Pressing the brake pedal only slows the vehicle, B5 regen uses the electric motors as generators which then charge the battery. The braking actually will reduce the effectiveness of the regeneration charge.
The 12kw battery would cost 12*0.16 = $1.92 however because of efficiency, as it takes 5 hours at 15amps (5*(15*230))) =17kw was used which = 17*0.16 = $2.76 to fully charge from empty.
Regards Johnv
