Not enough power :(

[kcpwns]

well...my current setup consists of;
2x Kicker solo baric L7 12" subs
Option audio 2000wrms mono amp
and kicker speakers in the car soon to be powered by
a Option Audio 160wrms x 4 Chan amp
And I will be adding another Option Audio mono
block so the subs have one each.

Now my optima yellowtop powers everything fine...until i sit at idle rpm...only lasts a minute or so before the headlights start dimming. I also cannot have the stereo playing with the car off or else it drains the battery within 20 or so minutes and want start back up.
I went to a bloke in town who specializes in batteries and I am guessing has general knowledge of auto electronics. Now after testing my battery and confirming it wasn't faulty he said the alternator is obviously stressed from the excessive drainage plus the age of it probably doesn't help.
Anyway he suggested a bigger optima and a dual battery system with a bigger alternator and get a dc to dc charger to help the alternator out.
Does this sound plausible? He seemed to know his stuff and I was just wondering on some of your opinions, like is all that necessary?? Will i even need a second battery or bigger alternator? Dont really know much about auto electronics so willing to learn.
Kinda stuck at what to do..should I follow through with it...
I haven't done the big 3 yet but I will be when i get around to it.
Cheers guys.

[aaronevolution]

Dual battery will at-least stop your car from dying.

[acarmody]

Out of curiosity, why are you adding another mono amp, the 2000wrms amp is more than enough.

[one_and_only2004]

Out of curiosity, why are you adding another mono amp, the 2000wrms amp is more than enough.

That's what I was thinking as well.
Dual batteries isn't going to help you whilst you're at idle, all it does is delay the time it takes to go flat - what you need is either a new alternator or a bigger one.

[sweefu]

Or upgrade the cables properly first, in my opinion there is no real point exploring any other options when you have an ~8awg cable going from your battery to your alternator charge point, same for your battery ground.

[Nic92]

what size wire do you have on the mono amp to bat?

[kcpwns]

Ive seen my subs with 1500wrms to them each and they go off...
either way its still draining now lol..
Ive only got 2 gauge from battery to amp..upping that to 0
once it comes in...its on order...and Im doing the big 3 most likely with 0 gauge aswell...
But I am going to need a new alternator I guess...what do people with commodores do
to get a bigger alternator?? Because I keep hearing about putting v8 ones in
but I havent read or seen it done...

[acarmody]

From what I can gather fitting a V8 alternator requires custom brackets to be made. Honestly you might as well go a goo 200amp alternator if your going to that much trouble.

Also I wouldn't feed 1500wrms into each sub, it might handle it for a bit, but then they will crash.

[kcpwns]

hmm...the second mono block isn't really locked in as yet..just an idea...
cant really spend money on it if it's not running properly...
My mate is a fabricator...so if I get hold of a 200amp alternator?? somehow lol..
and I get brackets made up and fit it etc...would this class this as an engine modification?
I am a p plater so cops kinda like hanging out with me on the side of the road.

[acarmody]

Alternator can be bought from any decent auto sparky, the 200amp one are generic ones.

I can't see it being an engine mod, its not part of the engine, its a accessory, and it will actually decrease the power of your car, only by 1 or 2 watts.

Keep in mind though, it will only make 200amps at full turning speed, have to get that of the manufactorer, it won't make 200amps at idle, but then you current one won't make 100amps at idle.

[kcpwns]

yeah I already kinda knew the rpm vs alternator amperage...anything would be better then the
worn out stock v6 one I have now though...
It is tax time so I think my plan of attack will be;
Source a new alternator, Big 3, New wire to mono block and install the 4 channel amp
and see how I go from their...hopefully that will fix the problem...
Oh and probably neaten up my boot install...kinda plain at the moment.

[acarmody]

You would be better off just running 0-gauge to the boot, and from a distributor, 0-gauge to the mono and 4-gauge to the 4-channel amp.

Depending what wiring you have now, you can cut that up and use it for the Big 3 wiring.

[kcpwns]

I was gonna run 0 to the boot then t to both amps...
Don't have any cable ATM I have ordered some so just
Waiting on that...I'll probably end up getting more anyway for
The big 3...
Damn money pit of a stereo lol

[Nic92]

hey, are them l7s ported or sealed ?

[acarmody]

hey, are them l7s ported or sealed ?

If anyone has sealed L7s they deserve to be shot, LOL. They are very much suited to ported, but we will see what the kcpwns says, while I prepare a gun just in case.

@Kcpwns, what cable do you have going to the mono at the moment?

[Crisis63]

I wouldn’t think cable is the issue at this stage as that would affect the systems performance, not result in dimming headlights. It sounds like the system is hogging the power so it is getting enough juice. Check the current draw, measure the current the system is drawing with music at the level you listen and I think you will find you may need a bigger alternator and perhaps a higher rated battery. Ideally a larger alternator and a second deep cycle battery.

[one_and_only2004]

Drawing large currents through a small cable will make the lights dim - it's called voltage drop.

[Crisis63]

Drawing large currents through a small cable will make the lights dim - it's called voltage drop.

Yes but the voltage would drop for the equipment drawing the current. As the lights are dimming that would point to current drop at that point however as they don’t appear to be changed it is unlikely they would be drawing excessive current.
In this case it looks like the sound system is drawing current in excess of what the battery and alternator can keep up with and it is affecting other accessories. The writer has not mentioned the current draw manifesting itself as an issue with the sound system therefore there does not appear to be a problem with the current being supplied to it. I would definitely ensure the cabling is sufficient but as I said the only way to make sure is to measure what it is drawing.

[one_and_only2004]

Yes but the voltage would drop for the equipment drawing the current. As the lights are dimming that would point to current drop at that point however as they don’t appear to be changed it is unlikely they would be drawing excessive current.

No, it'll drop voltage for the entire installation (hence why house lights dim when you're starting up a decent sized air compressor or something with a motor when the cable isn't up to scratch).

[wrx884]

y dont u re new ur regulator 1st or find out that its up 2 scratch b4 u buy a whole new alternator? could b all it needs along with the Big 3 upgrade.

[calais_cruzin]

Get sum 0guage n do big3

I very rarly get volt drop off 2200w and its only ever when ur idling n its pumping, mine only drops from 13.4 to 12.9 .5v drop

[wrx884]

Get sum 0guage n do big3

I very rarly get volt drop off 2200w and its only ever when ur idling n its pumping, mine only drops from 13.4 to 12.9 .5v drop

and uve only got an 85amp alternator in urs huh? which leads me 2 belive its the regulator.

[calais_cruzin]

Yeah im on stocko 85amp

Id still get the reg there what $35 max

But id still get 0guage run for the amp, batt grounds and alt charge n engine ground

2000w on 2guage over say 5m, its goin to drop especially with 8 guage batt ground

[kcpwns]

Lol at sealed l7's!! They are Ported...I think at 36hz?? It's what ever the factory
One is...
Mono block is only running on 2 gauge..but I'm scrapping
That for 0...so I'll have zero from battery to boot to a distributor then to
Both amps...
Well it's tax time so I'll be doing the big 3 anyways...it may fix the problem
I don't have any gear to check voltage drops...do you just use a standard multimeter?
I may invest in one...
I think I covered all the questions?

Thanks for all the input guys
I'm just trying to get it all running good...no point
Having big subs if you have boot rattle and dimming
Headlights lol

[Nic92]

you should set up a volt meter inside the car somewhere so you can see the voltage at all times, can get 1 for like 2 bucks on ebay lol, and yes you can use a multi meter to measure the voltage