I don't think there's a way to check.
About standby power consumption: with the lid closed (and power led turned off, and cpu scaling governor set to "ondemand", wifi/bt/usb off, idle cpu, clocked at 900MHz, OPP5), my unit uses about 22.75 mA. So with a 4200mAh battery (mine can currently store a bit more than that, because I'm using a relatively new one), that means about 185 hours of standby time. In the default setting (power led on, cpu scaling set to "performance", cpu clocked at 600MHz, OPP3), my unit uses about 29.17 mA, so that would be about 144 hours. I think the 200 hours claim is a bit of an exaggeration, but 100 hours is certainly an underestimate.