Fw3x problems

Anyone have any idea why I would be having issues when using a Samsung 25R (15A) battery with the FW3X? It will come on for a couple seconds and start to ramp up, but I can’t even get it to stay powered on. Works fine with Samsung 30Q (10A)

My FW3A shows similar symptoms unless the head is tightened down as much as possible after tightening down the tail first as much as possible. Also cleaning the contacts in the tube head seems to make a difference too. This is irrespective of the battery I’m using unlike your case.