another thing to remember the manufacturer of the Zappi panel reduced the current limit on these panels and they are slow going up ramps

OK SC3018 is a good model number, most likely cause switch on brake pedal out of adjustment (Brake adjustment will raise the pedal)

Pretty sure the model is an SC3018. It is a 1998 model. Not sure what the controller is but it is silver and about 2 foot long and mounts in between the battery and the counterbalance. It looks like a curtis controller with the 4 tabs for the power connections.

with the battery pretty much fully charged, but run around for 10 minutes [to remove what I call the "surface charge], what is the battery voltage, both at rest, (with no load on the electrical system), and under hydraulic stall for 3 seconds, (tilt back until the cylinder dead-ends, then hold the hydraulic tilt control handle back 3 more seconds). a difference of more than 10% indicates a battery that would cause the effect you describe. the battery does not have cohones to work the ramp any more...
the hydraulic stall test puts _much_ more load on the battery for this test than driving, even up a ramp.

Hello! what type of controller does it has?

Bit more info please model "SC30" is not an accurate model. what model and which scr drive system