so just so I am clear the 52v worked without issue?....thanks@SpiderDice It worked great. Gets a little hotter than the stock 48V and makes the original controller hotter as well, but it shouldn't be a problem. It seemed like it had more torque, even though I doubt more amps were flowing though the controller, but it definitely had more top speed in challenging situations. Overall I was very pleased. I am going to have to do some work before I can make the new controller work with the system.
@cbmojo No issues. The controller is rated for 60V and that battery maxes out at 58.8V with a full charge. I've used it maybe 5 times from completely full to completely empty with no adverse affects. I would say that maybe the controller and motor were slightly warmer, but I do ride pretty hard. It had more torque, top-speed, and less voltage drop than the stock battery.