It's not easy in today's freight to have rechargeable battery transported in wholesale quantities, I have a lot of issues on the freight company door, especially in China, They really don't understand what is safe and what is dangerous and ask a lot of things and costly paperwork even for a simple mouse NI-MH battery, This is more critical for air shipping, But even on sea shipping have some issues. This depends a lot of with shipping company you are using, some don't permit nothing, others do not care and are very permissive. It's a very stressful thing if you want to play in the right way.
Be ready to handle a lot of paperwork