Connecting a battery charger to the wall power and the scooter, bike, or go kart in the proper sequence will increase its lifespan. Here are some very simple instruction to help get the longest life possible out of your battery charger.
When charging the battery pack plug the charger into the vehicle first, and then plug it into the wall.
After the battery pack has been charged unplug the charger from the wall first, then unplug it from the vehicle.