Throttle control issues

I have a 2007 R&T 48v 6person cart. recently tried to drive it and the cart automatically goes as if in full throttle position(without touching the throttle) as soon as I switch the forward/reverse switch out of neutral. in addition, the brake stayed in locked position during this process. can anyone explain to me what part/parts are malfunctioning to cause this issue.
Also, I recently replaced the batteries w US batteries(std acid batts). I was told I needed to change the algorithm by one person(which I did),the employees at the battery store told me I needed to replace the IQ charger that was on board. can anyone shed some light on the correct answer?

Rough and Tough are a bit of an orphan. the fact that the cart goes puts you in the above average group.

Not having ever seen one I can only speculate that the throttle control needs to be taken apart and looked at.

If you have your Charger set to the right algorithm and it is functioning I can’t figure out why it should be replaced.

What brand is it?