i want to have an extra battery in my boot of my ford xf so i can run my amps and and neons of it so it doent drain the power of my normal battery.
does anyone no a good and cheap way to put the extra battery in the boot

Well you need to run some heavy wires down the back, then you need a thing (cant remember what its called ) that will charge that battery as well as your main battery but wont allow the front battery to be used should the 2nd one go flat (ie always means you'll be able to start your car, mostly for campers etc)

Get what I mean - you're best bet is to head to an auto-elec and he'll have the parts etc and either get him to do it or buy the bits and save yourself the labour!

Well you need to run some heavy wires down the back, then you need a isolator that will charge that battery as well as your main battery but wont allow the front battery to be used should the 2nd one go flat (ie always means you'll be able to start your car, mostly for campers etc)

Get what I mean - you're best bet is to head to an auto-elec and he'll have the parts etc and either get him to do it or buy the bits and save yourself the labour!

You should probably just get a higher amperage alternator.

From what I read, the EF has the best alternator of pre AU cars... 120amp I think it is... 10 more than the EL and 35 or more amps than the earlier falcons.... perhaps graft one of them in for some extra juice.

we used to do dual batteries for people.. you need an isolator as mentioned and also a dry or gel cell battery.. no gas can get into the car from the battery so needs to be done properly.

Will depend on the gear you choose to run but unless you plan on running the system for lengthy periods when the car is off (or any other auxilleries) then a 2nd battery maybe needed.

You can run them together in parrallel or via a relay/isolator - this is the preferred method incase one battery faults (such as no longer holds charge and will put further strain on your alternator/working battery trying to trickle charge and top up the faulty battery) also as you run all the auxilleries such as stereo gear of the 2nd battery the isolator prevents the main 'starting' - cranking battery from being depleted and unable to start the car.

The EF/EL higher spec models -ghia's, xr's etc all came factory with a 110A Mitsubishi/Bosch alternator so if your XF's runnig a 60 or 80A unit it'd be worth upgrading the alternator too.

Also if your planning on going dual batteries make sure you only run identical models....and if you current batteries just a run of the mil century etc maybe look at one large capacity high output battery such as an optima yellow top or odyssey.