Probably, the battery stats counter, it has to be calibrated. You need to let the battery drain to 0% and then recharge it to 100%. That could reset the battery stats.
Also, If you have bootloader unlocked your N7 and installed ClockworkMod recovery, then when its discharged, plug the charger and boot into recovery and manually erase the battery stats data.
Also, look in the Play Store for some apps that can help you manage battery stats and other battery info. I must state that I am not a fan of battery saving / energy saver apps tough (they tend to interfere with the tablet operation as they turn off radios and other stuff...and eventually use more energy than the one they arguably save).