I have not heard of a Triumph 4000 electric scooter before so I do not have any advice specifically geared towards it. However the first step I recommend taking is to do a Voltage check on the battery pack to make sure it is where it is supposed to be, and then, even if the Voltage level is good, performing a load test on the batteries to make sure the Voltage is not dropping too much under load.
Please let us know if you have any questions.
Robert Margetts
the scooter just bleeps all the time and will run sometimes ( well use to ) but now just bleeps any ideas ???