Target wattage from a motor?

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Blacksword   10 mW

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Target wattage from a motor?

Post by Blacksword » Jan 13 2021 12:54pm

Is there a rule of thumb for determining the largest wattage you could get from a motor before it starts to suffer ill effects example a motor rated at 6000w, how much could you reasonably push that 2x, 3x...?

Or is it pretty much a case of trying it until things break down. Has anyone tabulated different peak results for different manufacturers? I know performance calculators exist but I wanted to know what the real world upper limits of different motors have been.

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E-HP   1 MW

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Re: Target wattage from a motor?

Post by E-HP » Jan 13 2021 2:33pm

Blacksword wrote:
Jan 13 2021 12:54pm
Is there a rule of thumb for determining the largest wattage you could get from a motor before it starts to suffer ill effects example a motor rated at 6000w, how much could you reasonably push that 2x, 3x...?

Or is it pretty much a case of trying it until things break down. Has anyone tabulated different peak results for different manufacturers? I know performance calculators exist but I wanted to know what the real world upper limits of different motors have been.
Sure, plug in your motor and start playing with the parameters, and keep an eye on the time to overheating in the bottom section. If you're motor isn't listed (in the expanded list), the choose one that's similar to get an idea about how things behave.

https://ebikes.ca/tools/simulator.html

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spinningmagnets   100 GW

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Re: Target wattage from a motor?

Post by spinningmagnets » Jan 13 2021 3:00pm

It all depends on the loads you apply, and how much heat results. If you are heavy, and live at the top of a hill, you need a powerful system to avoid overheating.

If you live on flat land and are a light person, you can get adequate performance from an affordable and modest system.

Motors only draw the max amps on acceleration, so...how often and how hard do you accelerate?

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dogman dan   100 GW

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Re: Target wattage from a motor?

Post by dogman dan » Jan 14 2021 7:20am

Amen to that. The big thing we learned when I did all that motor testing for E bikekit.com was that the real killer of motors is overload.

Load it can take does increase as you jack up wattage, but for smaller 500w rated motors, about 3x the rated wattage was the most that makes any sense. Experiments with 6 and 8x the wattage was just determining how quick you could melt it. Yes, performance did increase greatly, especially when getting more watts from more volts, but it simply wasn't going to last very long running that much watts continuously.

It all just showed how wise it is, that typical kits from china run at most, 2000w through 500w motors. And the EBK versions run 1200w.

But if your motor is rated at 6000w, not the controllers wattage but the motor rating,, what the hell are you going to do with 18,000 watts.. I mean, this post is in the bike section, not the larger EV section. The 10,000 w bike I once rode was overkill enough. Took a lot of effort to keep the front wheel on the ground.

But on the other hand, increase load enough, you may need 18,000w. Like for example, you have a tadpole trike pulling a homemade camper.

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