EECiv

iTrader: (1)

Come reading week I want to get everything set up and will be running 300-400 watts for highs and ~1400 watts to the sub.

Being i'm running a civic with very small battery under the hood i want to add a second one in the trunk. Therefore i need to know anything and everything to hooking up a second battery in my trunk

anyone with experience your input will be greatly appricated. do and don'ts are always helpful! thanks again!

Steve

Rockney

Well for starters you want to fuse the wire you run from your front battery to your rear battery at both ends. I would run a 4 gauge wire between the 2 and use about 150-200 amp fuses for your application.

EECiv

iTrader: (1)

Is that all i need to do? I already have 2 gauge running back there for my power wire that I could use. So i need to fuse this near the battery at both ends. And then do I run my power for the amps from the battery in the trunk? I've already looked into the saftey behind it and plan to have it securtly in the trunk with a homemade cage of some sort around it.

Anyother tips / suggestions?

hawg_hauler

iTrader: (3)

You might want to invest in a good quality battery isolator, unless you plan on purchasing two identical batteries and installing them at the same time. You can use the 2 gauge that is already in the car. Also consider using a gelcell type battery, it is the safe way to go.

Hardwrkr

iTrader: (5)

Remember that a second battery is going to be an added strain to your alternater. If you haven't already done so you may want to look into a high output unit.

MR2NR

iTrader: (66)

The gel cell is a must for the internal battery as it does not explode nor give off noxious odours (thus the requirement to vent to the outside for a normal battery). It is also a missile in an accident and needs to be held down very securely.

Rockney

Yes fusung at both ends is highly recommended,, then if your power wire between the 2 batteries groungs itself out it will blw the fuses and not the batteries

MR2NR

iTrader: (66)

Or start the vehicle on fire.

Fever

iTrader: (1)

How about the ground?
The only 2nd batt install I've seen had the 2nd batt grounded at the spare tire well centre hub.
He said it worked fine.
So you don't HAVE to run a 2nd grd wire b/w batts?

Phiber Optik

Do you use the stereo with the car off a lot?
If so then a second gelcel battery grounded to the frame with isolator and 'big 3' upgrade will work.
If you are just looking for some more juice for daily driving then I suggest upgrading your alternator and 'big 3' wiring.