Alternator

[Panda KO]

I have Hifonics BRX2400.1D Brutus going to run 2 HDS315's running all 2400watts. Someone told me my stock Alternator wasn't going to handle it right. I have a 130a alternator will it be good enough? If not what would I need to keep it safe and no light dimming?

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[Dub7sonoma Premium Member]

I have Hifonics BRX2400.1D Brutus going to run 2 HDS315's running all 2400watts. Someone told me my stock Alternator wasn't going to handle it right. I have a 130a alternator will it be good enough? If not what would I need to keep it safe and no light dimming?

130a alternator will be ok if you do the big 3, upgrade the battery up front and add 2 batteries somewhere else. Preferably group 31s but anything with at least 100ah each

 

[Jeffdachef 5,000+ posts]

I have Hifonics BRX2400.1D Brutus going to run 2 HDS315's running all 2400watts. Someone told me my stock Alternator wasn't going to handle it right. I have a 130a alternator will it be good enough? If not what would I need to keep it safe and no light dimming?

If its D4 subs wired to 1 ohm then you only need to do the big 3 upgrade and a big 2nd battery in the back and you'll be fine.

If your planning on getting D2 subs and wiring it down to 0.5 ohm, you might need an agm under the hood and a 2nd battery in the back.

 

[gstokes]

hmm, 2400 watts divided by 12 volts = 200 amps..

it'll bump but you're over 70 amps short of reaching your goal..

 

[Dub7sonoma Premium Member]

hmm, 2400 watts divided by 12 volts = 200 amps..it'll bump but you're over 70 amps short of reaching your goal..

That's if the amp was 100% efficient, plus you have to figure in what the car is going to be using from the alt just to run and drive.

 

[Panda KO]

ok thanks

 

[Godzilla311]

I've been out of the car audio game for a while (since late 90s), but I know cars and electronics--wouldn't adding more batteries be counter productive to creating higher wattage while the engine is on? More batteries means a bigger load on the alternator which means less power when the car is running. More batteries, on the other hand, would create more power when car is off.

To get more power with the engine running you'd need a bigger alternator.

Either way, id say run it and see how it works before investing in anything else. Lights dimming isn't much of an issue in my opinion. My lights have dimmed for 15 years and my battery has only dies at the drive in once. Granted I've never ran over 500w rms, but my car also only has an 80amp alternator.

 

[Dub7sonoma Premium Member]

I've been out of the car audio game for a while (since late 90s), but I know cars and electronics--wouldn't adding more batteries be counter productive to creating higher wattage while the engine is on? More batteries means a bigger load on the alternator which means less power when the car is running. More batteries, on the other hand, would create more power when car is off.
To get more power with the engine running you'd need a bigger alternator.

Either way, id say run it and see how it works before investing in anything else. Lights dimming isn't much of an issue in my opinion. My lights have dimmed for 15 years and my battery has only dies at the drive in once. Granted I've never ran over 500w rms, but my car also only has an 80amp alternator.

Adding more batteries does put a bit more strain on an alternator. But if you were just running off of an alternator without additional batteries, the amp would be pulling all of its power from the alternator. Additional batteries will help share the load with the alternator. Another risk with trying to run a bigger amp off just an alternator is when you use up all of the alternators output and still try to pull more amperage..... what happens.

 

[bubbagumper6 5,000+ posts]

Gah, so much misinformation in one thread it's sad. Please don't offer advice unless you really know what you're talking about, and just because you read something on a forum once doesn't mean it's true!

Batteries do not share the load with the alternator, period.

Most batteries rest at around ~12.5-13V while most alternators charge at 14-14.5V. So while the car is running the system voltage is over 14V, anything that's below that system voltage (i.e. batteries) can only be a LOAD on the system, they cannot SUPPLY anything, they can only consume. So with the car running 100% of your power comes from your alternator provided it can provide that power.

Now, where batteries come into play is if your alternator CANNOT provide that power. If you try to draw 200A from a 130A alternator, it's obviously not going to be able to keep up so the system voltage falls. Once the system voltage falls to the battery resting voltage they will begin to supply the system. This is VERY HARD ON YOUR ALTERNATOR though and will cause it to fail prematurely.

Once this condition is over and the amplifier is no longer drawing more than the alternator can provide (i.e. the particular bassnote is done) the system voltage will rise back to the alternator voltage and at this point the batteries are once again a drain on the system, much more so than before because now they've been discharged somewhat and need to be recharged.

 

[negolien]

Pretty simple imo an alternator say a 220A and the big 3. All the people getting the XS and Optima batteries make me laugh. Unless you're mounting them funny or using more than 1 battery a good solid normal battery is fine.You don't need 3 batteries all that craps pointless in a daily driver...Just my opinion.. It's amazing how much difference the Big 3 makes but running that many watts yes I'd say a HO alt would be a good call.

 

[BoomTaco64]

so having multiple batteries does not help in any way when having a high wattage stereo for "daily" use?

 

[mylows10 5,000+ posts]

so having multiple batteries does not help in any way when having a high wattage stereo for "daily" use?

It does. But not as much as you think. The batteries still need to keep their charge. If your amp draws more power than the alt can produce it's just a matter if time before the batteries are completely drained. You can recharge them periodically. But it's not as good as having the ho alt to recharge them while driving

 

[BoomTaco64]

i would have to call some bs on this....i have a toyota tacoma with a 2.5kw amp when i was only using the factory batt and alt with big 3 i had voltage drop to below 12.5 on big bass notes. added a kinetik HC2400 next to my amp and have not seen a voltage drop below .5v only going as low as 13.9v now. so with my personal test, having the extra battery is more beneficial that what you are stating. been the same kinetik and stock alt (4cyl truck 2wd) for the last 3years in the hot as $hit state of AZ where batteries generally only last one summer.

 

[mylows10 5,000+ posts]

In actuality @BoomTaco64 ; most cars can take up to 2000 rms on a stock electrical with just the big 3 but there are a few exceptions to this yours being one like my truck but let's get real here 2500 rms after rise and resistance you may not even be getting half that I have the system in my sig. And I can get down to 11.5 at idle if demoing my system. But at 2000 rpm down to 12.8. And I have 8 batteries and a 275 amp alt but I also have close to 10k before rise