A musicologist friend replied as follows, in case it helps.
---"
Never heard of him! If the quester has already looked at Grove, I'm
not sure I can come up with anything more without hard core research.
A quick Google search comes up with this:
http://www.answers.com/topic/ernest-charles (hardly much, but a tiny
tidbit)
seems to reference something called "All Music Guide" and a writer
named Lynn Vought. If he/she wants to see if finding Lynn Vought is
easier than finding out about Ernest Charles, I'm sure LV could point
him/her in the right direction.
Also there are some recordings available for purchase (amazon, cd
baby, etc). My suggestions would be - depending of course how much
this person REALLY wants the bio:
1) buy some of the recordings and see if the liner notes have anything
useful
2) go back to the college library and search in the RILM database for
"Ernest Charles" - if any recent articles have been written on the
guy, they should come up (recent being several decades, actually).
if he/she doesn't know how to access that database, a librarian should
be able to help
3) go talk to the reference librarian at the college music library and
see if he/she can help
4) try to track down Lynn Vought and ask for help
"---