math13 I was curious about "Students with more modern mobile were connecting easierly". Do you mean more than say 25 students were connected at the same time?
About the power requirements of the 3 B+, I have noticed that 3 B consumes less. I have a small (battery powered) USB power bank. Under similar conditions, about 15 connections, the 3 B+ LED starts blinking where as the 3 B is steady. I know, 3 B+ is also more powerful, which makes it less portable (for me).
P.S.. Sorry for walking in to a closed discussion!