User blog comment:Mich, Michele & Kuhla/Future Units Preview/@comment-27268294-20160109022910/@comment-26336535-20160110015614

His SBB boosts his fill rate by 100% meaning each BC he collects counts as 2 BC. His ES reduces the size of the his BB gauge. So:

His maxed SBB has a cost of 66. 20% reduction makes that about 52. Then since BC is twice as effective, he requires 26 BC to fill his gauge, and then you might have some BC/turn buffers.