The boy was found was found with the serious injuries, including a fractured skull, in a car park in the Guildfords area, Harlow, with his e-bike also stolen on February 2.
More than a month on after the incident, police have charged three suspects in connection with the incident.
Lee Farrugia, of Spruce Hill in Harlow was arrested on February 10 and charged with robbery.
The 29-year-old was then further charged with dangerous driving, three counts of theft of a motor vehicle, burglary, driving without insurance and driving while disqualified.
He remains in custody and is next due to appear at Chelmsford Crown Court on April 10.
Police then arrested Jason Millard, of Oakdale Road in Forest Gate, last Tuesday (March 11).
The 36-year-old was charged with burglary and handling stolen goods, and appeared at Chelmsford Magistrates’ Court on Wednesday (March 12).
He has been remanded in custody until a hearing at Chelmsford Crown Court on April 9.
Charlie Farrugia, 23, of Spruce Hill, Harlow was arrested on March 12 and charged with robbery, theft of a motor vehicle and possession of a controlled drug of Class B, cannabis.
He appeared at Chelmsford Magistrates’ Court on Thursday (March 13) and has been remanded in custody until a hearing at Chelmsford Crown Court on April 10.
Essex Police continues to investigate and anyone with information is asked to call 101 quoting incident 348 of 2 February or visit the public portal.