I have not personally clamped mine but this is a clamp test done from a member of Soundpressure in Europe
Battery + power supply
3805w @ 4,60 Ohm (start volt 14v drop to 12,9v)
6250w @ 2,30 Ohm (start volt 14v drop to 12,4v)
9550w @ 1,15 Ohm (start volt 14v drop to 11,9v)
So it's not to bad for one amp on a 12v system