We are considering going to slightly higher voltage of 51.8V nominal instead of 48.1V nominal. I do not think this will hurt your controllers and motors, but I want to be sure. Is there a way for your controllers to only use about 48V all the time until the battery voltage drops below 48V? This would make the motors feel like steady power throughout most of the battery discharge instead of running very fast at first at 51V and then much slower at 45V when the battery is almost depleted.