All Map Pilot variants use a user settable timer which acts as a target landing timer while using the battery's Smart RTH feature. The batteries keep track of how far away from the home point and how high the aircraft is currently. When it detects that it needs to head home it will do so. You can view this information in the Map Pilot debug panel. Any flight that is occurring down below 15% of the battery is considered unsafe and should be avoided.
Make sure your batteries are properly calibrated so you are able to get the most out of them.