Magic Pie 3 Regen braking not working

[ElectricStreet]

This bike has a 48V power pak.  And the user lives on a mountian.  So the braking is important and used alot.  I checked the brake lever and the switch is functioning properly.  I then checked the voltage at the front connector harness and shows a strong 4V current. Could the amount of braking cause the feature to blow out?  Are there any fixes?

[ElectricStreet]

I guess it's a controller issue.  Unless its some parameter of the controller.  Does anyone know where I can find a controller adapter for the Magic Pie III?

[Bikemad]

I am a bit puzzled as to which motor you actually have, as in one of your posts you refer to a Magic Pie 2 and in another you are trying to program a Magic Pie 4, yet this thread clearly states Magic Pie III.

Do you have three different motors or is this simply a case of mistaken identity?   

If it were an MP4 I would check for a brake switch wiring fault by unplugging each brake connector in turn and trying the regen function with just one control connected to see if it makes a difference, as it is highly unlikely that both brake levers would have faulty wiring.

If it is an MPIII, you will still need to make sure you get the correct USB programming cable with the matching connector to suit your motor as there are two different versions (8 or 10 pin). Perhaps Gary (GM Canada) will be able to supply the a suitable USB programming cable.

The MPII's 8 pin connector is also slightly different to the MPIII's 8 pin connector. 

Alan
 

[ElectricStreet]

It's a MP3  and I have built three bikes so far.  The first was a MP2 then an MP3 and the latest is the MP4.  So, back to my problem. I had a controller adapter to initially program the MP3.  Then I gave it back and now I don't have one.  But, would the controller actually work then not work, because of something that changed in the controller?  Anyway, I'm really thinking now it's the controller.  Is it an easy job?  And, wondering if you can regenerative brake too much to actually damage the battery. 

[Bikemad]

If the controller operation is intermittent then it could be due to a dodgy wiring connection somewhere on the harness.
If the regen has been accidentally set to zero in the software, it might also explain why it is not working.



But, if you are still convinced that the controller itself is causing the problem then changing the controller is a relatively straightforward job, as long as the fixing bolts for the controller and the cooling fan/disc mount come undone OK.
I always use a good quality Allen key to reduce the possibility of the tool slipping inside the hexagonal sockets in the end of the bolts as they can sometimes be very tight.

Check out Gary's Magic Pie III Controller Swap video to see exactly what's involved.

Regarding tha battery damage question, if you are using a battery pack without any BMS protection that is only able to accept a low charge current you might damage the battery by using regen at high speed as the charge current produced by the regen may be too much for the battery.



If two of the 5200Mah Multistar LiPo packs shown above were wired in series, the 29.6V 5.2Ah battery would have a continuous discharge rating of 10C (52 Amps) and a 10 second peak discharge rating of 20C (104 Amps), but the maximum recommended charge rate for this particular pack is only 2C (10.4 Amps).
Two (or even three) of these packs wired in series would be unable to cope with the regen current from a Magic Pie. 

When I last measured the regen current on my Magic Pie 4 it produced just over 26A at only 20 mph.
 
Alan