Battery Low

Welcome to the rooftops of the organization's buildings. "The rescue" - a large organization for the supply of electricity.  This organization is often visited by alien drones. 

You are the protector of one of the stations. You have 5 defenders at your disposal. Collect batteries on the rooftops and deliver them to the station until it runs out of power. But don't forget that you need to protect the station from Drones.