Can you add regenerative power to any EV ? YES u can

Most EV's , ebikes, escooters dont have regenerative or active energy production mode.

So there is a simple solution to add bonus to your actual system with low cost stuff electronics

U need some circuit that will pick up the energy from motor to battery while you touch brakes, plus a open / close reverse current from motor to battery circuit and a DC DC converter module to get up to batery voltage enabling charging.

Example for ebike:

-you have 2 brake switches that send signal to controller to turn off while braking, perfect.
-you will capture those 2 signals sum to control extra power ON/OFF MOSFET's relay circuit module.

-this circuit module enable/disable back current flow from motor to battery while any of the brake switches active (controller deactivates during this signals)

-To capture energy from brushless 3phase motor we need rectification.
-So we pick up some schottky diodes for high current, low voltage dropout. Parallel some and do a full wave rectifier or a voltage doubler rectifier, plus good rectification capacitors.
DC motor is direct out, so no rectification needed.

-This rectifier circuit is connected to motor cables phases paralleled with controller out phases

-Now back to enable/disable relay stage, this will be a simple MOSFETs module with control pin for enabling disabling current to battery flow similar to relay but electronics last forever.

-when any of brake switches ON , this module becomes active and motor energy will be rectified to DC and be sent out to DC DC converter module feeding battery, that DC DC module will convert voltage to 42V at limited current for battery charging CC

-After brakes non active , the MOSFET's relay module will become open circuit and current flows normal from controller to motor.

-Soon I can release some diagram of this stuff and bills of material electronics

Ive tested this system sucessful at escooter 2KW with 67,2V battery (voltage output from DC DC converter is adjustable to any battery)

-U can walk by feet pushing 2KW escoooter and charge battery 1Km walk gets 0,5Km bat capacity.
-At ebike U can pedal driving to charge battery , kind of capture energy extra mode while u keep pedaling

Assuming you have a DD hubmotor (or non-freewheeling middrive), you could just change out your non-regen controller for a simple cheap regen-capable controller.

Cheaper, simpler, and potentially more reliable.

Not that I'm against DIY :lol: , just that most DD hubmotor bikes *DO* already have regen capability, though the controller might not have it enabled.

And if not, the controllers that can do regen are cheap, probably a fair bit cheaper than all the parts you'd need to do this in a DIY way.


As far as charging while walking or riding goes, it's MUCH more efficient just to plain walk or pedal the same distance without it--you'll get there faster and much much less tired, and then just plug in to recharge.

The amount of energy you can generate using regen largely depends upon the mass of the moving vehicule.
Next, you need to consider that more and more E-bike motors use some kind of gearing to let the motor run at a high efficiency RPM.
Due to that, they also provide freewheeling so the motor doesn't has to rotate when it's not energised. This reduces wear out of the mechanical parts and makes it easier to peddle a bike with a dead battery.
So, on an E-bike, it only will work with DD hub motors. It might be interesting in an area with lots of hills to salvage some energy when going downhill instead of using it to heat your brakepads.
Your idea isn't all that bad as an aftermarket solution, so I am intersted to see what parts you will use, specially the step up and charging circuit.
On an electric car, regen should be implemented, or it's a really bad design. On an E-scooter, I am suprised they didn't implement it either. On an E-bike, you have considerations like weight and available space to mount additional electronics.

Most regenerative systems are only about 5% and ideal 10% efficiency

When you use regenerative dedicated circuit with voltage double rectification , plus high drain cap stage and than high efficiency DC DC converter, the efficiency can goes 30%

The regenerative force can be adjusted, when the regenerative circuit is at minimum impedance , the hub motor almost gets blocked sending out a lot of amperes of very useful energy! Once converted by DC DC converter, the amperage is safe for battery charge, using DC DC constant current supply to battery

Is possible to use this regenerative system for active energy production, for example you go downhill with ebike ,instead of braking U use regenerative motor back force braking while generating energy
Same active energy production system can charge battery when you pedal if you need some charge at your battery picked up from your physical effort.

Is possible to know the max back force produced by your motor.
-first step disconnect motor from controller, pick u 3 phase motor cables or 2 cables for DC motors. Short those motor cables with good connection. Try to move your electric veicule . If you have non invasive amperimeter check current amperes generated at one of the motor cables.

Isn't the idea that the battery and the motor helps you pedalling easier.
Pedalling to charge the battery will be the opposite of that. Downhill, agreed...

batteryGOLD said:

Most regenerative systems are only about 5% and ideal 10% efficiency

Click to expand...

Good ones are >80% efficiency. (i.e. controllers with regen)

The regenerative force can be adjusted, when the regenerative circuit is at minimum impedance , the hub motor almost gets blocked sending out a lot of amperes of very useful energy!

Click to expand...

Energy is amps times volts. At a low impedance voltage is close to zero - thus energy is close to zero. Ideally you match the effective impedance to the motor's VI curve to get the best efficiency. But in actual practice, people choose a single braking current that they like - something that helps slow them down, but not something so strong that it can cause problems. (Single current because most regen controllers have a single brake input. The Phaserunner is an exception here but there aren't many two-way throttles around, so it's hard to use it in that mode.)

Regen from downhill rolling has some (limited) merit, but...
Pedaling a DD hub Ebike ( or pushing a 2 kW scooter),..to regen the batteries is a totally pointless exercise.
Pedaling Even a 200W hub will kill the typical ebike rider very quickly ( 200w is about all an average rider can exert continuously !..unless your name is Merckx, Froome, LeMond etc ! )
Pushing a 2kw scooter to regen must be like a challenge for one of those Japanese game shows !
It is much easier and more energy efficient to free pedal and just push that dead scooter home.