bafang pmgr 24 v at 75v reliable?

hello , i read in the forum that you can run the bafang motor pmgr at 72 v !! Is it reliable?

Actually i ve a bafang pmgr ( http://www.szbaf.com/product.asp?id=6 ) or originaly 30v/ 15 A i run it at 50 V (12s lipo)/15A. The controleur is an ecrazyman 48v/15A 6 fets controleur. I program it with xpd to have exactly 15A at max trottle. Original programation of ecrazyman controler send 20A so 1000W to the motor, i make some run at 1000W and the motor still alive!

It s ok it run since 6 month with no problem! top speed 45 km/h (28 m/h) and max power at full trottle : 750W.

I buy an 72v/45A ecrazyman controleur an i ll try it on the bafang with 18s lipo (75v max ) and program max current 15 A do you try this configuration? it say in the forum max voltage 72v/ 30 a!

is it reliable? i think i ll keep the trottle to have only max power to 750 w?


thnks for the info

if its direct drive, you could do it, i did it to my golden motor and i ran it at 100 amp peak to.
but
reliable, no way, my golden motor did not burn but the hall sensors certainly did,

if that bafang is geared, i would not even attempt to overvolt it.

if you want something with good speed, save up some more money, make the whole setup reliable, unless this is for your wife or gf who just wants to ride with you now and then..

Kurt,member here, runs his on 15s in a 20" wheel with 0 issues.

I'll be running mine on 18s here in a few weeks, but 45ampa is too much. Try 25... Since higher voltage will make up for it.

72v/30a would burn up my motors that are twice as large, such as my MAC geared motor and MXUS DD hub.

I'd say this would be a great learning experience for ya :lol:

I'm trying 18s lipo on the Bafang BPM motor in a couple of weeks.
Only the smaller rated 250w motor I think your pushing it with 1000w running through it. Or at least you manage to put a decent amout of pedal power into it or there are not that many hills where you are.

With 72v 15amp max thats still a good 1100w+ going through it. You maybe ok as the amp's are low. But the additional speed means the motor will try pulling those sort of peaks more often. Meaning you are pullling 1100w+ for a longer time. Longer time at those watt's means more heat build up and as such means burnt up motors.

The newer Bafangs seem to come with much stronger gears than the last set. But please note the higher speed means the nylon / composite gears also create friction heat. Thats before the clutch starts to become unreliable.

You can try it and maybe as long as you do bursts of power and treat it with some care you maybe fine.
I'm still worried about running it on the much larger BPM but again with have to excercise some caution to my throttle use. I also feel if I was just to keep it on continuously and ride it would eventually fail from heat.

Try it. These motors only cost about $80 USD anyway

It depends on your definition of reliable. Will it work? Sure. Will it fail? Guaranteed. The question only question is how long it will last. Keeping the current low and a small tire certainly help with the stress put on those gears, but the higher rpm will definitely wear them out quicker. My view is jaded, because I wouldn't use the word "reliable" without the "un" prefix in any sentence about plastic geared motors, because you're always just one wrong tire slip away from peanut buttered gears.

My attitude is why even bother with the weight savings of a geared hubbie. Saving a few pounds only really matters if your tire is leaving the ground, and if it is then the shock loads on the gears upon landing is sure to cause a premature death.

Exactly. It all hinges on what you call continuous use. If your ride is nice and short, it would be reliable. If it's a nice long ride up 10% grade, it would not. If you weigh 120 pounds it might be reliable, if you weigh 220 it might not.

Chances are, you better have a short ride in mind.

hello

actualy i use this 24v/250 W bafang reducted motor at 50v and 15 A max. I use it since 6 month 2/3 hours by week never had a problem.
more info here http://cyclurba.fr/velo/589/48-v-moteur-et-velo.html (i m french ).

in my run i pedal all the times and i m very moderate on the trotttle , generally max watt under 500. at max trottle on flat the speed is 28 m/h and the amp to the motor are 7-8 A
in hill climb i dont push the trottle to 750w, but i m trying to keep max power under 500w.
i plan to use it in the same condition.
i read here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&start=0#p72825 that this user use it at 72v 30 A!!

so thats why i want to try!! i think thats more volt with the same power and i ll have more top speed on flat, perhaps better hill climbing facilites (500 w max on hill)

thanks

John in CR said:

My attitude is why even bother with the weight savings of a geared hubbie. Saving a few pounds only really matters if your tire is leaving the ground, and if it is then the shock loads on the gears upon landing is sure to cause a premature death.

Click to expand...

I don't think many people choose a geared hub for the fact its lighter. Its more to do with the gear reduction, improving effciency and torque to boot. But you'll find alot of people choose them due to the free wheeling ability over most things.
As you say weight is not that much more of a priority.

Still these motors are rated at 250w and 3 times that is probably there peak. The fact your running 1000w through them currently is probably pushing them. At 72v same amp's its really gonig to be testing the small motor.

Not saying don't - but just be careful with your use. At that power its well and truly past its limits.

kergoat29 said:

hello , i read in the forum that you can run the bafang motor pmgr at 72 v !! Is it reliable?

Actually i ve a bafang pmgr ( http://www.szbaf.com/product.asp?id=6 ) or originaly 30v/ 15 A i run it at 50 V (12s lipo)/15A. The controleur is an ecrazyman 48v/15A 6 fets controleur. I program it with xpd to have exactly 15A at max trottle. Original programation of ecrazyman controler send 20A so 1000W to the motor, i make some run at 1000W and the motor still alive!

It s ok it run since 6 month with no problem! top speed 45 km/h (28 m/h) and max power at full trottle : 750W.

I buy an 72v/45A ecrazyman controleur an i ll try it on the bafang with 18s lipo (75v max ) and program max current 15 A do you try this configuration? it say in the forum max voltage 72v/ 30 a!

is it reliable? i think i ll keep the trottle to have only max power to 750 w?


thnks for the info

Click to expand...

Run conservatively the Bafangs are dependable little motors. I used my first slower-wound Bafang for 5,000 miles at 750-1000W and the gears still looked perfect. I used it sensorless another 1,000+ miles until switching to another motor.

I was however able to damage a 250W Bafang "24V" version like yours on 51.2V/20A. All it took was a warm summer day, a fast long ride, and a couple of good hills at the 25 mile mark to do it. The motor got so hot the hall wiring melted and fused, still the gears and windings sustained no damage.

I replaced the motor core with another "24V" Bafang and presently run it on 12S LiPo for a 29mph top speed with a 700Cx40mm tire. It is fun getting so much speed from a 6 pound motor but the fact is pushing the 250W Bafangs this far is already risky. If you're a lightweight rider who does short trips over flat terrrain you may have no immediate problems going with 75V but it's certainly not a combination that will be reliable over the long term. Besides if you're after a significantly higher top speed you're not going to get there by limiting (battery) power to 1000W, which is good for about 30mph (48 kph).

No, if you want more speed and power go with a bigger motor...or dual high-speed Bafangs!

-R

So the answer is yes. But dont keep the throttle pinned down constantly.
I only run the bpm at watts of 1000w peak and a top speed. The motor barely gets warm with my commute and that's with WOT 90% of the time. Hence why I'm going to try it at 72v for hopefully 30ish mph. But I think the heat it will make on 20amp I'll have to watch. Even then I'm probably pushing it.

Do it and let us all know how you get on.

I'm getting mine next week, and I'll do tests on 48,60, and finally 72v.

The tq from geared motor owns a dd motor anyday, and freewheeling. Why not keep 12s lipo and bump up the amps a hair to have more tq. On a full rigid mtb(like mine) 30-32mph should be fun!

I'm glad those with real experience were willing to chip in here.
I don't have experience with the smaller bafangs, but i do with small geared hub motors like the MXUS and some other off brand which was probably a cute or bafang in disguise.

Both would get warm at 500w constant use. I could not imagine doubling the power to 1000w with the hills i have nearby. That would mean dead motor with no replacement gears available.

That's why i like the MAC and BMC motors. Never heard of anyone cooking the windings before. The replaceable clutch, keyway, and gears will go first.

Again it just depends on how much you punish it continuous. I've melted a fusin motor similar to the muxus or bafang in less than
4 miles of ride. But it was 112 F, and the ride was 3 miles up 7% grade, 48v 15 amps. Might have survived if I climbed it with pedaling, but I was destruct testing motors, and the little gearmotor failed. All the dd motors the same day made it fine.

Point of the story is, you try hard enough, you betcha you can flame that motor. And the flip side too, you carefull enough, you bectcha you can ride it without melting it. All up to you my freind, and how you ride.

That's why i rate my overall power level going off of how much of a hill it can take continuously.
Why ride the edge of the spec on any component.

Design it for the worst case scenario, with a thermal buffer and it will never die on you.
If you can't handle that, head straight to high power motors like DD hubs in tiny wheels on high volts, Crystalyte X5, etc and stop trying to see how fast you can blow a tiny geared hub running 5-10 times the power it's designed for.