Boosting amps as voltage drops puts extraordinary stress on components. The higher the conversion ratio, the more heat is produced and conversion efficiencies decrease. Thats another reason I love those huge 32650’s that can sustain a continuous huge load without sag. So far, Im quite impressed with this driver.
Ive been using copper pipe strands, 12 gauge solid core copper and end pieces from noctigon/sinkpads die stamps to cool mosfets and diodes. Although the data sheets often show many of these components as being able to handle high temperatures, if its made in China… all bets are off. Sink those (potentially shitty made suckers) before you push them beyond.
In other lights, regardless of what others have indicated as being a “tough mega driver”, enough have failed that I always sink the hot parts. IMO, potting insulates most hot parts and shortens component life. If its hot, sink it with copper, using the copper as a heat conductor to transfer heat to an exterior sink. Its easy to do and will definitely increase longevity. If she goes poof, then look forward to your new mosfet driver swap.
BTW, those TF 32650’s are definitely worth the money. Ive been running the crap out of them in my stock TK70. 3 cells and an additional spring with copper wire & disk mod launches the boost driver into DD, and that sucker keeps up with my modified BTU shocker with XML2. Im just as impressed with those cells as I am with the TR-J20. In fact they are THE ONLY Chinese made cells I have ever been impressed with.
Looking back on my 9 x XML comparison vs this 12 XML chunky, Id take the 12X any day. While the 9X is driven much harder, its a meager “wow light” that edges out the 12X in terms of raw lumens, but it overheats FAR too quickly to be of much use to anyone that expects to use it for any length of time. IMO, a wow light has some purpose as a pocket EDC, but not as a monster bashing continuous burn beast… enter the TR-J20.
For your mod, if you have any concerns, decrease your resistance in increments and see how hot the mosfets get. I assume you have the driver dismounted from its home while testing, so also check the board to see how hot its getting. Being dismounted from the sink will prevent it from conducting heat, which will skew your observations. I doubt the tail switch will prove to be a weak link.