Mechanism
Regenerative braking uses the hub motors as generators when slowing, converting kinetic energy into electrical energy returned to the battery. On Mellow Drive, regeneration complemented traditional riding technique — carving, foot braking where appropriate, and anticipatory slowing before stops — rather than replacing mechanical braking entirely on all gradients.
Recovery efficiency depends on speed, state of charge, and controller limits: a nearly full battery accepts less regen; steep descents may exceed what the pack can absorb safely, at which point controllers bleed energy as heat or reduce braking force — behaviours documented generically in EV systems of the era.
Rider technique
Riders who learned to modulate the remote and read terrain often exceeded flat-ground range estimates published for marketing. Conversely, stop-and-go traffic without regeneration opportunities and heavy Pro-mode acceleration shortened effective range. Mellow's riding guidance historically encouraged Eco mode for commuting and Pro for open segments — a split still relevant when interpreting 15 km ratings.