Some scooters are equipped with two charging sockets; one on the battery pack and another up on the steering tiller. The steering tiller charging socket is convenient since you don't have to reach down low to plug the charger in.
Occasionally, it will appear that the charging socket on the steering tiller is not working properly. For example, the battery charger, when plugged in there shows the battery as fully charged but then when you plug the battery charger into the socket on the battery pack, it shows that the battery is not fully charged and begins to charge the battery.
In these situations, it can be presumed that the tiller charging socket is not working. There can be two reasons for this:
1) The charging cord is not completely inserted into the socket.
2) The fuse that protects the battery from overcharging has blown. This fuse is usually inside the control console.
To test for a blown fuse, if you have a voltmeter, turn the scooter on and then put the voltmeter probes in the two opposite pin holes of the charging port. Your voltmeter should read 25 volts. If it doesn't, the fuse is likely blown.
If you don't have access to a voltmeter, you can visually inspect the fuse. To do this, you'll need to remove the screws holding the top and bottom halves of the console together.
SPECIAL NOTE: It is not possible to charge the battery when the scooter is turned on. Sometimes it can be confusing to remember to turn the scooter off. It's usually easier to always remove the key when charging the battery. This way, there can be no confusion as to whether the scooter is off or on.