Feed training by hand can be done, but the fish have to be fed at the same time every day, not even 15 minutes difference. The light will congregate the small fish in a certain area, and then when the feed in placed in the water, they will be there to eat.
A belt feeder doesn't need electric. It can be set to feed every 12 or 24 hrs, but you have to be on site every day to wind the spring.