I have the Phantom X model and read of someone upgrading to a 48volt battery (from a 36 volt) without changing the controller. Can anyone inform me if this is possible or if you have done this. I would like to get a little higher top speed but if this would fry the controller than maybe I won't. It is a 500 watt direct drive hub motor so that should be able to handle the increase voltage. Any feedback would be appreciated. Thanks