GoKawiilInstead of wasting all the kinetic energy generated from braking like in traditional internal combustion engine cars, hybrids and EVs can capture all that potentially lost energy and convert it into electricity that powers its battery. Each EV maker has its own way of doing regenerative braking, but the general idea is that the electric motors that propel the EV forward can also act as a generator that captures the electricity generated from slowing down.
In cases where emergency braking isn't needed, regenerative braking will step in and create small bursts of battery charge and bumps in EV range. It's hard to say exactly how many more miles you'll get thanks to this, but the US Department of Energy said that regenerative braking results in 22 percent energy recovery for EVs in combined city and highway driving.