<P> The work out of the battery represents the amount of energy produced by the regenerative brakes . This can be represented by: </P> <Dl> <Dd> W o u t = η b a t t η g e n m v 2 2 (\ displaystyle W_ (out) = (\ frac (\ eta _ (batt) \ eta _ (gen) mv ^ (2)) (2))) </Dd> </Dl> <Dd> W o u t = η b a t t η g e n m v 2 2 (\ displaystyle W_ (out) = (\ frac (\ eta _ (batt) \ eta _ (gen) mv ^ (2)) (2))) </Dd> <P> In the case of internal combustion engines, the sketch of the DoE shows that average car efficiency amounts to less than 20% . We can see for ourselves that braking in proportion to the useful mechanic energy amounts to 6 / 13 i.e. 46% in towns, and 5 / 20 i.e. 25% on motorways . </P>

Regenerative braking is not found in which motor