When to upgrade your alternator and or battery?

[GuysIGotThis]

Hey guys, I'm no expert in Car audio but I have done a few setups. I recently bought a "big" setup, I'm sure it's pretty small compared to what most people run but I'm just wondering if I'll run into alt & battery issues...

I have a 2007 civic Ex, the stock alternator puts out 90 amps. The battery is bran new (although it's not a yellow top or anything bought the battery before I decided to do the sound system)

Regardless I'll be doing the big three upgrade but I'm actually pretty concerned if I may have gone a little too big.

What i'm running:

Headunit: Pioneer UAE - Car Entertainment, Home Audio & Video, Headphones, DJ Products

Speakers: Car Audio & Video | Visions Electronics

Speaker Amp: Car Audio & Video | Visions Electronics

Subs: Car Audio & Video | Visions Electronics

Sub amp: Car Audio & Video | Visions Electronics

don't judge me on my sub woofer choice, I know it's the dark side.

TL/DR version of specs

Headunit: not sure the draw

Speakers: 75w rms x 4

Subs: 400 rms x 2

Amp 1 70w rms x 4

Amp 2 1000 rms (note I won't be running this full because it's overkill for my subs)

Do you guys think i'm screwed in terms of draw? I really appreciate the insight guys

Click to read more...

 

[shammyhavik]

The links don't work

 

[Boomin_tahoe 5,000+ posts]

1000 watts for sub I would do at least the big 3 first before spending $ on a alt or batt.

An aftermarket alt is ideal but be prepared to break out the checkbook as prices on them have gone up. Expect to pay anywhere between 300-700. Unless you can find a used one, which is possible, you might save yourself some $$.

Typically alt 1st then battery. I say battery 1st because a lot of us are on a budget.

 

[brian84corvette 10+ year member]

the fastest way to check if your draw will match what you have is this simple math trick.

100 watts of stereo power = 10 amps.

your alternator makes ___ amps and add the amp hour rating of your battery s to that = your avalable amps to use. x10 = watts avalable.

its a stupid simple math formula that adds up correctly every time to have "a little more than the bare minimum needed" to run your gear safely.

so

your alternator 90 amps on a good day / your battery being generous 50 amp hour rating. 90+50 = 140 amps x10 = 1400 watts avalable posibly

get a good 100 amp hour agm battery in there and it would be 90+100 = 190 amps x10 = 1900 watts avalable

then minus what your car uses to run the fans / electric fuel pump / fuel injectors / spark plug crap bla bla bla

you gettin the drift of how it calculates ?

 

[n2audio 5,000+ posts]

I don't see a huge concern.

We can play with numbers all day.

By far the biggest factor is how you listen.

If you're blasting it at the verge of clipping (or worse) all the time it's going to draw a ton of current relative to your 90A alternator, and probably burn it up in a few weeks.

If you listen at low-moderate volume most of the time with the occasional "crank it" session - I would expect you'll get at least a couple years out of it. That's the pattern that's developed for me running ~1500w rms with 110-130A alts for the past several years.

Personally, I wouldn't do anything with it right now.

Big 3's a good idea.

I would get familiar with your HO replacement options. With a car that common they should be numerous and not that expensive.

When the time comes to replace the stock alt you can decide at that point if it's worth it to go HO (future upgrades?).

Or if another couple years out of a stock replacement is the way to go.

Brian suggests a big battery gives you instant improvement in available current - which may be true, but that current is available at