Hi, this is a common problem with all most all electrical scooters the problems is going to be with the motor itself it has over heated due to the going up hill, i know they are made for this but after they get so hot they cut out and all their is left to do is get the motor replaced. their is no way of repairing the motor as they now build them as a sealed unit where as a few years back you could strip the motor down and replace any parts needed and get it up and running again but with today's throw away culture its just not done any more witch is a shame as their are many things that can be repaired if people took the time to look at them. As people or company's charge by the hour its quicker to replace than it is to strip it down if they did this you would end up paying more than the cost of a new motor due to the amount of time repairing the old one, so they don't bother they just replace them as a whole unit.

Now depending on how long you have had the scooter would depend on whether you have any warranty left on it this is always worth looking into as you could get the work paid for if you have any warranty left.
If the warranty has ran out then contact the place you brought it from and explain your problem tell them you was really happy with the product until it packed up and then see what kind of help they offer you.

If you bought it second hand then your only option would be to got to a scooter sale shop and ask them who carries out the repairs if you can do the work yourself then you could just order the parts from them but this isn't the kind of job somebody with no experience in this type of work should under take as its a matter of health and safety due to the fact that it is used around the public and cause cause serious harm if it ran into someone due to fault in fitting new motor and all the wires.

If your unsure what your doing then please leave this to a professional.

Let me know how you get on or if you need further assistance ok