Magic Pie 3 Modification

[msmit551]

Hi,

I built a Magic Pie 3 powered by a 48v 10ah LiFePO4 battery into my bike a few years back and am now looking to upgrade to make things more interesting.

I intend to replace the unreliable internal controller with a 12 fet external from the likes of Lyen or CellMan. Also I will replace the phase wires with a larger csa and extend the hall sensor cables.

I have done a lot of research and have a rough idea on how this will be achieved. Just wandering if anyone on here has any experience of doing this and any advice or links to members previous posts.
I recall seeing several peoples threads detailing their experience with this a few years ago but the posts seem to have disappeared (manly interested in how to get larger csa phase wires out through the existing holes with little modification. ie not having to machine thinner bushings etc.)

Additionally to this I am looking to combine my old 10Ah 48v battery in series with another battery of the same chemistry in order to increase voltage. I have seen conflicting opinions on whether it is ok to mix batteries with different 'Ah' ratings. Can anybody see a problem with me using a 36v 10 or 15 Ah to achieve this?

Apologies for the mammoth post I know it's asking a lot.

Cheers,
Matt

[Bikemad]

Those post are still here, you just need to find them:

Ginge's thread

Scorpion's thread

Both Ginge and Scorpion used Alpha ecowire to extend their phase windings through the axle, but they had earlier versions of the Magic Pie and the wires had to fit though a small groove in the axle inside the bearing:



But the MPIII has a lot more room for the wires:





Using batteries with different Ah ratings in series is not recommended and the lower capacity battery could suffer.

Adding another 36V 10Ah battery should be OK if they have the same chemistries (i.e. LiFePO₄ or LiMn etc.) but it is recommended to add suitable diodes to protect both of the battery's BMS circuit boards:



Alan
 

[msmit551]

That's exactly what I was looking for, thanks Alan!

[msmit551]

Well, went ahead and made the modifications still running on 48v at the moment but the extra current from the Lyen controller is impressive! Now to build the extra 48~v pack to add in series...