The first thing to consider when charging is - what type of electricity are you using? ; 110V? 220V? Most electric bikes will charge by plugging into a 110V outlet in the United States, and 220V in most European countries. To take electricity from the outlet and put it into your electric bike batteries, you'll need a charger. ; Sometimes this is integrated into the bike, and sometimes it is an external piece of equipment that you may conveniently leave at home or store in your pannier bags. http://www.summitcharger.com/electric-vehicles-charger/ebike-charger/