Two batteries?

A fellow came into my shop. He wants to load up his nissan maxima. He wants a second battery in the trunk for his four subs, and he says he has two caps he wants installed. (He has a seperate amp for his highs and one for his mids. Where do I put the battery and the caps and how do I wire them?

ok u need two power distribution blocks for this, one should have 2 inputs, the other can just have one input but it must have at least 3 outputs. so he has 3 amps right?  ok  the two inputs on the first block are one for the battery under the hood and the other for the second battery.  just ground the second battery.   the output on that block goes to one of the caps (positive end of course), then just daisy chain to the next positive end of the 2nd cap, and then daisy chain it again to the input of the second block.  ground first cap, and daisy chain to the other cap.  the three outputs on the second block, go to the 3 amps...and just ground all 3 amps! im pretty sure this is right...someone correct me if im wrong.

also wont a bigger alternator be needed? but your explanation looks correct.Quad L Handyman services

BTW, if it hasn't already been said, make suer that the battery in the trunk is a dry cell battery and that you vent the gases outside the vehicle. Otherwise there is a possibility of an explosion from built up exhaust gases from the battery. Better safe than dead Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

How would I vent the gases? Thanks for all the input

If you purchase a Optima battery there are two discs on the top of the battery that have plastic tabs on them. These are venting discs . What I have donein the past is made plexiglass covers for these and used small gauge clear tubing ( air line hose ) and attached them to these plexi discs and ran the hose to the vents in the trunk to the outside of the vehicle.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA