User blog comment:B214/Question & Answers 5/@comment-97.103.233.248-20150414223519/@comment-26209278-20150414225155

So, during normal state, his power doubles every 10 seconds.

When in BB, the 10 second multiplier isn't applied, and he can double his power on demand. However, the more he doubles, the higher the stamina used, and the higher the host's capabilities required to maintain the power. Once he reaches the desired power level, he can then use that power to use for attacks. Too many boosts demands too much from the body, which is why he falls over in the RG vs Raiser (yes in normal state, but same rules apply)