About the Giant EnergyPak 500 Top Load Battery

Some batteries mount on a rack, others slide into the down tube or clip onto a frame cradle, and each mounting style depends on the bike’s design. Closest alternatives by price: Bosch PowerTube 500 Vertical Battery ($1,149), Brompton Electric Replacement Battery 36V 8.55Ah (Original) ($1,143) and Bosch PowerTube 500 Horizontal Battery (BBP3750) ($1,299).

Communication between the pack, display and motor often runs over a data connection, which is why batteries are usually tied to one particular drive system. People who keep a bike for many years will eventually need a new pack, even if the frame, motor and components remain in good shape.

Giant has 7 products listed, from $284 to $9,999.