Understanding Maximum Brushless Motor Specifications
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- เผยแพร่เมื่อ 30 ก.ค. 2024
- When selecting a Brushless motor you will come across the different specifications provided by the manufacture of a particular motor. It is important to operate within these specifications. A brushless motors voltage specification is limited not necessarily by the voltage you can pass through the windings but the Max RPM. The maximum RPM limitation is due to a physical limitation of the rotor and the bearings of a motor. You can work backwards from the Max RPM and Kv value of the motor to determine the maximum applied voltage.
The maximum Current limitation of the motor is dictated by the resistance of the motors windings. A lower winding resistance will allow a greater amount of current to be drawn from the motor. A higher winding resistance will have the opposite effect.
Closely related to the maximum current rating is the maximum wattage rating. The maximum wattage rating is based on the motors physical size. A larger motor can dissipate more waste energy than a smaller motor. One thing to keep in mind is that a motor specified with a maximum output of 1000 watts, is not going to be able to achieve this with 1 volt applied. (extreme example) In order to produce 1000 watts from 1 volt, you would need 1000 amps. You cannot take the max wattage value and compute your own formula to determine the maximum current. There will be limitations on current whether they are specified or not. In many cases, it will be easiest to achieve the maximum wattage specification of the motor by operating relatively high in the maximum voltage speciation.
At the end of the day motor manufactures specifications are not the end all be all. If you require a reliable power system, do not ignore the temperature of your motor. Maintain the correct operating temperature of your motor regardless of the ratings in order to maximize reliability. - วิทยาศาสตร์และเทคโนโลยี
Love your videos man, thanks for your help on IG 👍
Glad I can help!
you are the best, please keep these great informative video
Thank you, I don't have any plans to stop!
If bldc motor rated as 72v 5000w continuously, I will get a 72v battery and the motor can go peak rated at 10kw. What is the maximum current can use and safety margin for current limit also?
Thank u sir very informative..
Most welcome
A 3 phase brushless motor has the following values. The maximum current drawn from the battery is 4.62 amps.. The thrust is 4025 grams with a three-bladed fan 18 * 8.. The speed at the maximum lifting force is 2780 rpm. The battery voltage is 23.46 volts. How much is the output power? How much is the efficiency?
I have a 36v 350w brushless motor connected to a controller rated for 36v and 15a. I checked the inside of the controller and the capacitors seem to be rated for max 50v. Now my question is what battery I can upgrade to. My stock battery is rated for 36v and it’s voltage range is between 30-42v. I don’t want to damage the motor or controller by installing a 48v battery (which generally charges above 50v), although I could replace the controller if necessary. Also this 350w motor is rated for up to 700rpm but no other specs are mentioned other than that it’s rated for 36v. The scooter in question is an evercross e1.
For your case. The best way is to get the same voltage battery with the voltage motor,.you mention that dont want to overheat your controller by getting 48v battery because its above the controller limit and below 36v battery will not full use on your motor. So to summaries: low battery voltage will not full use the motor, higher voltage might overheat the motor so the only choice is same voltage for motor and battery. What you can do is either upgrade all components or hold your 36v battery but get more Ah(amps/hours)
I have a 36v 350w connected to a controller rated for 36v and 15a. I checked the inside of the controller and the capacitors seem to be rated for max 50v. Now my question is what battery I can upgrade to. My stock battery is rated for 36v and it’s voltage range is between 30-42v. I don’t want to damage the motor or controller by installing a 48v battery (which generally charges above 50v), although I could replace the controller if necessary. Also this 350w motor is rated for up to 700rpm but no other specs are mentioned other than that it’s rated for 36v. The scooter in question is an evercross e1.
I fix escooters but am delving into this issue as so many people want to modify their scooters. Unless the scooter is faulty or you just want to experiment, you are better off selling the scooter and getting a better one. At this stage my opinion is don't over voltage the motor. With so many motors and controllers with same voltage, current and wattage specifications the ceiling height for each brand and model may vary considerably. For example, one controller may be running at or over it's desirable level thus may fail very quickly whilst others may be running well below it's maximum level to ensure reliability. One critical criteria used in electronics in Meantime Before Failure (MTBF), which means they test a design to see how long it lasts before it fails and, depending on the manufacturer what they wish the design to last for will determine the specified maximum voltage/current/power. But there are designers who aren't that clever and produce crap
Why ignore peak power? What is in-runner and out-runner? Isn't wire thickness relevant when we talk about resistance, thus current handling capabilities? Why does size matter for wattage? Is there a power or torque band on a Brushless motor?
Hey ryan, i have a mamba monster x 8s paired with a castle creations 2200kv motor, im using this setup with my arrma infraction for speed runs. Ive done my calcuations and the motor is rated for 60,000 rpm. 6s lipo max Running 2x3s lipo batteries in series gets me a total of the following
2x3s 5000 mah 50C 22.8 volts × 2,200 kv= 50,160 rpm
Running at 8s 5000 mah 50C 2x4s
29.6 volts × 2,200kv = 65,120 rpm
The motor is rated at 60,000, will going 5k rpm over damage the motor that much? Im running sensored and have it setup to shutoff around 160F°
Hey Colin, it's not that running the motor at 60,000RPM is ok and 60,001RPM will cause harm. It's at any point above 60,000RPM there is potential for the motor to fail. If your motor does fail by exceeding the maximum rotational speed, it's not going to be pretty. More than likely either the bearings will be an issue or the rotor will let go of the magnets. These types of mechanical failures would typically result in turning your motor in to an instant paper weight. More so, there is even a chance to take your ESC out in the process if you don't realize there is a problem and still pull the throttle.
RCexplained thanks for explaining. Appreciate it
@@colin1992 No worries
These videos are really great. If you replace the bearing in the motor you could potentially reduce the mechanical resistance of the motor and make it higher rpm to use higher voltage. I guess the balance of the rotor is also important as well.
Thanks Lawrence! Balance of the rotor is important as is its strength to handle additional RPM. The rotor can blow apart if over spun.
@@RCexplained I guess the larger the diameter of the rotor the more likely it is to come apart because the centrifugal force will be higher on the outside of the rotor.
@@LawrenceTimme yep, that's true!
Great Explanation Dude.. i have a query What happens if we use a 24V Bldc motor on a 18V supply.
Hello, thanks! Using a lower voltage than recommended for a motor will spin the motor at a slower speed. This will effectively decrease the power output potential of the motor.
So does the voltage or the current load determine the speed of the motor? As you mentioned the voltage locks the max RPM of the motor, which parameter is used to vary the RPM between 0 to max RPM? Love your vids!
Thank You for your comment Navin. Voltage determines max RPM. Your ESC uses PWM to control RPM in the range of 0 to max. This is a fancy way of saying the ESC turns the motor on and off several times per second to control the speed of the motor.
The motor is the load. Your second second sentence answers your first question
if Jim Carrey decided to explain BLDC's instead of pursuing an acting career.
Jokes aside, really helpful vid! Just subbed. I'm working with robotics and this explains so much that I needed to know about BLDC's that other videos did not mention! :)))
Thanks for the sub!
hi sir, i just have 2 questions for brushed and brushless
1. which of the two is better for aquariums?
2. can a brushless motor run 24/7?
Answered this in the other comment you left
I love the topic but im a visually learner. I love watching with some picture or animation
Hey English Barok TV, I am a visual learner too and can understand. I'm hoping I can bring more visuals to the channel in time. It really comes down to budget and time as I have no idea how to create accurate and detailed animations.
Can we use your videos to apply for ev conversion setup (specs)
Yes, all the same concepts will apply. You will just have to scale them to suit.
Could I increase the acceleration of my brushless motor by increasing the draw current?
You increase acceleration by increasing the torque at the wheels. This can be done in many different ways.
If the motor specification stated that max current is 63A. Does it mean that i Will get it constantly?
You need to look specifically for a specification stating something about the spec being continuous. Max to me would mean just that, just a maximum limited by time.
@@RCexplained but i didnt find continuous current in a spec description
It's probably best to ask the manufacture for the specification you are looking for.
@@RCexplained i have found 2 conditions for my power system. In the first condition i really max it out. Motor with I max 105A P max 2200W and R 0,00035 ohm. If i use 4000mAh with 30C (or 3,300mAh with 35C or 3,700mAh with 30c) and 125A ESC. Are those components Will be alright? Though im not using enough spare room?
@@RCexplained in my 2nd condition, ill use motor with Imax 63A, Pmax 1200W, R 0,0146. Battery capacity 2,700mAh with 30C and 100A ESC. What do you think sir?
If a motor is rated at 6s, I feed it 6s, but stay just below the max. amperage and only for short periods. Add that to an ESC that is rated anywhere between 30 - 50% higher than the motor will ever need, and this works a treat. Good performance, temperatures in check, and long life of all components. Going from zero to full power in an instant will ask a lot from the entire drivetrain, so I don't do that often. Just my 2 cents guys. But obviously, if you are a hard core racer, you may forget all of the above and go like hell!
Right on Remko. That's a great explanation to keep a power system reliable!
Hi Ryan, I really like how you explain this motor stuff, can I contact you via email as am working on a project I would like to get some advice on.
Yes, visit the about page.
Hello! I was just wondering maybe you could make servo videos and radio videos too? thank you big fan
Thanks for the comment James! Do you have specific video topics in mind about radios or servos?
@@RCexplained not sure if it will interest most people. But i really dont know what the big deal is with digital servos, brushless servos, coreless. Glitching issues and how to avoid them maybe?
Thanks James. I can place these topics in queue. In addition, check out the digital vs analog videos:
th-cam.com/video/2TVmWbIM3IM/w-d-xo.html
th-cam.com/video/tYkLsn10Eu0/w-d-xo.html
@@RCexplained alright. More power!
HI THERE, GREAT VIDEO, THANKS. SINCE I BOUGHT MY NEW ELECTRIC WHEEL CHAIR, I HAVE NOW OWNED THREE BRUSHLESS MOTORS. 500 WATTS, 1,800 WATTS, AND NOW 2,000 WATTS AND SOON A SECOND 2,000 WATT MOTOR ON THE BACK AXEL. ARE ALL BUSHLESS MOTORS MADE IN CHINA LIKE THE THREE I HAVE? CAN I BUY AN AMERICAN MADE MOTOR?
You can get American made motors.
Do you know why a manufacturer would only rate a motor for 3s max voltage when it says its max rpm is 100000?
Yes, the answer to this question will be in the video released today.
Cool, thanks.
Please explain this to Hobbywing. According to them this specs doesn't exist in the RC world.