How to control very very really very high currents with arduino?

Grumpy_Mike:

I'm working in a discharger of LiPo batteries that must discharge at rates of 100 amp

So is this an incendiary device then. What is to stop the battery bursting into flames?

There are special Li-Po packs that are designed to supply that kind of current discharge (for a short time of course) used in high performance R/C electric motor powered craft.

Lefty