TSDZ2 Throttle + Temp Rollback Possibility?

Electric Motors and Controllers
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gomyles   10 mW

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TSDZ2 Throttle + Temp Rollback Possibility?

Post by gomyles » Feb 07 2020 8:31am

I'm making my own thread about this because it doesn't necessarily just apply to the Tongsheng Motor, but is relevant here.

Could you use the temperature sensor from the BMS, and have it wired directly to the motor, so that the BMS is actually measuring the heat of the motor and not the battery pack itself?

Keep in mind this would only work in low current applications where this is absolutely no concern about the battery pack overheating (Tongsheng TSDZ2 is a good candidate because they usually draw a max of 18A).

The Bluetooth Programmable BMS's (JDB among others) have a thermal programming feature where you can choose which temperature the BMS cuts the current flow leaving the battery ... so it could be programmed to a desired temperature.

Obviously a few measures would have to be put in place like extending the wires of the temp sensor and its added resistance, making sure that it is actually properly calibrated, and making sure that the BMS can effectively cut the current at the desired temperature level.

With that idea in mind the TSDZ2 could have throttle operation and temp rollback together.

And other motors that have built in controller's without thermal protection could benefit from it as well.


The idea could essentially work for any motor that you're able to glue a temperature probe onto to measure the heat inside the motor (again as long as the battery pack doesn't need the temp probe itself -> low current applications are what come to mind).


Just a thought? Would love to hear some feedback. Might be stupid but that's okay. Only 1 way to learn right!

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amberwolf   100 GW

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by amberwolf » Feb 07 2020 11:29pm

gomyles wrote:
Feb 07 2020 8:31am
Could you use the temperature sensor from the BMS, and have it wired directly to the motor, so that the BMS is actually measuring the heat of the motor and not the battery pack itself?
only by disassembling your battery, removing the temperature sensor from the battery, and then opening up your motor, installing the temperature sensor in the motor.

it would be simpler with less risk to just buy a separate temperature sensor of the right type for whatever the hardware you're using requires. (there are a number of types)


then you'd need to have an analog input on the controller that can read the temperature sensor, and firmware in the controller that performs the rollback function desired.

The Bluetooth Programmable BMS's (JDB among others) have a thermal programming feature where you can choose which temperature the BMS cuts the current flow leaving the battery ... so it could be programmed to a desired temperature.
unless the bms actually has a current-limiting smps (buck converter, at least), that is designed to handle the full current of the battery (which usually means it's rather large and has a fairly big heatsink to shed the heat generated in this process) it cannot limit current in the sense you're describing. I've never seen a bms built this way with this function.

if it's built with a typical bms fet output stage only, it would only be able to shut off the output completely, or leave it on completely, for any conditions it's setup for that trigger the state change.

gomyles   10 mW

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by gomyles » Feb 09 2020 2:33pm

Amber wolf,

Thank you for the detailed reply, I didn't realize that the BMS temperature functions served more like an on off switch.

I'll be building the battery so no need to disassemble.

I guess I'll have to explore if any BMS have the temp rollback functionality (perhaps just drop current to a specified value).

Thank you very much
Myles

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by amberwolf » Feb 10 2020 1:19am

gomyles wrote:
Feb 09 2020 2:33pm
I guess I'll have to explore if any BMS have the temp rollback functionality (perhaps just drop current to a specified value).
it's very unlikely, because they would have to have power conversion electronics equivalent to a controller, or charger, or buck converter, etc. (and be of similar size to one that also handles the same amount of power)


instead you would use an analog input on the controller itself to process the thermal sensor, and modify controller output as needed.


or use an mcu (arduino, etc) that takes the throttle signal and the thermal sensor signal as inputs, and sends a modified throttle signal out based on the inputs and your program's processing, to the controller.

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by gomyles » Feb 12 2020 6:18am

Thank you, really detailed and excellent response, really appreciate it!!

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by casainho » Feb 12 2020 4:46pm

Yes, would like to integrate the Smart Bluetooth BMS with our OpenSource firmware for TSDZ2 mid drive motor. It would be like this:
- the Bluetooth display SW102 running our OpenSource firmware already works with TSDZ2 running also our OpenSource firmware
- the SW102 would communicate with the BMS by Bluetooth and control the TSDZ2 motor, like disabling the motor on LVC or battery temperature. This same data about the battery could be shown on the display itself, like the voltage of each cell for instance or send the data to the mobile app
- TSDZ2 FAQ: issues and repairs, etc
- TSDZ2 OpenSource firmware

Developer of the Flexible OpenSource firmware for EBikes: TSDZ2 mid drive motor, KT motor controllers and displays: Bafang 850C color, SW102 Bluetooth and KT-LCD3.

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by gomyles » Apr 07 2020 4:30pm

Really appreciate both of your responses Casainho and Amberwolf


Another question :

Would it be possible to have some relatively low tech interface in between the battery and the controller that can power and monitor a temperature sensor and deliver output current based on the value of that sensor?

Something like an arduino powered (or similar) current limiting circuit, which would dial back battery delivery current (and therefore motor current?) in relatively easy fashion?

This is what happens when you just can't give up the throttle .... but really don't want to damage the motor .. trying to look for the solution to both here.

Would really appreciate your input, thank you!

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by casainho » Apr 07 2020 4:36pm

gomyles wrote:
Apr 07 2020 4:30pm
Really appreciate both of your responses Casainho and Amberwolf


Another question :

Would it be possible to have some relatively low tech interface in between the battery and the controller that can power and monitor a temperature sensor and deliver output current based on the value of that sensor?

Something like an arduino powered (or similar) current limiting circuit, which would dial back battery delivery current (and therefore motor current?) in relatively easy fashion?

This is what happens when you just can't give up the throttle .... but really don't want to damage the motor .. trying to look for the solution to both here.

Would really appreciate your input, thank you!
There is a project for TSDZ2 that does more or less some of that things

https://github.com/TSDZ2-ESP32/TSDZ2-ESP32-Wiki/wiki
- TSDZ2 FAQ: issues and repairs, etc
- TSDZ2 OpenSource firmware

Developer of the Flexible OpenSource firmware for EBikes: TSDZ2 mid drive motor, KT motor controllers and displays: Bafang 850C color, SW102 Bluetooth and KT-LCD3.

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

gomyles   10 mW

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by gomyles » Apr 09 2020 7:30am

Oh wow, that is exciting, thank you for that!

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Re: TSDZ2 Throttle + Temp Rollback Possibility?

Post by amberwolf » Apr 09 2020 4:03pm

casainho wrote:
Apr 07 2020 4:36pm
Would it be possible to have some relatively low tech interface in between the battery and the controller that can power and monitor a temperature sensor and deliver output current based on the value of that sensor?

Something like an arduino powered (or similar) current limiting circuit, which would dial back battery delivery current (and therefore motor current?) in relatively easy fashion?
as i said before (perhaps not explicitly enough), the *controller* is what does that.

you don't want ot add a whole other controller/converter in between your battery and existng controller, because that's what you'd have to do for the above, exactly as if you were trying to have the bms do it. so it would end up being as a complicated as a brushed controller, at minimum, plus at least passive electronics on the output to smooth the voltage on the output to let the existing controller operate normally. and heatsinks to get rid of the waste heat of the process. then, when current is being limited, voltage on the input of the original controller will drop, and if you limit current enough for whatever reason, it will drop so far the original controller will think it's battery is empty, and it will shut off.

so, anytime you want the battery current in a system to be limited, you need to have the original controller do it (or replace the original with something else that can), unless you want the complications, expense, and volume/weight of a whole second controller in the system.


so you would have to change something in the way the controller detects and/or limits current in order to do it. that is probably what the project casainho linked does--change the software in the controller so that you can change the limits (whcih i don't know if you can do in the original factory software).

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