Does anyone know if it would be necessary to replace the "stock alternator" for the scion xb , for a higher "crank amp" producing alternator because Im planning to put in a system in my xb within a couple of weeks, yet I need to know if the stock alternator would be okay and to know how many crank amps it produces because man Id hate to later on find out that the xb lights start to dim, the flickering or future electrical burnouts , Id really hate to deal with the headaches later down in the future......

 

You don't need to upgrade your alternator.

www.caraudioforum.com Search for "the big 3" do that. If you still have problems, consider a new battery.

 

scionseeker it depends on how much of a draw your system will use...i have to upgrade my alt as soon as i can afford it just because the stock alt puts out 80amps thats enough to cover the car and manybe 5-10% more at full draw...my stereo at full draw will pull 130+ amps so do the math sometimes you can get by with your stock alt and a big 3 with a 1 farad cap (caps arn't solutions there just a band aid for a problem that will resurface later)...if your thinking about upgrading your alt look into getting the stock one rewired most shops can bump the output atleast to 160amp for about 250 dollars or so and a week or so with no ride

 

You can also run a second battery on an Isolator just for the system. So if you're at a show and the battery dies, the main battery for the car still starts and will charge your system battery.
Jason

 

this would work also but the added battery would add unwanted stress to the stock alt

 

We will use a heat beam we invented called a "laser" to punch a hole in the protective layer of the atmosphere called the "ozone layer" ...


Sorry i couldn't resist

 

This is a good info, But if you are going to go big or add a 2nd battery you should upgrade your alt. The stock one will work for a while without a problem. But a old tale of the house built on sand.. Build it right the first time and you wont regret it.

 

Depends how much power you using and how long you'll be going full blast while engine is on.

When I first started off I got two PPI Amps that put out 1400 watts each. Not some Lightning Audio/Audiobahn amp, this thing put out it's POWA!

Blew my alternator in my 99 accord which was like a 130ish amp alternator.

Replaced it with a stock one and replaced stock battery with a Stinger(lower impedance than Optima). Ran around 2000 watts again with no alternator failure, but I didn't pound the subs as hard 24/7.

Adding second battery alone is not enough. Someone above mentioned an isolator which keeps your alternator from working too hard with the second battery.

DO NOT GET A CAPACITOR. They are for show. Go to carsound.com and do a search, you'll see.

 

adding a second battery will cause more of a drain on the stock alternator... even with a charging isolator...

multiple batteries are mainly there for show vehicles that will play there systems for long periods of time with the engine off...

most amps with a ~60 amp draw will most likely have a great draw on the stock electrical sytem. if you plan on getting an amp with that high of a draw i would
recommend running the thickest guage wire possible to the rear of the car and upgrading the alternator...

 

There is a lot of confusion about this topic but Ohm's Law can help us here. The amount of current demand your system will have on your charging system depends upon the amp and your listening habits.
First lets look at what your vehicle needs to run. Depending on which and how many accessories you are using, you vehicle will need 40 - 60 amps to operate.
Lets say you were planning a 1000 Watt system. Current (amps) = Power (Watts) / Voltage. So lets's plug this into the formula: 1000 Watts/12.5 Volts = 80 Amps.
This is not the whole story however. The number above assumes the amp is 100% efficient, but it's not. In the real world most designs are about 50% efficient when you factor in clipping. This means it will need 2000 Watts to generate 1000 (yikes). So lets see: 2000 Watts/12.5V= 160 amps plus the 40-60 amps you car needs, you need a 200 - 320 amp alternator just to feed your system....or do you?
You are the other factor. Your listening tastes dictate how much of that available power you are going to use with music. Most people will use 20% of the amplifier's power on average with music:
1000*.2=200 Watts (average)
(200*2)/12.5=32amps (average)
If you are like most people, you probably will not need to change the alternator if it's healthy.
Abusive poeple will use 50% of the amplifer's power on average with music:
1000*.5=500 Watts (average)
(500*2)/12.5=80amps (average)
Probably should upgrade.
The major difference between these two types of listeners is the amount of clipping they will drive their systems to. Most people will drive their systems into clipping, some more than others. Clipping dramatically increases average power.
There are other factors that influence average power like Crest Factor of recordings but that is a different discussion.

 

my lights hella dim when i'm jamming, i'm running 2 12" kicker L7's in a custom ported box with the kicker 1200. amp

 

calm down with the booming r you're going to need a new alternator

 

i can either upgrade now or when it blows

 

Question is: Do you want to have your car not start at 3AM after you get out of the nudie bar?



Upgrade now, if they make em yet.

 

I've seen some place selling hi-output echo alternators, would they fit the xb(they have the same engine, don't they?)

 

i would definitely do the big 3 upgrade in atleast 4 awg, then upgrade the battery to a deep cycle such as a yellow top. at this point you shouldnt be having any probs at all. i would stay away from caps cuz they dont make power, they take power and its just one more thing your system has to charge (even though its a very short charge). upgrading the alt should be the last thing on your list.

How much actual power(RMS) are you planning on running?