That's what I did to my P910i's battery today. Instead of plugging in the charger during the afternoon, I let the power supply go on it's own. By about 10 PM, the redlight. This from a charge about 24 hours ago. I'll be leaving the phone on the Docking Station overnight, so we'll see if that affects the longevity of my phone's power supply. I've been told that draining the battery and then leaving it charging for prolonged times will improve the battery life. We'll see if that works. Or is it really just an urban legend?
Anyway, If this doesn't improve, I'm thinking of getting a new battery, perhaps a P900 battery, and try that out.
A day's power is fine- I have no problem with charging the phone nightly. But I'd rather it not be so stingy with energy... I bought the phone to use and enjoy the features, not to constantly worry about losing power because I want to watch a couple of videos or listen to some MP3s during the day.
Still, I have to feel lucky I guess... real PDAs don't last as long as cellphones do, from what I've read. Perhaps I am being too hard on my mobile.... Hmmm... Nah.