the basics for flashy specs? Makes you wonder if they even test these things in real use.
Seriously, I ran into the same issue with a solar lantern last year. The box said it would last all night, but it gave out before midnight. What I learned is to always see how much charge the battery really holds, not just the fancy features. Companies often use cheap parts that can't handle real use, so they fail fast. Now I test new gear in my backyard before taking it camping. Saves a lot of hassle when you're not stuck in the dark.