My stock VM Intercept 2.1 begins reporting the battery as 'charged' at around 65%, meaning that it will begin bleeping for you to remove it with popup messages. If you leave it on longer and either ignore the bleeping or put it in silent mode, the battery will continue to charge up to around 97% or so according to 3rd party battery monitoring apps. Sometimes this causes android to wig-out though, requiring a reboot to restore functionality. It seems best to remove it from the charger around 90% - 95%.
Also interesting is that it seems to take a long time for it to reach that last 20% ...don't know what's up with that. Compared to my G1 the Intercept takes forever to charge.
Maybe 2.2 for VM will fix it. lol!