Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

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mbgjt1   10 W

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Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by mbgjt1 » Jan 06 2021 4:48pm

Anyone have any experience with the QS205 50H V3 e-bike spoke hub motor? The 3T winding I am interested in is only rated for 408 phase amps.

Has anyone tried supplying more than this (500 phase amps) for very short periods of time (under 5 seconds)? Will the phase wires handle this current or do I have to upgrade them to larger ones with a thicker diameter for greater conductivity?

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by amberwolf » Jan 06 2021 7:34pm

mbgjt1 wrote:
Jan 06 2021 4:48pm
Anyone have any experience with the QS205 50H V3 e-bike spoke hub motor?
Some threads, there is more under other search settings. May not have info u are after.
search.php?keywords=QS205+50H&terms=all ... mit=Search

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by MadRhino » Jan 06 2021 8:55pm

‘’Only rated 408 Amps’’ what voltage? A QS 205 h50 does saturate around 32 kw. Feeding a motor close to saturation is playing dices. It could take it 10 sec, or only 1. I find 25 kw acceleration limit power is a reliable setting.

Anyway, If you find 400 A are not enough you should build a motorcycle and forget about hub motors. It won’t ride good if built on a bicycle frame, and the weight of motorcycle frames will be built much better with a motorcycle drivetrain mid drive.

The power that is not usable practically is... useless.
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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by mbgjt1 » Jan 07 2021 5:31am

MadRhino wrote:
Jan 06 2021 8:55pm
‘’Only rated 408 Amps’’ what voltage? A QS 205 h50 does saturate around 32 kw. Feeding a motor close to saturation is playing dices. It could take it 10 sec, or only 1. I find 25 kw acceleration limit power is a reliable setting.

Anyway, If you find 400 A are not enough you should build a motorcycle and forget about hub motors. It won’t ride good if built on a bicycle frame, and the weight of motorcycle frames will be built much better with a motorcycle drivetrain mid drive.

The power that is not usable practically is... useless.
Hi mate,

Voltage fully charged around 88V.

When you say 32kw and 25 kw power, are you referring to battery amps or phase amps.

For example, 25kw / 88v gives 284 amps.

Now is this 284 battery amps or phase amps?

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by MadRhino » Jan 07 2021 6:20am

I run from a 24s battery that can feed very high Amps but, I am talking watts. How many watts can be lost between those pulled from the battery and the actual power consumed by the motor is subjected to many factors, but none can be created. My settings are limiting the power from the battery side of course.
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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by amberwolf » Jan 07 2021 5:20pm

mbgjt1 wrote:
Jan 07 2021 5:31am
When you say 32kw and 25 kw power, are you referring to battery amps or phase amps.

For example, 25kw / 88v gives 284 amps.

Now is this 284 battery amps or phase amps?
Power is power, and is always watts = volts x amps from the same "side" of the system, so if you refer to a battery voltage then any amps you refer to must also be battery amps.

The watts themselves are basically the same on either side, except that the battery has to put out more total watts than you get to use at the motor-to-ground interface because nothing is 100% efficient, so there are heat (watt) losses within the battery, the BMS, the controller, and the motor.

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by mbgjt1 » Jan 08 2021 12:10am

MadRhino wrote:
Jan 07 2021 6:20am
I run from a 24s battery that can feed very high Amps but, I am talking watts. How many watts can be lost between those pulled from the battery and the actual power consumed by the motor is subjected to many factors, but none can be created. My settings are limiting the power from the battery side of course.
Hmm ok I think I understand. How is it that phase amps are usually higher than battery amps? For example, the 25kw power you are referring to comes to 284 battery amps if I am running at 88V.

But why are phase amps higher than battery amps. Is there a source I can read which defines each one, why can phase amps be much higher than battery amps. Does the controller multiply to add the amps per phase?

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by mbgjt1 » Jan 08 2021 12:11am

amberwolf wrote:
Jan 07 2021 5:20pm
mbgjt1 wrote:
Jan 07 2021 5:31am
When you say 32kw and 25 kw power, are you referring to battery amps or phase amps.

For example, 25kw / 88v gives 284 amps.

Now is this 284 battery amps or phase amps?
Power is power, and is always watts = volts x amps from the same "side" of the system, so if you refer to a battery voltage then any amps you refer to must also be battery amps.

The watts themselves are basically the same on either side, except that the battery has to put out more total watts than you get to use at the motor-to-ground interface because nothing is 100% efficient, so there are heat (watt) losses within the battery, the BMS, the controller, and the motor.
Would you be able to please explain battery amps and phase amps? Why is it that phase amps are usually higher than battery amps?

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by amberwolf » Jan 08 2021 12:28am

mbgjt1 wrote:
Jan 08 2021 12:11am
Would you be able to please explain battery amps and phase amps? Why is it that phase amps are usually higher than battery amps?
There's threads (some titled as such) that go into details, but it's because motor voltage is lower, and watts must stay the same.

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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by MadRhino » Jan 08 2021 4:01am

When you program the controller, you need to set a phase Amp limit. That is because when voltage supplied to the motor is low, the Amps can get much higher in order to feed the limit that had been set for battery current draw. High Amps are harder to travel through a wire than high volts, meaning that 100v 50A is running easier through the wiring than 50v 100 Amps, even if the 2 occurrences are travelling the same amount of watts at the end.

This may be difficult to visualize but, to make it easier let’s compare electricity traveling through a wire, with vehicles traveling on a road. The same total weight of vehicles can arrive at the end of the road each minute, wether this weight is from light cars traveling fast or heavy trucks traveling slow. Yet the road does suffer more from the passage of slow trucks than fast cars. :idea:
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Re: Siaecosys/QSMOTOR says QS205 3T limited to 408 phase amps!?

Post by E-HP » Jan 08 2021 10:07am

mbgjt1 wrote: Would you be able to please explain battery amps and phase amps? Why is it that phase amps are usually higher than battery amps?
If you are a visual learner, then maybe Goggle pulse width modulation and look at the Wikipedia article. The way I think about it, is phase amps are the maximum amps from the PWM output, but since the signal going to the motor is modulated, the phase amps are always changing (sine wave/square wave) and only at max for a couple of points in the cycle. The battery is providing the equivalent watts to supply the changing PWM signal/power going to the motor, but the current is lower since it is supplying the (average) watts to the controller that creates the PWM output to the motor.

The controller is supply 3 phases, 120 degrees apart, so the battery current doesn't swing like with the phase amp output, since the power of the three outputs will be equal to the power supplied by the battery, minus controller losses.

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