I have a sterling diamond scooter. How can i use jump start to charge the battery? Is there any emergency portable charger to carry if i get stuck outside and there is no car or power.

If the batteries have been alowed to run down too far.when you plug the charger in the electronics in the charger will look for the 24 volts +/- 2 volt at the charging socket.if it dosent find this it will not supply a charging current to the Batteries.2 possable options here ,if batteries have not been left too long they may bump start,remove both batteries.either charge each battery individually with an old analogue 12volt 5 amp car battery for 1 hour each , then refit and try mobility charger or if a 12v smart charger avail and wont charge temp jump start charging with a good 12volt battery conected in parallel with the faulty one +to+.._to_ if both these methods fail the batteries have been damaged beyond repair and both will need replacing. keep new batts charged evrey time you use it and charge for min 10 hours. to avoid dammage and failure to replacement batteries

It might be easier to carry a spare battery. I am not familiar with your unit. I do not understand how a jump start would work without an external power source.