The teenager was injured on Saturday morning when he detonated a bomb he had made using gunpowder on a country path in Rhineland-Palatinate.
Due to the severity of his injuries, he was rushed by helicopter to a nearby emergency ward.
During a subsequent search of his house, police found more bombs and home-made explosives in the cellar.
Experts from the explosives unit decided to destroy the weaponry and ordered that all inhabitants within a 300-metre perimeter to evacuate.
While some neighbours stayed with relatives, around 250 were given shelter in an events hall on Saturday evening.
Police detonated the explosive materials in a nearby field and told residents they could return to their homes shortly after midnight.
At total of 150 personnel from the fire brigade, the Red Cross and other medical teams supported the operation.