Stock OK or Need HO Alt and/or Batteries

[cas0586]

My vehicle has a stock CS144 140A alt and standard group 79 battery. Will running the equipment listed in my signature plus another HDS312 and 1200W likely require upgrades(other than the 'big 5' already completed.) If so suggestions?

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[C1500martin 10+ year member]

what car is it? my 90 c1500 couldn't run a sq2200 and q4-120 without HO alt and second batt. it all depends on the car itself. thats a pretty decent alt size though. whats you voltage dipping to right now?

 

[cas0586]

It's an Olds Aurora. It has a pretty stout stock alt.

 

[Kross6622 10+ year member]

From what I gathered your setup needs to sustain around 2000w. With that in mind, my recommendation would be to make sure your stock battery is in good shape, your alt is in proper working order, and adding an additional battery if you play extended demos. With proper recharging from your stock alt I see no issues with your setup from an electrical supply standpoint. Without the addition of extra battery, extended demoing will substantially decrease the life of your stock located battery.

 

[negolien]

Running a 2001 olds alero similar car I would go to a bigger alt if I was you.

 

[cas0586]

Right now the charging system doesn't bat an eye at the load.

If I were to add an extra battery it would be an isolated setup. So, the main/starting battery is isolated from the aux/audio battery during cranking and vehicle off. RV type setup. This should suffice I would think with the addition of the second HDS312/Q-1200D added in the near future.

Now as mentioned I still have a stock group 79 battery. It is in perfect health. It is maintained when vehicle is not in use. Can I parallel the group 31, 34/78 AGM with no ill effects?

 

[n2audio 5,000+ posts]

So you're doing ~1200 with the Cadence, ~1200 with the SQ and ~500 with the PPI??

No idea what your impedances are, but no matter how you slice it, that's a ton of power.

It doesn't make any sense to me why people always want to go straight to the batteries in a situation like this.

The issue is clearly the alternator. At low-moderate volume it's not surprising the alt performs fine. At high volume you should be seeing 12.5-13v a lot of the time -- still plenty for things to run fine in the short term.

Long term - your alt isn't going to last long UNLESS you're someone who RARELY blasts it.

Do what you want to do with the batteries -- looks like you have a logical plan with that, but assuming you like to turn it up occasionally -- you need to be HO alt shopping. That degree of current demand will generate a LOT of heat and the alt's life will be drastically shortened.

At 1500w my 130A ford alts were burning up every couple years. And I don't blast it very often.

That must be a very rare alternator. I'm not seeing a 140A replacement for that car, just the usual POS 105A.

 

[cas0586]

This is a Classic Aurora with 4.0L V8. I figure the second gen Aurora with the V6 has the 105A alternator. The V8 has the same alt that is in Cadillacs of the same era with larger 4.6L N*s. The CS144 140A is standard.

I do not have the second HDS312 or Q-1200D installed yet. So I do not know how the current setup would react. Likely not well. Adding the second isolated battery would allow me to run the stereo and carpc without draining main battery with car off.

As for blasting it. No it's not a frequent occurrence. --insert pic of car seat and ornery toddler--.

 

[TheFiverMan 10+ year member]

If this makes you feel any better. I run a sundown 2500d @ 1ohm with a stock alt. 105 amps yellow top under the hood (I Know its a yellow top but i got it for free) and a deka 9a31 in the rear. The lowest voltage drop I get full tilt at idle is 12.8-9. Driving full tilt lights and heater running 13.4-6

 

[n2audio 5,000+ posts]

If this makes you feel any better. I run a sundown 2500d @ 1ohm with a stock alt. 105 amps yellow top under the hood (I Know its a yellow top but i got it for free) and a deka 9a31 in the rear. The lowest voltage drop I get full tilt at idle is 12.8-9. Driving full tilt lights and heater running 13.4-6

Yes, short term, 105A and a healthy battery will act fine. Until the day the alt melts down and you're left stranded on the side of the road w/a dead battery.

Happened to me once with the wife, the 12 y/o and the 4 y/o in the car on a 99 degree 3rd of July. The fam wasn't super thrilled with me that day.

Stock alt's are sized to run at 40-60% capacity and last 5-10 yrs. At 90-100% they don't last long at all.

 

[cas0586]

What size high output alternator should I be looking for with the setup in my signature? Running main group 78 AGM battery and secondary group 34 AGM.

 

[cas0586]

...bueller?

 

[n2audio 5,000+ posts]

Big.

I'd probably start with 200A and see what's available. Sometimes it's not much more expensive to go to 220 or 250. The bigger the better.

For other cars finding ANYTHING is difficult, and custom builds can be a small fortune.