how to wire 2nd battery?

ok so i have a great sounding system but my lights continue to dim. my system consists of 4 alpine 6.5", 4 alpine 6x9s, 2 audiobahn flame Q 12' s, 4 channel kicker 850 watt amp, 1000 watt alpine mono block amp, hu is alpine ica d310 flip out, audiobahn 12 farad cap, 0 ga wire from battery to cap an 4 ga to amps, optima battery (yellow top) under hood, 220 h/o alternator, upgraded the big 3 with 4ga wire. i am getting frustrated since my lights still dim an have a 2nd optima battery (yellow top) an put it in the trunk but not hooked up yet. ive seen alot of people have different opinions how to wire the 2nd battery up. can anybody help me how to wire up the 2ns battery so i get  the best way to get the most use out of the battery without putting any kind of excessive strain on any battery or alt? thanks

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TK

Forget "excessive strain". It is a load like any other.

If you are getting voltage dips, then you alternator isn't big enough or isn't reacting fast enough (so you dip to battery voltages), or the path is shared with whatever load is causing the dips.

The latter is only fixed by separating the paths to the battery or alternator or futher reducing path resistance. (I'd suggest ground paths - ensure they exceed the +12V cabling.)

Since you have a 12F cap, put that beside the lights (relay power) since that's not helping and it'll be useless with a local AGM battery.

The 2nd battery (AGM; Optima) should be like the cap - as close to the amp as possible.
The batt (or cap) cabling to the amp can be even heavier than the from the alternator/main-battery.

Presumably you will want independent batteries except when charging. If you have a charge lamp, use its (alternator) circuit to energise a relay that connects the 2nd battery to the main battery, otherwise get a voltage switch to energise a relay (or a "smart battery isolator" etc.
Most alternators will energise a typical automotive relay (15A-30A etc) and that can be used to energise a heavier relay is needed (eg - 150A, 400A etc).

And ensure you have protection (fuses or breakers) at each end of the battery interconnection cable.

Do a search and you should find various writings by me on such connectivity.

Or if independence isn't an issue, maybe take OptimaJim's & jmelton86's advice and just connect the batteries together (with the protection at each end) (not that I would hard-parallel batteries in this situation!).


Or fit a second alternator and run the two systems separately with a common ground. (Though the fist alternator can charge the 2nd battery if it isn't being used for the amps etc.)

I would upgrade the big 3 with 0 ga wire!

Dang! I forgot to mention that.
Too easy!

thanks for the help guys greatly appreicated

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TK

You might want to check all your grounds. Make sure they are solidly bolted to the frame not a barely mounted cross brace etc. Also you should use some dielectric grease on all your exterior connections. Anything under the hood or exposed to the elements. I recently took apart some power wires most were greased and they were spotless, the wire and the mating surfaces. But the one's I had forgotten had gotten corroded. So to keep good clean connections, use the grease. It's available in any auto parts store.