Author Topic: MX25V2 current limited  (Read 566 times)

Offline Leonsmits

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MX25V2 current limited
« on: February 14, 2024, 12:41:59 PM »
Dear Sir,

I have Fido 500W geared wheel conected to GM MX25V2 controller. Battery is 35 AH 48v with JK ballancer.

Motor is driving max speed about 50 km/h, so I limited to 55% in software (about 28 km/h now). Acceleration is set to 100% in software, but still have little torque. When speeding up scooter I can read in JK ballancer app motor is consuming 15Amps. When motor has reached max speed (28Km/h) motor is consuming about 7 amps.

It looks if controller current is limited to 15 amps, but in the software I set voltage to 48v and max current to 40 amps. Because my scooter has no peddels and I don't have PAS sensor, I left PAS in the software in the "high" mode.

Please advice to get more power.

Kind Regards Leon

Offline Bikemad

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Re: MX25V2 current limited
« Reply #1 on: February 14, 2024, 09:16:22 PM »
Hi Leon andto the forum.

Most BLDC motors will draw their maximum current at very low speed, and the current being drawn from the battery will automatically decrease as the motor rpm increases (and when the motor reaches its maximum governed rpm) which is why the current draw is so low at 28km/h.
However, if you were doing a constant 28km/h whilst going up an incline, I would expect the current draw to be higher than 7A.

Please note that a battery current draw of just 15A @ 48V = 720W, which is still 44% higher than the motor's 500W rating.

The Max Current settings available in the miroMAX version of the programming software is 30A Continuous and 70A Peak:



Unfortunately, I think this value is for "Phase Amps", which are typically much higher than "Battery Amps".

You could try setting the controller's "Motor Voltage" parameter to 24V instead of 48V to see if the torque increases.

Alan
 

Offline Leonsmits

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Re: MX25V2 current limited
« Reply #2 on: February 15, 2024, 05:47:32 PM »
Hi Alan,

Thank you for reply. I will try 24v setting.

But it seems that the acceleration curve is so defined that from standing still and accelerating it takes a while before 15Amps is consumed by motor ( the current is slowly building up). I would expect when starting with full trottle moter would consume 15 amps immediate and taking down the current when reaching max speed.

Kind regards leon

Offline Leonsmits

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Re: MX25V2 current limited
« Reply #3 on: February 16, 2024, 04:20:53 PM »
Hi Alan,

I tried and it worked, it makes a big difference in accelerating. Thank you for your advice, problem solved!!

Kind Regards leon :)

Offline Bikemad

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Re: MX25V2 current limited
« Reply #4 on: February 19, 2024, 12:59:57 AM »
Hi Leon,

Thanks for the update, it's good to know that the 24V setting has cured the problem.

Alan