feasability of apower inverter to provide switchable regenrative braking battery char

feasability of power inverter for regen purpose on electric scooter

I have a new problem re: how to create an add-on regenerative braking circuit to an electric scooter that only has a one-quadrant power controller;
I was thinking that a few automotive relays-N.O/N.C. types- with some type
of D.C. chopper/oscillator circuit to step up the voltage from the electric motor the battery pack would work,preferably being switched from the brake switch.
I was also thinking of using a power inverter of around 150 watt continuous power that would work as the chopper section of this home built regenerative circuit.

I would like to know if anyone has attempted this using a power inverter
and/or how someone might step-down the voltage out of the power inverter to charge the scooter's battery pack???

I think you'd get so little extra power from the braking energy of the scooter that it wouldn't be worthwhile. Let's say you are riding around town and even if you brake every couple of blocks, the amount of time spent riding is much more than spent braking. Rather than thinking about trying to capture braking power, you might consider how to charge up some sort of auxiliary circuit that would store up and add to battery power as the scooter starts accelerating (especially useful when starting on uphill grades as electric scooters are not big on power).

Using a power inverter introduces too much loss, even if you were to use a 90% efficient one. The generated power over such a short time during braking would be very small and inconsequential in comparison to the initial peak current draw everytime the scooter starts rolling. It's like being penny wise and dollar foolish. You'll consume current at a much faster rate than the tiny amount you return to the battery. Perhaps a solar array that charges the battery, even when the scooter sits idle... provided you aren't riding it on overcast stormy days! Then you'll need to add a wind turbine to it for those types of days!! Your scooter will end up looking along the lines of that goofy "radio hat" shown in the ChitChat forum!

Re:reply to feasability of power inverter

The two replies indicate that this add-on power
inverter would not be worthwhile;as an alternative I am thinking about using the relays-as per the original post-to switch (via the brake switch)the motor termenals over to directly charge the battery pack and bypass the
motor controller entirely since it does not contain a regenerative braking circuit itself!

I would also like to wire the batteries in parrallel just for the regenerative braking part of the controll circuitry;the problem tthis would cause,I have no clue-is it possible to wire the regenerative bralking circuit in parallel
relative to the battery pack that is wired in series to give 24 volts WITHOUT producing smoke/short circuits??

that's what I was getting at-- even directly to the motor you won't offer it much benefit. Afterall, the wheels are decreasing in RPM, producing even less potential.

Hooking the motor directly to the battery will make the motor run at full power, exactly the opposite of braking.

"Free" Power

robo5050 said:

...the motor termenals over to directly charge the battery pack and bypass the
motor controller entirely since it does not contain a regenerative braking circuit itself!

Click to expand...

If the motor is a permanent magnet type, it will automatically generate output when slowing. Of course, any load you put on it will tend to provide braking action as well. You are right that you need to somehow sense that the motor is not receiving power from the battery at that time and connect the motor (with proper configuration of isolation diodes, you could recharge in parallel). If the motor requires both armature and field current, the problem becomes significantly more complicated but, none of that resolves the larger problem of simply not getting back very much energy which ultimately explains why scooters don't come with this feature.

I certainly wouldd not suggest that you give up your quest as it will be an excellent learning experience. Just don't expect that, even under the most ideal circumstances, it will give much advantage.