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Inboard battery and braking: Fresh <> Full

You could pop your vesc heatsink through the enclosure and save yourself the hassle.

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oh by the way, to understand the OP’s confusion you need to first understand that coasting or braking will both generate power. the harder you brake the more power you generate. generally this power is soaked up by the caps and eventually charges back into the battery.
the point in question is that if the battery is fully charged what happens to the power?? some ESC’s will prevent braking from happening to eliminate the risk of over charging lipos and setting fire to your legs.
smarter designs will incorporate a BMS, which uses a series of resistors connected to each cell which will actually burn off (hahah bad choice of word) bleed off any excess voltage when compared to the other cells so that the cells always stay “balanced”.
One would then have to assume that a more sophisticated BMS would be able to also use a resistive circuit to bleed off any excess voltage gained by regenerative braking when the battery is hot of the charger full.

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Thanks @lowGuido. What are “caps”?

Are the registers used for balancing able to soak up a lot of current if the cells are all full?

So to permit braking in a “fresh” battery, Inboard is either undercharging, or using the BMS balancing registers, or using a dedicated braking resistor?

Is DC injection a viable method for braking e-skates?

caps = Capacitors
Also I am not speculating on the design that any particular people use in their BMS, either employing the balance resistors or a separate over voltage resistive circuit. either way, a resistor will work regardless of the level of charge in the battery.

they do not need to under charge anything.

This thread has been very informative. I realize now that i had no clue how regen brakes actually worked.

a cool thing to do is to hook up LED’s to your motor and then spin the motor to light the LEDs
doesn’t really achieve anything but its kinda fun.

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yeah my volt meter lights up pretty bright when i spin my wheels on my 6S.

That’s power son! Who knew?

so hold up i need to get the image in my head a little clearer… so regen braking is basically allowing a load to be put on the motors (which are now generators, or alternators?) by having the power it generates fight against the current that’s coming from the battery?

my artist brain wants images.

Yup. Generators. Maybe we could install plasma weapons on our boards to use up all of our downhill energy.

phased plasma pulse rifles in the 60 megawatt range, like the ones that the terminator was looking for in the pawn shop.

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Yup and we could shoot ankles and tiny dogs!

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the best way I can put it is like this:

if you dump a load of current into a motor and try to hold it still with your hand, the more current flows the harder it is to stop the motor from turning.

generator is motor exactly in reverse.

if you Suck a load of current from a generator and try to turn the generator by hand, its going to become very hard for you to continue turning the generator.

in closing, brakes suck.

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I think we could all settle this very easily with a beginner lesson.

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Good point. Let’s not forget we’re on longboards and it’s important to master the basic techniques too.

Something they forgot to mention in the video and something I know from first-hand experience: when footbraking avoid hitting your rear wheel with your foot or you’ll street your face.

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that’s also an excellent rule to follow when pushing. lol

A BLDC electric motor moves by running current through the windings to create electromagnets, timing it in such a way that the active ones will be attracted by the next permanent magnet, and repelled by the one it has just passed, moving the rotor and thus the load.

In braking, your movement/inertia is the power source that turns the rotor, pushing electrons through the windings by induction and thus supplying current to the electromagnets. The logic controlling the current strength and signal timing (charging the right phases/electromagnets) is reversed. Instead of facilitating this “hand-off” from one magnet to another, the process is rendered more difficult be repelling where previously attracted, etc. The battery becomes the load that you are “pushing.”

tldr: In forward movement, battery current pushes electrons through windings creating magnetic attraction/repulsion which turn the rotor and push you. Braking is your movement turning the rotor, using induction to push electrons through the windings towards the battery, creating magnetic friction that slows the rotor.


Thank you for a clear and concise explanation that my artist brain can handle. This makes perfect sense to me now.

Awesome! Here’s an even shorter version.

To braking, you push zillion electron. To moving, like in Soviet Russia, zillion electron push you.

(Could have made it shorter without the joke, but couldn’t resist.)

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The solution seems very simple to me if its possible. Just use DC injection braking and switch to regen when the battery is 95% full. and than switch again when the battery is 100% full.
does the VESC have DC injection braking, and Is it possible to do this switch thing with the VESC?