Tricky diagnosing non start. If I may ask few questions.
1. Does the non start only happen for the same battery all the time or does it happen regardless of which battery?
2. It is possible your map was not downloaded correctly the initial time. you can always double check this after you have downloaded the map, turn off the wifi for the device so there is no internet than go to the area you preloaded and see if it displays. If it does the map is saved, if it does not, the map was not saved.
If it isn't able to save the map, there is a file permission problem and you may need to reinstall the app and pay close attention the prompts allowing permission for the app to access locations on your device. These locations are usually used to save items such as preloaded map. Inability to access these locations with the app because of permission issues would cause the non loading of map.
