Author Topic: Magic Pie II with externel Controller, maybe controller and Motor broken  (Read 4422 times)

Offline samsamsam

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Hello

I have a Magic Pie since autumn 2011. I drove now 3000 km with the motor, and had already broken a controller in winter, a capacitor was broken, exchange of the capacitor has not helped. Now the controller is broken again. One or two FETs are burned.
Both controllers also have solder balls, were the most likely cause short circuits.

Before the final controller was broken, he has only been working at half capacity, has a maximum of 30km / h and the whole bike will vibrate when set off and when it is over 33 km / h.
Hopefully, only the controller is broken.

Just for general information only.
I have a 48V battery with sixteen Headway 16A cells with a 30-60 A BMS. I load the battery at 15 A maximum of 1.5 hours at 58.4 volts. Engine is rear mounted into 26 inch City Bike. With Cycle Analyst.

The controller was programmed with 20 amps and 48 volts and in the original plastic case packed in the luggage carrier. very airy.
Braking power 90%.
My feeling is that the controller always broke, when I drove half hour or longer at full throttle and then I slowed down considerably, as if the controller, when it is hot first, no longer tolerate brakes.
Now arises the question for me, will I once again invest in a GM Controller.

If the controller is in an aluminum case with fan perhaps?
Are there any reliable controller?
Do I need to rewire anything new for a different controller, plugs and so on?

Important to me is slow down with the engine, saves brake pads and brake performance is great. Braking distance is only 6m from 45 to zero km/h.
From a performance point I would like to have a little more power. Because uphill at about 15km / h with the controller 20A setting the controller use only about 10A.

The charge of the battery during braking would be nice, but if it could harm the battery, rather not.
The first controller has loaded back to the battery, but still has only about 5% more coverage brought by Cycle Analyst.
The newer controller has not reloaded, but he has also slowed down at low speed very well. What I found very enjoyable.

Basically, I'm very happy with the controller but unfortunately it breaks down too quickly. In addition, solder dissolves and causes short circuits.
The capacitors are designed only to 105 ° C. But 65 € per controller is again relatively cheap in comparison to others.

What is your recommendation? A other controller.
Or maybe two GM controller as a reserve and a aluminum box with a fan. Maybe problems with fan in the rain.

Thank you
Sam

PS:. My english is not so good. I live in Austria, Europa

Offline Bikemad

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Now arises the question for me, will I once again invest in a GM Controller.

If the controller is in an aluminum case with fan perhaps?
Are there any reliable controller?
Do I need to rewire anything new for a different controller, plugs and so on?

Important to me is slow down with the engine, saves brake pads and brake performance is great. Braking distance is only 6m from 45 to zero km/h.
From a performance point I would like to have a little more power. Because uphill at about 15km / h with the controller 20A setting the controller use only about 10A.


Sam, the Lyen (Infineon) controllers seem to be very reliable and would provide more power and a faster top speed.

You would need to change the connectors, but as you already have the external controller, it makes the process of converting to a different controller a lot easier than it would be for an internal one.

The first controller has loaded back to the battery, but still has only about 5% more coverage brought by Cycle Analyst.
The newer controller has not reloaded, but he has also slowed down at low speed very well. What I found very enjoyable.


I recently fitted a larger 50 tooth chainwheel on my bike and tested it down the road without putting a battery pack on the bike, just to see how much higher the gearing was. It seems that the later GM controllers have a different Regenerative/Electronic Braking System to the earlier ones, as the motor's strong braking effect actually cut in when I braked from a high speed, even without a battery being connected! :o

I went for a 3.5 mile ride yesterday with the dog and connected a pair of watt meters so I could monitor the current flow in both directions.
I was rather disappointed to find out just how low the regen measurements were on the watt meter. I had actually used 2.162Ah from the battery, but regenerative braking had only put back 0.010Ah (0.46%) after I had ridden down a long steep hill using only regen to maintain ~7mph because the dog simply refused to go any faster.

I must therefore assume that the majority of the low speed braking energy is simply being wasted, as the maximum regen current was only 3.67 amps (98.1 watts) and this included braking to a standstill from at least 15mph at the end of the trip.

The dynamic braking effect with the later controller seems to remain more effective down to a much lower speed than it did with the earlier controllers, but this appears to be very inefficient as it is wasting a great deal of the available kinetic energy.

Alan