what about the limitation for this in srilankan airlines ?
Don't know exactly.. Didn't fly UL for a long time as we don't want to miss the connections

Recently, I flew out from Katunayaka (two week ago) and the security guys asked me to show them the powerbank I had in my computer bag.
I believe it is now controlled by IATA regulations and the airport security in most countries do adopt similar conditions.
I noticed this first happened in China more than three years ago. They were checking powerbanks on internal flights. Checked baggage with powerbanks weren't loaded. Later on others started the same. I guess the Chinese suspected the batteries were responsible for MH 370.