Upgrading to 48v controller for Crystalyte 409

[dannytroy]

My hub motor is a Crystalyte 409, and I need advice on upgrading my 36v controller to a 48v unit, to match my 48v battery pack. I have a twist-grip throttle and am wondering if I will need a new throttle also. The present controller is rated at 36v/20A. I attached a photo of it. Any recommendations?