The design utilizes large copper areas on the PCB and CNC-machined brass bus bars to minimize internal resistance, typically measured at just 120–170 µOhm .
Resistance spot welding requires high current (800–1500 Amps) for a very short time (5–15 milliseconds). If the pulse is too long, the heat spreads and burns the battery cell. If the current is too low, the weld is cold and brittle. kweld schematic
This ensures the MOSFETs switch from "fully off" to "fully on" in microseconds. The faster the switching time, the less time the MOSFET spends in the "linear region" where it generates the most heat. The design utilizes large copper areas on the
Switching a MOSFET that handles 2000 amps is not as simple as sending a 5V signal from an Arduino. The schematic reveals a sophisticated stage. If the current is too low, the weld is cold and brittle