My 650 rainbow X2 is like that now (haha, didn't start happening until the day after the warranty expired). I charge it fully (until the light goes out), stick it in a drawer, use it a couple of days later, and it's completely dead again. I only use it as a passthrough now, and even then, sometimes I have to wait a couple of minutes. This is with the good cable (thicker, better insulated, with gold connectors) that I now use on all my other out-of-warranty stuff (so much more dependable).
This is the same batt that has always run a little hotter and gave me all kinds of problems with the 5-click thing at first. I was OK with
those problems so I didn't return it, but I didn't know it would stop holding a charge too. Bummer.
One way to see if you have the same problem with yours is to charge it fully and let it sit for a couple of days, to see if it drains down on its own when not in use. Then I would email CS and get a new one before you get stuck with yours too.
