Golden Motor

[SEVCONONE]

I see some of you use Golden Motor products including their 5kw BLDC motor.
Whereas i am sure their Magpie controllers etc are fine I must warn all of my experience with the bigger 10kw version of the brushless air gap motors
My use is for a quadricycle so needed 10kw to get up to 40mph against 30mph with the 5kw version The 5000 model I now have surplus to requirements if anyone needs one for a motorbike.
The 10kw version is a copy of the Motenergy (Mars) ME 2012 and Motenery I believe are to pursue Golden Motor in the courts for breach of copy-right They hold the patent for the air gap disc type of brushless 3 ph DC motor.
I have had 2 0f these motors with failed permanent magnets and Golden motor are refusing to answer my email as the motor is only a few months old and I need a refund.
They do not have a written warranty so when the first one failed I had to pay a lot of delivery charge to have another one sent which took about 3 months. Now the second one have gone down no reply at all after many emails. I had already purchased a third one as I wanted water cooling so have swapped for now I had also sent for the water cooling end cover for the second motor and it ran with cooling for about 50 miles before packing up These motors have cost a fortune and I do not no how long before this one fails. They get extremely hot as there is no ventilation (sealed motor casing). and the heat does not disperse very well to the water housing that replaces the useless fan fitted to the air cooled version. There is a deep flaw in the design I think they only copied the winding's etc inside the motor and do not fully understand the the emf produced etc so the magnets lose their magnetism causing the motor to lose power dramatically. The original one they blamed on poor quality rare earth magnets but I do not think this is the only problem.
I gave them permission to put a video of my buggy on the Golden Motor website, its under the car conversion section as all they had was a 10kw motor strapped to a VW beetle and a pathetic cart video. that traveled at about 5mph. I have asked them to remove the video several times but it is still there. I do not want my buggy accosiated with their crap motor as I am using a ME2012 motor now just need to get it set up with the Sevcon controller
Hope anyone using the 5kw Golden Motor has better luck Colin R

 

[nechaus]

opened a can of spam

 

[John in CR]

Sevconone,

Any motor can be overheated and burned up. With a mid-drive there's really little excuse, because you're able to vary the gearing with different sprocket sizes to match the gearing with the load. Just look at the size of the motors required for golf carts and their performance limits to achieve durability. Then look at the performance you were asking with a much heavier vehicle, first from a motor 1/3rd the size and then a motor 2/3rds the size. Failure was guaranteed from the start, and that's where electrics should always enjoy an advantage...durability and zero maintenance. Selling a lead pig, albeit nifty looking, with an undersized motor does nothing to forward the cause.

Your buggy needs dual motors and lithium batteries, and then I'm sure it would be fine for street use. Offroad use requires a lower gear, because slogging thru the mud, or low speed ascents would melt dual motors. Below about 50% of top speed under load, whether it's during acceleration or offroading, is horribly inefficient, and every bit of power drawn from the battery and not turned into work is turned into heat in the drive system.

John