battery

wattage EQUALS voltage TIMES amperage - It's Ohm's Law again! 40 amp fuse + 40 amp fuse = 80 Amps 80 amps times 14.4 volts = 1152 watts I have a real tough time believing that your amplifiers are 87 percent efficient. Are they digital? If not, they are lying to you, they are NOT a 1000 watt amplifier. Fill us in on the brand name of them, and we will let you know... A cap WILL NOT FIX YOUR PROBLEM!!! Let me restate that A CAP WILL NOT FIX YOUR PROBLEM!!! You must start with your alternator. Then multiple batteries, THEN add a cap, if you feel so inclined. And yes, a 3.5F will probably do what you "need" it to do, but only after addressing the power SUPPLY first. A #4 cable is safe, fused at 150 amps. As far as the larger alternator, get the biggest thing you can afford that will go in your car. You won't be sorry.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."