New Alternator Install Questions

[ericnord]

Hey everyone,

After upgrading my stereo my X now requires more power. I have a 220amp alt. on the way and I had some questions about it.

1. To accomodate for the increase in amperage I will run some 1/0 gauge wire from the output of alt. directly to the pos. post on battery. I will also leave the stock wire from the alt. output to the fuse box. Is this the right thing to do and should I fuse the 1/0 wire run, if so what size fuse?

2. Is there something inside an alternator that tells it when the battery needs power? I don't want this large alt. blowing up my battery by feeding it too much power.

3. Since I am running the 1/0 wire to battery, must I also do the "Big 3" upgrade? I would rather not and this alt. will be plenty of power for my system.

Thanks for any help,
-Eric

 

[GSEREP1]

Yes there is: It is called the voltage regulator. This device is both voltage and amperage sensitive. The older voltage regulators used to be on the firewall, but now they are built into the alternators.

BY the way..ALTERNATOR is the correct term, because the device produces A.C current, and the diodes inside convert it to DC power for the battery and all accessories.

A GENERATOR is a DC voltage device....(produces DC voltage when it is spun), but requires more rpm to get the same voltage out. In the old days, we all had generators on our cars, and the engine speed had to be held above idle in order to get power from it, or the "generator" light would come on until the engine speeded up...remember that anyone? I am 52, and I can remember it.

An alternator can put out max current at idle engine speed due to its' design. The voltage regulator increases field current strength to the windings, and output goes to "maximum" immediately. Once the battery is charged fully, field current is reduced, and output goes to practically zero. This is on a GOOD battery.

A BAD battery (cracked, leaking, or dead cell), will cause an alternator to work too hard, because it is trying to charge the dead battery, and as such, it burns up.

A properly working alternator will NOT overcharge your battery regardless of the amperage size. Just be sure the regulator can handle that much current. An internal regulator on a 220 amp alternator is properly sized to fully charge the battery without burning up anything.

In fact, the alternator will produce just enough current to run the accessories in the car once the battery is fully charged. The battery is used only for voltage regulation, and to start the vehicle.

Alternators are MUCH MORE efficient. There hasn't been a GENERATOR installed as standard equipment from the manufacturer in any car for over 30 years.

GSEREP1

 

[ericnord]

Thanks so much for the info. What about the wire run and the fuse?

Also, who said anything about a generator? I said Alternator all along.

Thanks again,
-Eric

 

[cherrybomb]

Unless the wire from the alternator to the battery goes through a body panel, or is otherwise in danger of shorting to a ground, you need not put a fuse it in.

The reason for a fuse, when running a wire into your truck for an audio system, is that since it runs through a hole in your firewall, if for whatever reason the vibrations etc cause the firewall to cut through the wire, and it shorts, you don't want current to continue flowing through it. Otherwise, the wire will become extremely hot, and catch fire.

A fuse prevents this from happening, by "popping" at a set load. So if a dead short happens, and 100 amps are going through the wire, the fuse breaks, and stops the current from flowing, and getting the wire hot.



Sounds like a good little upgrade your doing. What brand alternator you get? How much it cost?

Also, what is the "Big 3" upgrade you mentioned? Never heard of it..

 

[ericnord]

I purchased the alt. from the groupbuy on here and sounddomain.com. It caost me 230.00 for 220amp.

The big 3 is were you upgrade the wire size to make sure all the power is getting around your electrical. You run a wire from alt. to battery, you run a wire from ground on battery to chassis, and another from ground to engine block. Something along those lines, it helps increase current flow so you can make sure you are getting maximum transfer of the current.

-Eric