Hughie Saunders, 20, from Stanford-le-Hope, Essex, was attacked at Cobham services in Surrey on 26 June and died two days later.
His mum said "[He] was the heart of the whole family. Our hearts are broken."
Mikey Coyle, 21, from Barnes, and Simon Baker, 22, of Outwood, have been charged with his murder.
Mr Saunders, who was known as Quhey, was "always laughing and lived life to the full", his mother said.
She added: "He had his whole life in front of him and was taken for no reason at all.
"The family is very close and he will be missed by his brothers and sisters."
Mr Saunders' mother thanked the staff who cared for him at St George's hospital, describing them as "angels".
She also revealed that he had donated his organs to save lives and wished all those who benefitted "a long and happy life".
Surrey Police is still keen to speak to every witness in the petrol station between 15:00 and 15:30 BST on 26 June. Anyone with any information is asked to come forward.
The family of a man who died after an attack at a petrol station on the M25 two weeks ago have paid tribute to their "kind-hearted boy".