I recently got my PP+3000 units. Took 4 months to arrive. After charging the battery i hooked it up and sure enough my Ampzilla 2000 monobloc amps hum very loud. No hum thru the speakers, just out of the amps. Have contacted PP and they had me run a number of experiments (removing interconnects, speaker wires, etc)and they promised to work on fixing the problem. But after all of the broken promises experienced in the past 4 months, and hearing the disapointment of others using this product, i'm not going to hold my breath.