im running one air zenith with an 85 amp cont. duty solenoid from napa i got an 85 amp justin case i wanted to run two it sould be enough. also im running #4 wire from the bat. to a block with a 100 amp fuse in line to protect it from a direct short from the block to the solenoid i ran a #8 which is almost a foot plus the ground and a switch to turn the comp on and off manually. havent had any problems yet and it my daily