Audio Systems: rewirering to a seperate battery, car battries, ford explorer sport

Question
Ok i have a 2001 ford explorer sport and all my wireing is hooked up on the batt under the hood...i want to get another battery and rewirer it all in the trunk of the car....and i wana add some smaller things like eqlizers and stuff like that....can you help me out explaining the way i should wire it and what kind of other things i can hook up to make it louder....and what size voltage batt i would need just to pover my 1500 watt amp and two 12'' mtx subs...plz help me out on this one thanx...

Answer
Hi Robert,
Easy one at last, ;_)
280033378242 is the ebay number of the relay I would reccomend. 75a 12v
You need this as a split charge relay or if your second battery is flat and you try to start the car it will drag the normal one down and Urrrrr urrrr, thunk!
Take a 100 amp cable with properly fitted ring terminals from the plus terminal of your normal battery to the relay and from that to the second battery, earth the second battery to chassis, take a thin wire from the output when running (Ignition warning light) to the + of the relay coil and ground the other side. Now when the engine is NOT running all the power from the second battery will power whatever ??? without being connected to the main battery, when you start the car the alternator will connect and recharge BOTH batteries.
1500watts Hmmm big. 1500 devided by 12= 125 amp hr battery. O.K. so it would be good at 1500 watts for one hour without charging, work it out, diesel car battries are bigger normaly if your down the breakers yard.
Running off the second battery for, whatever?? Use a seperate fuse box or block used for hi fi hook ups and run everything from that.
Peter