RAPTOR 2 | Most Powerful Direct Drive Electric Skateboard | Kickstarter

No… it all abouth timming of the pwm signal

The battery current is not a pwm signal.

sorry, but you’re looking at it wrong… the battery amperage draw is the one you multiply by the voltage to get the total system wattage. You cant go by the indicated motor amperage because it isnt constant. The duty cycle of the system means its amperage will always be higher.

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Nope not alwàys… look at vedder video… :wink:

not during regen of course… but as long as the motor is taking power and not making it… its higher.

“Electrical motors typically use less than a 100% duty cycle. For example, if a motor runs for one out of 100 seconds, or 1/100 of the time, then, its duty cycle is 1/100, or 1 percent. Pulse-width modulation (PWM) is used in a variety of electronic situations, such as power delivery and voltage regulation.”

Duty cycle… refer to the timming of the conversion the esc does from dc to ac

Dude you know what we mean. The important bit is that the battery current is the somewhat “constant” number and thus only this value can be used. The motor current without information about the used duty cycle at that moment is meaningless. Also you already noticed that energy can not be created out of thin air. The motors in this video showed a power of 1230W! Please @Ackmaniac back me up here. - you know these numbers better than anyone.

Also… do you calculate horsepower of a car from the amount of fuel needed or the power produce from the combustion

First batch will be 400 or 500. All orders should be in first batch.

That’s not a render. So ill take it as a compliment.

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All good things come to those who wait…

Doing some adjustments with our dyno. So will have footage from that soon.

& I’m just waiting for the new 10s4p battery to turn up at my house and my long, steep, hill climb video will be released.

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A better analogy would be: you don’t measure the power of combustion by measuring one cylinder and multiplying by the number of cylinders. Reason is that not all cylinders are “active” at the same time. The more reasonable measure would in fact be looking at how much fuel you burn per second (assuming a perfect conversion without losses). You will never be able to get more power out of your combustion than the rate at that you push fuel into the motor.

“The number of watts used by an electric motor at any moment equal the voltage supplied by a battery multiplied by the current flowing from the battery to the motor.” http://www.ebikeschool.com/myth-ebike-wattage/

Maybe double check your article because: “Watts can be used to measure the instantaneous power output (or input) of a machine, such as the electric motor on your ebike. The number of watts used by an electric motor at any moment equal the voltage supplied by a battery multiplied by the current flowing from the battery to the motor.”… witch in our case is 67amp (because the batt current is only a average of what is present on the motor and is not instantaneous)

33 volts X 36 amps is the wattage

Maybe there are two motors and the record being shown is just for one.

Motor amps are pwm as said so just on for a fraction of time and if they were to be averaged through the complete time period, including the off period of the pwm, it’ll be 36 amps.

FOC setup works fine, sensors detected

Sensor FOC working nicely

Plenty of power & only running 25A in each VESC at the moment because of the old space cell with 50A BMS

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How can a guy with an electronics background like you have so little knowledge about this subject and about how an ESC works? We are derailing this thread and I don’t want to continue this - there have been a number of people now telling you you are wrong and you still don’t want to believe them. Btw the voltage supplied to the motor is actually what is “adjusted” by the ESC - that means while you can use the 60amps you can’t use the full battery voltage. If you use battery voltage to calculate power you also need to use battery current.

ok then… tell me how esc work and I will be more than happy to admit that I’m wrong, and the research that I’ve made where misleading. :slight_smile:

But still… this tread is about the Raptor 2… And believe or not these motor can pull out enough power to make some geared setup jealous :smirk:

with the BSFC known, and the fuel consumption known, you can accurately estimate the power output. With an electric motor, we know the BSFC equivalent of efficiency for power out for power in. same for the controller… meaning we can estimate the output from the input, but more importantly we know the output will never exceed the input, and therefore know a max limit with 100% system efficiency… and thats all I was pointing out.

bad analogy… given that a flywheel is required to run a motor anyway… you literately are averaging the power of a full engine cycle(or multiple ones) to get the power measurement… you can just multiply as long as the engine is fairly symmetrical… If I am getting 80hp from 1cyl of my v8 @ 5000rpm, I can figure that as long as I have a similar layout, my engine is making 640hp.

just like if I am putting 3kw into a multiple electric motor system… if all the motors are identical in construction, load and power input… I can say that 3000/ number of motors is a valid 100% max… multiply it by the controller and motor efficentcy and subtract any constant loads like lights or the radio… and you can get closer… still not perfect, but close enough for what we’re doing.