Will my alternator handle my audio system?

[nik_72]

I have a 2010 ford focus and I will soon be adding a sub. I have read online that some car alternators can't handle large amp.

Now I haven't decided if this is the exact items I will go with but the specs around what I want.

Amp-

Alpine MRP-M500 Mono subwoofer amplifier — 500 watts RMS x 1 at 2 ohms at Crutchfield.com

Sub-

JL Audio 12W3v3-2 W3v3 Series 12" 2-ohm subwoofer at Crutchfield.com

Already in the car, I have installed 4 6x9 kicker speakers in the doors (can't remember the specs) and when I install the sub I will be adding a double din head unit.

Now to the main question, will my alternator be able to handle the sub/amp without effecting the electrical system? I searched on the internet and from what I can find, the stock alternator has an output of 120 amps. It that enough to handle everything in the car without damage to the battery or alternator?

I know people maybe suggest a cap but that only cover a big hit and not a constant draw, right?

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[vibe]

what kind of power accessories do you have in your car?

 

[nik_72]

what kind of power accessories do you have in your car?

I added interior after market led lighting and there's phone charge, that it lol

 

[jrdnhsnbrg 10+ year member]

You should be fine. A general rule of thumb is typically you don't want more than 2k on a stock alternator. Caps are useless, get a second battery if you need to. I believe someone is selling an XS Power D925 on here for a steal, it's small but will definitely help if you're having dimming issues.

 

[vibe]

I added interior after market led lighting and there's phone charge, that it lol

im not too familiar with what the output is going to be on the led lighting. phone charger is probably not very much. i think if you were to do the big 3 you should be fine. thats not a bad size alternator for stock. you can always buy a voltmeter and install that too and if your voltage is going low i.e 12v area when the bass is hitting than your going to need an agm or a h.o alternator but in my experience im thinking you will be just fine if you do the big 3 in 4 gauge ofc wire

 

---------- Post added at 10:25 AM ---------- Previous post was at 10:24 AM ----------

 

You should be fine. A general rule of thumb is typically you don't want more than 2k on a stock alternator. Caps are useless, get a second battery if you need to. I believe someone is selling an XS Power D925 on here for a steal, it's small but will definitely help if you're having dimming issues.

**** i wish i could have gotten 2k on a stock alternator. i could only get around 700 on mine. crappy 90a alt though.

 

[vibe]

and yes caps are completely useless. one of the dumbest ploys and wastes of money ive ever seen.

 

[jrdnhsnbrg 10+ year member]

im not too familiar with what the output is going to be on the led lighting. phone charger is probably not very much. i think if you were to do the big 3 you should be fine. thats not a bad size alternator for stock. you can always buy a voltmeter and install that too and if your voltage is going low i.e 12v area when the bass is hitting than your going to need an agm or a h.o alternator but in my experience im thinking you will be just fine if you do the big 3 in 4 gauge ofc wire 

---------- Post added at 10:25 AM ---------- Previous post was at 10:24 AM ----------

 

**** i wish i could have gotten 2k on a stock alternator. i could only get around 700 on mine. crappy 90a alt though.

It can be done if you do it right, and by that I mean a lot of big batteries. My stock alt is 140a, bigger than some peoples "high output" alts lol

 

[vibe]

It can be done if you do it right, and by that I mean a lot of big batteries. My stock alt is 140a, bigger than some peoples "high output" alts lol

yeah that is true. im in the midst of getting 4 xs power batteries and having a 2 h.o alternator setup so i get the lots of batteries.

 

[CrossoverOre 10+ year member]

you will be just fine using that amp on a stock setup.