I have the eGo type batteries(not VV) that came with the CE4 kit and the LED button is lit while charging. I thought that was odd at first. Now, I'm pretty sure these are knockoff batteries - no logo or anything on them, just plain. So while charging, the charger light is red(blinks green) and the battery LED is lit. When charge is complete, battery LED blinks and goes off and charger light goes solid green.
I also have a SmokTech Winder VV battery and the LED button is lit while charging also and charger light is red(blinks green). But when charge is complete the battery LED blinks and goes off but the charger light continues to blink red/green for some time. If I leave the battery on the charger the light eventually goes solid green.
Is this just the difference in batteries? I'm using the same charger for both batteries - the one that came with the eGo-CE4 kit (4.2v/420mA).