We have a business where we are getting large amounts of 1 and 2 Baht coins. The local banks don't want to take them, businesses don't want them, and customers do not want them as change.
Any suggestions on when to exchange them? We package them in clear bags in 100 baht increments.
The bank must accept them!
I think they will charge you some small fee because the job of counting them.
Try to check with neighbour businesses around you, many will be happy to exchange because they need small money.
I myself exchange money notes to coins once a year when I run out of coins!!
The 2 Baht coin is a pain in the axx. I always keep them separate from the 1 Baht coins!
*7-11 is also a place you can use coins no problem.