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Amp limit Magic Pie 5 kit

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Toeffen:
Hi.
I just wonder what the amp limits are on the Magic Pie 5 kit.
I have the 48v 10ah aluminum casing battery.
The motor is 30 amp max?
I have read both 20 amp and 30 amp on the battery.

I know the default is 25 amp. So that is the recomended.
But where is the bottleneck?
How much can the different components handle?

I might buy a second battery. So if I connect them in paralell, they can give 40 amps. But I guess that will burn the controller?

Any thoughts?


I also wonder what version of the software can change the max rpm higher than 380?

Thor

Bikemad:
Hi Thor,

I use LiPo packs that are capable of delivering a continuous 150 Amps with a peak discharge of 300 Amps, but the Magic Pie's controller will limit the current to ~30 Amps maximum even though the available current output of the battery pack is 5-10 times higher than this.
I suspect the 20 Amp and 30 Amp figures for that 10Ah battery are the constant and peak output figures. If you try to pull more amps than the battery can supply, the battery's BMS will typically cut the power to prevent damage to the battery.
If your battery is not cutting out under load then it is able to supply the required current for the motor.

Using two packs in parallel will provide a slight increase in power and slightly more than double the range. As each of the batteries are only being subjected to half of the current being drawn, the voltage sag will be much less, therefore the power should be slightly improved. 
30A @ 52V = 1560W, whereas 30A @ 56V = 1680w (7.7% extra power at the same 30A current level because the voltage sag is less)

The Magic Pie motors are capable of handling a lot more than 30 Amps for short bursts with a high current controller:



Although I suspect the windings may heat up a bit after prolonged use at higher current levels, but I have not yet seen a Magic Pie with burnt out windings.

Unfortunately, setting the rpm higher than 380 rpm will not make the motor any faster as it only reaches ~360rpm under no load conditions using a fully charged 48V battery with a voltage output of ~58V.

To achieve higher rpm you would need to fit a higher voltage controller and use a higher voltage battery pack.

Alan
 

Toeffen:
So both the controller and the battery will stop at around 30 amp without taking any damage. And the motor can handle atleast 50-60 amps?
I may want to increase the wattage later. And then I got 2 options using the Mp5 I already have.
Buy another one on the front wheel. Or change the controller.
Need a new,  or extra battery for both options.
The cheapest solution would be to change the controller. But the built in controller was one of the reasons I bought the Mp5.

I know that it cant do more than ca 360rpm now. But still want to be able to change it :)

Thor

DriftTrike:
Does anyone know if the mp5 software can be hacked to change the max rpm? Maybe a software guru can chime in?

Bikemad:
The maximum rpm can only be increased by increasing the battery voltage or changing the physical layout of the stator windings.

Unfortunately the MP5's internal controller would need to be replaced with a suitable external version if you wanted to use a 60V, 72V, 84V or higher battery pack for higher rpm and faster road speeds.

Alan

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