As far as battery life goes, e-bikes get their juice from a rechargeable battery usually located on or integrated into the frame, and many are removable, so you can power up wherever it’s convenient. The length of your ride and how often you use the bike will determine how frequently you have to charge up. “An e-bike battery can last anywhere from 15 to 60 miles depending on the terrain, how much assist you select, and the rider’s weight, among other factors,” says Jonathan Weinert, North American sales and marketing manager for Bosch eBike Systems. “With a dual battery [like the one Bosch has], you can double that range [around 20 to 120 miles], so it’s very feasible to commute for a week without charging.”
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.