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Discussion Starter · #1 ·
hey guys,

I was wondering of anybody knows if the alternator mounts on the 2012 altimas are the same as the new 2013's. I cant find any high output alternators that fit the 2.5 for the 2013's and i am looking to add a second sub to my car. or maybe the 3.5 alternators fit (probably not)

Thanks
 

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09 Altima 3.5SE 6MT Sedan
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Are you sure you need a bigger alternator? I would think a bigger battery is actually what you are looking for.

A 110A alternator in theory can put out over 1300W of continuous power. What is the current draw from your existing audio system? My guess is it averages less than 300W---that's a true guess...I have no idea what you have, but it does mean the alternator can easily replenish the power used by your audio system with a kilowatt to spare.
 

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Discussion Starter · #3 ·
Are you sure you need a bigger alternator? I would think a bigger battery is actually what you are looking for.

A 110A alternator in theory can put out over 1300W of continuous power. What is the current draw from your existing audio system? My guess is it averages less than 300W---that's a true guess...I have no idea what you have, but it does mean the alternator can easily replenish the power used by your audio system with a kilowatt to spare.
actually i have a massive sound system. Right now i am pulling 1000 watts rms to my one single sub at 2 Ohms. and with all of the other electronic power needed for the car, i can obviously see my headlights dim and such. Also, i have a 3.0 farad capacitor in the car but honestly capacitors don't really do anything. im definitely going to need another alternator and probably a new battery in the future
 

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09 Altima 3.5SE 6MT Sedan
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Please measure the actual current being drawn by your sound system in amps when in use. You'll need an amp clamp style meter since I doubt you'll find anything that will work in series.

Adding a mere 20A of generating capacity won't stop your headlights from dimming, you need more reserve power to handle instantaneous need, not more average power. So you store 'charge' in a battery (high capacity, medium release rate) and capacitors (med capacity, high release rate) for when it's required (such as a massive excursion of your sub diaphragm). You optimize charge delivery by using high capacity cables (thick) and storing charge as close to point of use as possible. The larger your battery the more on-demand power that is available, the closer your caps to your amp, the more instant-on power that is available.

The fact that your headlights 'syncopate' to your beat is proof that storage/delivery and not generation are the problem. If generation was the problem, your battery would eventually be fully drained and no longer able to start the car even with the engine running.
 

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I had a large system like yours in my last car, a larger battery fixed my dimming issue.
 

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09 Altima 3.5SE 6MT Sedan
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The other thing is to make sure you have the best ground possible on that battery...so make sure both ends are clean, shiny and dry contact. I would even use a little copper based antiseize between the neg cable and the chassis. A Big-3 grounding mod would also be something to consider with that new beefier battery.

Also, when hunting for a battery, you are looking for the best Ampere-hour rating, not the best 'Cold Cranking Amps'. Ah is a measure of how much power it can store, CCA is a measure of how fast it can be delivered (roughly volume vs pressure as an analogy). You need volume more than pressure, you will deal with pressure with your capacitor(s).
 

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Sorry to revive if this post is considered dead but I'm in a similar boat.

I also have an aftermarket audio system, currently drawing 1000 watts (CEA-rated watts, not Wal-Mart watts)
I have a Kinetik HC2400 (gel-cell iirc) battery in the trunk, obviously wired in parallel.

I don't have problems with power, but I've been running the system this way for a couple years and can notice a decrease in SPL after running the system at high levels for an hour or two straight.

I'd also like the power system to be able to handle up to a 3,500 watt net load from the audio system alone.

I read in the manual that our 2013+ gens have a special computer that manages charge, and it measures something at the negative terminal of the battery. I'm thinking this will affect how we approach doing a big 3.

Insight. I want your insight, oh tenyar veterans of the Nissin realm.

2013 S Sedan
 

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hey guys,

I was wondering of anybody knows if the alternator mounts on the 2012 altimas are the same as the new 2013's. I cant find any high output alternators that fit the 2.5 for the 2013's and i am looking to add a second sub to my car. or maybe the 3.5 alternators fit (probably not)

Thanks
In response to op, no, I don't think 2012 parts will fit our 2013's. We're a new generation! ?
 

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Are you sure you need a bigger alternator? I would think a bigger battery is actually what you are looking for.

A 110A alternator in theory can put out over 1300W of continuous power. What is the current draw from your existing audio system? My guess is it averages less than 300W---that's a true guess...I have no idea what you have, but it does mean the alternator can easily replenish the power used by your audio system with a kilowatt to spare.
Are these numbers for our 2013 2/2.5L's d0ugmac?
110A is generous for a 2 litre
 

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Please measure the actual current being drawn by your sound system in amps when in use. You'll need an amp clamp style meter since I doubt you'll find anything that will work in series.

Adding a mere 20A of generating capacity won't stop your headlights from dimming, you need more reserve power to handle instantaneous need, not more average power. So you store 'charge' in a battery (high capacity, medium release rate) and capacitors (med capacity, high release rate) for when it's required (such as a massive excursion of your sub diaphragm). You optimize charge delivery by using high capacity cables (thick) and storing charge as close to point of use as possible. The larger your battery the more on-demand power that is available, the closer your caps to your amp, the more instant-on power that is available.

The fact that your headlights 'syncopate' to your beat is proof that storage/delivery and not generation are the problem. If generation was the problem, your battery would eventually be fully drained and no longer able to start the car even with the engine running.
Just to save you the effort of making sure I read the whole post, I took an ASE certification class at my local community college for funzies.
The day we studied power systems, one of my buddies "nominated" my car to demo alternator current measurement.
It read about 183A, but this was in my old vehicle with an aftermarket H/O alt.
Same battery, wiring, amp,and subs though.
 

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I love the explanation.

Reminds me of when hybrids first came out, how they were one of the first consumer vehicles to reclaim previously lost power by converting kinetic energy from the momentum of deceleration to electrical via the alternator.

I still don't understand what the device connected to the negative terminal does though.
 

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I love the explanation.

Reminds me of when hybrids first came out, how they were one of the first consumer vehicles to reclaim previously lost power by converting kinetic energy from the momentum of deceleration to electrical via the alternator.

I still don't understand what the device connected to the negative terminal does though.
Nissan Altima Owner's Manual, Section 8, Maintenance and Do it yourself section, Variable Voltage Control System:

Your vehicle is equipped with a variable voltage control system. This system measures the amount of electrical discharge from the battery and controls voltage generated by the generator. The current sensor is located near the battery along the negative battery cable. If you add electrical accessories to your vehicle, be sure to ground them to a suitable body ground such as the frame or engine block area.

It is amazing that useful information is contained in the Owner's Manual.
 

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I love the explanation.

Reminds me of when hybrids first came out, how they were one of the first consumer vehicles to reclaim previously lost power by converting kinetic energy from the momentum of deceleration to electrical via the alternator.

I still don't understand what the device connected to the negative terminal does though.
Nissan Altima Owner's Manual, Section 8, Maintenance and Do it yourself section, Variable Voltage Control System:

Your vehicle is equipped with a variable voltage control system. This system measures the amount of electrical discharge from the battery and controls voltage generated by the generator. The current sensor is located near the battery along the negative battery cable. If you add electrical accessories to your vehicle, be sure to ground them to a suitable body ground such as the frame or engine block area.

It is amazing that useful information is contained in the Owner's Manual.
That's perfect.

But how would we do negative to ground as a part of a big 3?

Going from the end of the sensor to chassis instead of negative terminal to chassis will allow the sensor to continue doing its job, but what current is it rated for? Maybe not as much load as a system with aftermarket components would impose.
 
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