fitting of second battery

[TehSniper]

my plans for my audio in my megane will eventually include the fitting of a capacitor and a second battery. the reason for the fitting of these items is that i will eventually have 4 amps in my boot (dont ask how still planning that one :P) now for the fitting of a second battery i was wondering if just running a second power cable from the positive of the main battery to my second batter and earthing the second battery (wherever i put it) would be enough. would have have to upgrade the alternator or would the extra charge that it creats be abough to keep both batterys topped up. now the other issue is wether i have posted this in the right area :P any advice is greatly apprciated and i will get pictures of the finished product when i have all the money and spent it on all i am doing

[davelowe]

First off, you need to determine the median RMS input power consumption of the finished audio system. Details...

[TehSniper]

6x9s
RMS Power: 100 watts
Peak Power: 300 watts

12 inch sub
RMS Power: 300 watts
Peak Power: 900 watts

10 inch sub
RMS Power: 250 watts
Peak Power: 750 watts

10 inch sub
RMS Power: 250 watts
Peak Power: 750 watts

there the stats for the speakers that are going to be amped

[anth_dci]

thats going to sound VERY bassy

[TehSniper]

not really, all depends on how im gonna set up the amps. plus im sorting the normal speakers in the pannals today so there will be plenty of tweet

[-KJ-]

You CANNOT just connect a second battery to the first battery! You'll need a separation relay and a connection to your alternator, like installations in campervans. Go to a decent caraudioshop for advice.