Rheostatic brake

Hello all,

I have got a rheostatic brake for my electric skateboard project complimentary from the company I work with. I can’t find any information about it online, does anyone here know what is it good for and how to connect it (series to the battery or parallel)?

Hope to find some answers here.

That is my first post here so please don’t kill me if it is the wrong please the publisher my question…



heres a video - https://www.youtube.com/watch?v=RA4F01N1ZHY

might make sense just to copy the description under the video which is for 12S but looks like on the picture only for 10S:

Maytech MTBR1812 Rheostatic Brake

Battery: max. 12s

Operation voltage: 57V

Startup time: 200ms

Max current: 5A

Function: When regenerative voltage is higher than operation voltage, Rheostatic Brake starts working and reduces the reverse voltage to protect controllers. Size 70(L)*47(W)*19(H)mm Volt 50V Power Cable 20# AWG Length: 160mm Black and Red

If you start a trip from the top of a steep hill with a battery, the regenerative output voltage from the controller during high speed braking could exceed the maximum charging voltage of the battery, and under these circumstances, the battery’s BMS to disconnect the charging supply in order to prevent the regenerative braking from overcharging the battery.

When regenerative braking voltage exceeding the maximum charging voltage of the battery, BMS switches off, regenerative braking energy cannot be absorbed by the battery, then the controller of the regenerative braking voltage will continue to rise. After the regenerative braking voltage reached 57V, the electronic switch inside the Rheostatic Brake will start, the energy will be released through special braking resistor, so the braking voltage will be limited. The controller will be protected.

When regenerative braking voltage exceeds maximum charging voltage of the battery, BMS will disconnect.


I connect mine parallel with battery and have had no issue. This was recommended by the manufacturer.

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but did it also help you with something? could you run higher brake currents. if yes, how much compared to what you had before?

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Theoretically I can run higher brake currents but my brakes are plenty stiff as is


So you just have a box taking up space in your enclosure for no reason? :laughing:

Well, if you have space in your box for a box, why not? :tipping_hand_man:

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Are these rheostatic brake modules based on Ultracaps ? https://www.capcomp.de/en/ultracaps-consultancy-sales.html

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As b264 once said: the more parts you have, the higher the chance of something breaking.


I couldn’t help myself…

Nah, it’s just taking up space for testing and feedback :sweat_smile:

It’s not a critical component, so if it fails it doesn’t shut down the system like a switch. As the Battery pack grows in size and power it will be something needed in the future, it will protect your esc and battery from spikes in current, most escs can handle it but your direct discharge battery may not. Everything has limits


They do use 2 capacitors in the same principle as the ultra caps regen function but do not manage storage or current out like the ultra caps. the ultra caps can be used in principle, but cost-effective no. It’s more for solar, wind and water generated power storage and supply systems that cost $$$$


that little bit there that says 10s or below, we discovered that for them when they sent out the first batch. Circuit FW limits are not set to accommodate 12s, the 12s will be in production soon.


As for why?

A quad hub motor set up or any quad out/in runner will slam the battery pack with a heavy current with all braking at the same time, yes the escs will regulate this, but flawlessly? it’s a failsafe that if it fails your still safe, if it does its job your safer.

case in point: current battery build 12s6p with Sanyo 20700c 35a cells intended to drive 4 TB DD motors with 2 unitys.


It’s a good thing to have if it can withstand the excessive current, least time I saw this in motion it was a DIY solution from a Nordic guy who modded his pre built EUC. It would prevent brake cutting when battery was full, on top of protecting it from overvoltage AND overcurrent.

I’m waiting for the feedback, these things should have been around earlier.

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Just a pic.


Sorry to bring up this older thread, but have there been any developments on this? I’m really surprised these things aren’t in every board already, especially from bigger brands like Boosted seeing as this is a pretty large safety issue for those that live in hilly regions.

Can you literally just put one of these in parallel with your pack and be good to go?

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Yes. It’s that easy.

Here is why people don’t use them regularly. If you hit your throttle for 3 seconds, you’ve most likely used enough electricity to mitigate the situation. Unless you’re starting downhill from a steep hill at 100% battery, you will still have brakes. You will never regen more than you’ve used unless you’re solely downhilling and using regen brake.

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