wiring 2x controllers in parallel to....??

[Serum]

I would personally NOT use both controllers on the 12 cells, you must know that this setup will drain your batteries very quick, and besides, it will drastically shorten the lifespan of your cells. because you will be pushing them to the maxx.

You will find the answer in lipoly. And you will be pushing those lehner 4200's to the 60000 rpm with ease..