mppts use big inductors to convert voltage, and when they suddenly become unloaded, the inductor energy has nowhere to go, which can cause a voltage spike at the output. a well designed mppt can catch it before damage. also if your inverter is still connected to the battery bus when the battery fuse blows, the inverter will sink the energy spike with no potential damage. from personal experience i have tripped my battery overcurrent protection many times with no damage to my victron mppt
