Voltage drop/alternator question

[bottomline2000]

its probably a 130 amp alt, when i first bought my tahoe i was running about 3000watts RMS on the stock alt with the big 3 and 1 extra battery in the back just fine. Get an extra batt in the back first then go from there. Our stock alts are great compared to some tiny ones that come with other vehicles.

I'm curious to know how you did this. My system is like 1400rms running a JL1000 w/ a w7 and another 4 ch JL amp. My system could literally stall my truck if turned it up loud enough with the stock 130a alt. Did you run an isolator to the 2nd battery? my 275a alt solved the problem, but I'm still thinking about adding a second battery.

 

[NoPh33rRaCiNg]

I'm curious to know how you did this. My system is like 1400rms running a JL1000 w/ a w7 and another 4 ch JL amp. My system could literally stall my truck if turned it up loud enough with the stock 130a alt. Did you run an isolator to the 2nd battery? my 275a alt solved the problem, but I'm still thinking about adding a second battery.

I was running a redtop up front and kinetik 2400 in the back. And I was running a DC Audio 3000.1

You coulda had bad grounds, alt going bad, not sure what batts you were running etc..

 

[sparg93]

Not to sound difficult, but I'm still not sure how adding a second battery is going to help with voltage drops due to a weak alternator...second batteries are typically utilized so you can turn your truck off and still run the stereo & lights; or you have a mega system with multiple alternators.

If you have an undersized alternator, now you have two batteries, one isolator and extra wires to now run electricity through...seems to me it would cause even further strain on an already weak alternator.

Again, not trying to sound difficult...but I'm interested to hear how a second battery would help in his case.

 

[bottomline2000]

I was running a redtop up front and kinetik 2400 in the back. And I was running a DC Audio 3000.1

You coulda had bad grounds, alt going bad, not sure what batts you were running etc..

I was running a yellow top battery. All JL wiring with JL connectors amd the system was professionally installed not a DIY. My 1000 seems to just draw a lot of power.

I'm with sparge in that I don't understand how adding a 2nd batt would make things better. I'm game to try, but it just seems like the alt is still power the system when the truck is running. Please enlighten...

 

[NoPh33rRaCiNg]

Not to sound difficult, but I'm still not sure how adding a second battery is going to help with voltage drops due to a weak alternator...second batteries are typically utilized so you can turn your truck off and still run the stereo & lights; or you have a mega system with multiple alternators.

If you have an undersized alternator, now you have two batteries, one isolator and extra wires to now run electricity through...seems to me it would cause even further strain on an already weak alternator.

Again, not trying to sound difficult...but I'm interested to hear how a second battery would help in his case.

His alterantor is not really weak, our stock 130 amp alts are huge compared to some that come in civics that are like 70 amps etc...

That amp he is running only pulls 90 amps at most, it has 3 30 amp fuses on it. And he is not even running the amp at full 2 ohms, he said its wired to put out 800 watts rms which i read the specs on that amp and it does 800 rms at 4 ohms. It does even more at 2 ohms.

If he had a bigger amp like a 3k that had 300 amps worth of fusing id say upgrade the alt, but i have personally ran 3k off stock 130 amp alt, big 3 and one extra kinetik 2400 in the back.

 

[sparg93]

completely agree - he should not see a voltage drop on a 130amp alternator (which is why my original thought is that he had 100amp) with that setup....my question is more regarding the use of a 2nd battery.

Actually - OP - what RPM are you idling at? when was the last time you cleaned your MAF?

 

[blueflamed03]

i think adding an upgraded alt would be a better idea. sometimes adding a secondary battery is more of a drain on the electrical system. it in essence has to work twice as hard and some times causes alt failure. a second battery is great for extending play time with the key off, but with the engine running you need more voltage, say running at 14.4 and more AMPS to supply the system. if you add up how many amps you are using vs how much your alt puts out, you'll see how it wont be enough

It wont tax anymore than what he is already doing. The alt will charge the battery that is in more need of extra current. Another battery is like $80, an ** alt is like a coupel hundred up to $400, depending on unit and windings.
Its no more drain then pulling a ton of juice from the main battery.

 

[sparg93]

It wont tax anymore than what he is already doing. The alt will charge the battery that is in more need of extra current. Another battery is like $80, an ** alt is like a coupel hundred up to $400, depending on unit and windings.
Its no more drain then pulling a ton of juice from the main battery.

But then he'll still have a alternator not putting out enough energy and be $80(which is a really cheap battery) poorer...

 

[waxworkz]

It wont tax anymore than what he is already doing. The alt will charge the battery that is in more need of extra current. Another battery is like $80, an ** alt is like a coupel hundred up to $400, depending on unit and windings.
Its no more drain then pulling a ton of juice from the main battery.

You obviously don't know ohms law?adding a second battery is effectively dubbing the drain on an alternator. Electricity will not flow like water, to the emptiest location. It flows path of least resistance, so if you have more wiring run, battery in back, it will not charge as much as the from battery. Due only to the amount of wire, read resistance, the electricity has to travel.

I managed and installed professionally installed sound systems for over a decade, so I'm no DIYer. I would still recommend upgrading alt before battery. Think of it this way, why do manufacturers install larger alternators in high end, luxury cars with dual ac, fans, lights, electric everything? Would adding an $80 battery be more cost effective? It's because the battery is only for starting a car and smoothing the current from the alternator. If you rely on a battery for power, to a stereo system or factory system, you will kill the battery. Optima or kinetik doesn't matter, batteries are not meant to supply amperage above starting. Unless you are running a demo vehicle and use a power supply to charge and power the system for long periods.

 

[blueflamed03]

Not a noob either, work for such a manufacture.( 23 years actually) An alt will prove the same current. Sure, a more ** alt will add more power, but you run all external addons like sound system lights, etc off the secondary battery. That way your starting system is not hampered by all the extral add ons pulling too much voltage. While maybe not a perfect scenario, by all means much cheaper and with a proper regulator, will suffice in many cases.

Dont have to trust what I say, alt companies love people to reccomend a $400 alt...OP can by all means go buy one.

PS: higher output alts came out when car manufactures started adding more power accessories. The old days of the 105a are about gone.

But looking back on what amp you are playing, I really dont see why you'd have hug dips in voltage. I have more power than that on a stock alt....and no issues.
Check to make sure your factory alt is working like it should, and you have good connections.