Yes, i searched but came up with no luck. I was thinking of adding a second yellowtop to run my audio but im a bit confused on how to go about it. Do you just connect it to the main battery and if so how. Also how would this battery recharge via the alt.? Any input would be greatly appreciated.

 

I was thinking to just run the 2nd battery independently, but I think you will have to tie the second battery into the alternator.

 

i use a stinger 1000 under hood
and 3 stinger 680's in the hatch

run a 0 awg or 4 awg depending on how much flow you need i would just do it once and use 0 awg heavy duty power wire


off your under hood battery your positive factory terminal has an accessory bolt to mount a 0 awg ring terminal

depending on what your amp or amps fuses add up to fuse the power wire with the proper atm , atc , anl, or agu fuse

then after your fused run it into an isloater relay remember to ground and trigger the relay i suggest a stinger isolater relay

then off the relay into cabin and to hatch

now run the power wire to another 0 awg ring terminal connect to positive terminal on the 2nd battery in your hatch ( i would go stinger and not optima )
run a 0 awg ground on ring terminal from negative hatch battery 15 " to raw metal with no paint

now connect the same hatch battery terminals - & + to a distribution blocks
one distribution block for the + and 1 for the -

then from blocks to amp or amps - and +

 

Each battery is designed for a certain type of load - there are batteries designed for the high current demands of starting and there are batteries designed for deep discharge over long periods of time. Using one battery in place of the other will work but shorten the life and function at a reduced level.

Using a solenoid between the starter battery and the auxiliary batteries can allow you to start the motor off of one battery and then connect them together for charging both. You connect your stereo load to the auxiliary battery system so that when the car is parked you disconnect the starter battery from the stereo system's drain. You don't look cool needing a push start or a jump after the party. If the auxiliary battery drains to the point that the stereo system stops you simply start the car off the starter battery and let the party continue while the second battery charges.

So this system typically has a two mode switch allowing you to enable or disable the solenoid as you desire. In the off position the aux batteries are disconnected, in the on position they are connected only once the car is started.

Some systems have a three mode switch which will all the car to start off of both batteries as if they were connected together in one system as suggested above. That's going to put high current/short duration loads on the auxiliary battery which will shorten its life. 4x4's will use this mode as they'll use their starter battery and alternator power to supply the massively high requirement of a winch - 7000 watts or more in some cases. The alternator supplies 120-180 amps and the poor battery gets sucked dry often to the point where the truck will not start. Throw the switch into mode three, wait a few minutes for the aux batteries to discharge into the starter battery and then start the motor back up, let the truck run for several minutes to all the winch to cool and the battery to charge and then go back into mode one splitting the two batteries up again.

HTH Paul

www.painlessperformace.com
http://www.texasindustrialelectric.com/relays.asp

 

Paul, Nice explanation… That’s exactly how I setup my 1990 off-road Montero: Two Optimas connected with a battery management controller. That setup allows using a big electric winch and some flood lights (for cleaning pheasants or gutting an antelope in the dark) with no worry of draining the battery needed to start the car.

But, my old Montero has lots of room in the interior (where I mounted the battery management/controller by mounting it under the dash) and the engine bay (where I mounted the dual Optimas).

I’m not sure how you could fit these (the controller and the second battery) in a Z. I suppose you could fit the second battery in the trunk (Roadster) or rear (Coupe), and place the controller in the DD space (if you replaced the stock H/U with a single-din H/U and lower shelf) or even in one of the rear (behind the seats) cubbys.

--Spike