If you disconnect the battery, it goes back to whatever BASE map you have loaded from the AP. If you are running a stock AP base map with other real time maps over it, then it will go back to the stock AP base map. If you are running a stage 1 93 octane map as your base, it will revert to that. Disconnecting the batter clears out the real-time map. To get to the absolute stock setting like straight from the factory, you have to un-install the AP, which has the effect of flashing your ECU back to the factory setting, like it was never modified at all.