Uphill acceleration issues

[Amb3do]

I've got a 2010 Precedent that is slowing to almost a crawl going up hills. Using a GPS app on my phone I'm going anywhere from 12-15mph on a flat gravel road, but slow to about 6-7 mph uphill. I noticed that the pedal has to be almost half way down to the floor before I hear the motor click. I'm not sure if it has always been like that or if that might be related. I've only had the cart since April (bought it used).

So far I have replaced the speed sensor (because it was cheap and seemed worth ruling out). I have also tested the batteries the batteries with a voltmeter (>8 on all; 50.4 on the entire system).

Any advice or help is greatly appreciated. This is my first cart so I'm learning about them as I troubleshoot this.