The small black item with the red button is a circuit breaker. There is a number on the end of the button, that is the amperage rating. When the button pops out, it's tripped. To reset, push back in till a click is heard. The other item I'm not sure of, it looks to be wired between the motor and the ESC. As for a battery, is there a Batteries Plus or an Interstate Batteries near you. They should have a sealed lead acid battery, gel cell that would work and the correct charger. A gel cell needs to be charged with a low current almost a trickle charge. Home Depot or Lowes might also have one in the electrical department with the emergency exit lights. I have a number of old emergency exit light chargers that make wonderfull cheap chargers.