if i want to hook up 2 PSU's to one amp where does the ground go for the other PSU.. i dont think it would be intelligent to connect it to the other psu's ground.. soo yeah..my amp is 14.4V @ 40A and the one PSU im using now is 12v @ 20A so would another PSU li9ke i have now work? with amps is it 20+20=40 or 20+20=20? thnaks for any input