Electrical Upgrade: Which one first? High Output Alternator or Batteries.

[SmartAsss 10+ year member]

Scenario: 1500w+ sound system is causing the lights to dim. Due to a high current demand, voltage drop is happening.

The correct thing to do first is...

A) Upgrade the factory alternator with a high output model.

B) Add more batteries.

C) I don't know, I'm hoping there are enough intelligent members to make this poll will give me the correct answer.

Im using this for profiling purposes. Lol

Click to read more...

 

[DBz Hertz 10+ year member]

What do you drive?

 

[95BlackGA 5,000+ posts]

Add a second battery first, or upgrade to a better battery up front. No matter how good your alt. is, it will still take time to spin up, and supply proper amperage/voltage.

 

[daboyfrumdabx 10+ year member]

What kind of battery do you have under the hood and what condition is it in?

 

[Redlineaudio 10+ year member]

do you pound it all the time or some and then no some. makes a big difference in the answer.

 

[azphat12 10+ year member]

Is the Big 3 upgraded?

I would start there.

 

[ahole-ic]

Add a second battery first, or upgrade to a better battery up front. No matter how good your alt. is, it will still take time to spin up, and supply proper amperage/voltage.

Hilariously false.

Dimming comes during the voltage drop from the alternator output voltage of around 14.4v to the battery resting voltage of about 12.6v. The only reason the voltage drops is the current drawn is higher than what the alternator can provide. No matter how many batteries are added, the voltage they rest at never increases so they can NEVER stop dimming. Only adding an adequately sized alternator can stop dimming. There are no ifs, ands, or buts. People that say otherwise do not know what they are talking about.

 

[SmartAsss 10+ year member]

Im not looking for an answer to my own electrical needs, I'm simply seeing how many people understand the basic concepts of a cars electrical system.

ecrack shush, don't give away the answer lol.

 

[solidcrowd 10+ year member]

Why does adding a battery or replacing the existing one upfront with a larger one stop peoples lights from dimming though?

 

[SmartAsss 10+ year member]

Why does adding a battery or replacing the existing one upfront with a larger one stop peoples lights from dimming though?

It never has, hence why you always see people posting threads like, "why are my lights flickering, I have 1-2-3 batteries, etc.."

The lights will stop flickering because their amps draw so much power that the alternator is no longer keeping up at all, the voltage drops to the battery's voltage at that point the battery is supplying a steady stream of the power to the system, lights stop flickering, lights are dim but not flickering, but if you read the voltage you will be looking at a low voltage of 12.6 or less. This would be a voltage drop. this is what we are trying to prevent. It would be akin to just disconnecting the alt, or turning the car off.

Simplified,

When the lights are flickering, its because your alternator is bouncing between its normal 14v+ charging voltage and the battery's 12.6 resting voltage. trying to keep up.

Once the alternator is way out of its league, then the lights stop flickering and you will just have a low voltage situation. Adding another battery only makes the alternator have to put its current into an additional device compounding the problem.

A low voltage situation is hell for the alternators rectifier diodes, and its voltage regulator. because more current is constantly flowing through them. this heats them up, and eventually kills the alternator.

make sense?