Run my fet switched green PT120 maglite aspherical direct drive with 4D Tenergy 10,000mah NiMH batteries. According to Lambda data this setup is capable of 30A fresh off the charger. The real beauty of NiMH is the long flat discharge power curve.
My easiest red PT54 maglite build was using the stock switch with 18ga wire soldered to emitter negative, heatsink providing positive ground (install batteries backward), 2 Tenergy D NiMH batteries, copper braided tail spring. 9A to the emitter and decent run time. Modes? Don’t need no stinkin modes!