Author Topic: No power on Magic Pie 5  (Read 6094 times)

Offline Bikemad

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Re: No power on Magic Pie 5
« Reply #15 on: January 17, 2019, 01:33:15 PM »
To remove the cooling fan and controller, make sure you use an Allen key and screwdriver that fits properly as the countersunk bolts/screws can often be very tight to undo.
I prefer to use hex drive bits like the one shown here:



If the bolts/screws are really tight, and you feel that you may strip the head of the bolt, you can insert the bit and then hammer directly on the end of it, and the shock of the hammer blows should encourage the bolts/screws to loosen.  ;)

Some cheap Allen keys can be made from very poor quality steel and they may damage the hexagon head on the inside of the bolt head if it is forced too much and the key slips.

Also make a note of the phase wire positions on the old controller so that you can put them back in the same position on the new controller.

If the new controller has not been set to the correct battery voltage by the supplier, you may need to adjust it using the USB programming lead or Bluetooth dongle before the motor will run.

I apply a small amount of Silicone sealant (or just smear some Vaseline petroleum jelly) around the flange of the controller to help prevent water getting in.
I also grease (or Vaseline) the threads of the steel bolts to prevent them from seizing into the Aluminium hub.

Alan
 

Offline Kim

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Re: No power on Magic Pie 5
« Reply #16 on: January 20, 2019, 07:14:53 PM »
Thanks for the tips. Hopefully have it changed over in the next few days.

Are there any tips for lessening the likelihood of shorting the controller in the future? If I turn off regen breaking and reduce the draw to 20 instead of 25 would that help? Does battery voltage come into the equation? It shorted when I was using a pretty old batter that probably wasn't running at the optimum voltage.

Offline Bikemad

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Re: No power on Magic Pie 5
« Reply #17 on: January 21, 2019, 12:00:13 PM »
Regen seems to be the most common link with controller failure, so turning off the regen should definitely help.

The controller can also be damaged if the battery is suddenly disconnected (or not connected/switched on) while riding at high speed, so make sure there are no loose connections on the main battery supply cables (or the switch) that could intermittently lose continuity on bumpy terrain etc..

The maximum battery drawn current should be set slightly lower than the battery's continuous rated power output to prevent the BMS from suddenly disconnecting the battery from the controller while it is under load. The controller's Low Voltage Protection Value should ideally be set slightly higher than the Low Voltage Cutoff setting of the Battery's BMS, as this will also help to prevent the BMS from disconnecting the battery while under load.
The controller will automatically reduce the amount of power going to the motor if the battery voltage drops down to the controller's Low Voltage Protection Value and should prevent the battery voltage from going below it.

Alan