The end all "what electrical system do i need" thread

[shizzzon 461]

I know you guys are.. and i am too...

Everyday.. every other day... 6 minutes ago... either here or elsewhere, people are ALWAYS asking how many batteries, is this enough battery, is my alt strong enough, how many alts will i need, etc....

Well... i've been meaning to say this for a while and it seems it's time now.

STOP PUTTING YOUR ELECTRICAL SYSTEM QUESTIONS UP ON A PEDESTAL!

Just because you may want to install 2,000w on stock electrical system doesn't mean it's immediately going to suffer catastrophic failure!

This is where we, as a group, teach common sense.....

Let's look at absolutes vs varied values-

Hooking up amp(s)-

They MUST be wired and grounded- Absolute

They use a minimum suggested power source with good results - Varied

They draw power - Absolute

Their power draw varies RAPIDLY - Varied results

Now for more precise examples-

Stock electrical -

100A alt, stock 60aH batt.

Amp install- 2,500w total

The amp will draw more power than without it being installed - Absolute

The amp will work regardless if using stock or upgraded electrical system - Varied

The amp will NOT be harmed under proper monitoring and control of electrical system due to poor or stock electrical system - Absolute!

So what is the reason for upgraded electrical system vs stock?

The answer is VERY simple! This is why i will repeat this-

STOP PUTTING YOUR ELECTRICAL SYSTEM UP ON A PEDESTAL!

The less capable an electrical system is... the more the voltage will drop. I'm hoping everyone knows this...

(i'm not going to get into the technical details of why higher voltage is better, it's just a given. but stressing over achieving certain high voltage numbers is just stupid for daily driving..)

The question is.. what is YOUR threshold? There is no set voltage that everybody says, yea that's my threshold...

All you need is a DMM.. that's it.. little few dollar device is all you need.

I recommend upgrading electrical system AFTER testing your new install.... not before...

IF you do it before, you will probably be wasting money because you do not know exactly what you need\want.

Common sense does come into play here...

You can't install 3,000w on stock system and jam on it forever without checking things periodically... If you do not understand that statement as to why... you have more to learn before installing batts\alts yourself.

So, this is what i recommend..

Install all your stuff... Purchase the LEAST amount of batt that would be ideal to get it functioning and test with dmm to measure voltage drop to determine if u need more batts or more alts.

I'll give you an example-

I ran 21,000w worth of amps on stock 100A alt, stock battery, 1 D3100 and 1 D5100 for 3 months.

I ran demos on and off consecutively for about 45 min.

I constantly checked voltage levels and current output from stock alternator EVERY FEW MINUTES while i was in park. If i were driving and had it cranked, these levels would be checked TWICE A DAY when in park.

You gotta use your head and make sure that things are not being stressed.

Am i recommending someone do as i did? NO NO NO.

That is an example.

It is to prove a point.. If you are new to the upgrade your electrical system game.. then sure, u can do that and see how much voltage drop you get the more you crank it up. Start off at low volume obviously and work your way up.

How to tell if u need more batts or more alts?

Assuming you are testing this at the given rpm value you wish to have good voltage, then continue-

Most AGM batts top out fully charged at 13.0-13.1v

when your car is above 13-13.1v, your alternator is in control.

If the voltage ever drops to 13-13.1v, your alt is maxed out it's output at that particular rpm value.

If you want higher voltage, u need better or more alts...

Is it necessary? Hell no!

If your voltage drop is dropping below 13-13.1v, your batt(s) either need charging immediately or you just do not have enough batt power to efficiently keep up with the current demand.

Is it necessary to get more in that case? Hell no!

Everyone's opinion varies because it's personal preference.

Here is my preference for daily driving-

I do not EVER want to see voltage drop below 12.0v on the hardest bass note possible! IF it does, you NEED more batts(or alts if u got the room for them. Remember, below 13v.. your alt is maxed out)...

If voltage drops below 12.0v.. you are discharging your batts quicker than i would recommend and will take longer to charge them up and continuous use like this WILL result in the shortening of it's suggested life span.

The lower the discharge and discharge state before a recharge, the longer a batt will last... Period!

So what did we get from this?

Use minimum electrical system with a bit of common sense to back it up.

Use DMM to periodically test maximum voltage drop and base your upgrades off of that.

Do NOT be stupid and use too low of an electrical system on a gigantic install power-wise.

Use your volume knob if you are unsure of what your current electrical system can provide..

Remember, keep gradually turning it up another couple notches and measure voltage drop until u reach the max volume you wish to listen to it at(example of how to do it).

this will save you money on overkill of buying batts and the questions on if u have enough....

If you any questions about what minimum electrical system will suffice.. READ THIS AGAIN until u hate car audio. If you do not know.. you are not comprehending....

At volume 1, it will not pull the same power as it will at volume 30 and so on...

ANY electrical system can support an install... It's just at what volume level?

Happy testing.. i hope..

I hope many of you grasp this as it's not hard at all...

[shizzzon 461]

I do need to add onto this though as i feel i left a gaping hole in this rant...

If your voltage is ALWAYS dropping to 13v or lower or even worse, stays there during jammin.. STOP DOING THAT.

The alternator can get killed by doing that.

this is what i would do in this case-

go buy a True RMS Ammeter.

Set car at idle(park), blast it for a few seconds and record maximum current out at idle from alternator.

This is a number u never wish to see again

If u feel u do not have enough alt power.. periodically check current output levels when in park to make sure your alt is not maxed out in park when stereo is off.

this is too ensure that the alt is not being overworked to maintain batteries.

Again.. if voltage is always dropping to 13v or lower.. I WOULD recommend either upgrading alt or turn the volume DOWN.. alt failure can and will happen eventually... if prolonged

[bassahaulic 155]

I feel it is needed that it is mentioned that my 3,000w and your 3,000w may be two different beasts altogether.

I run my two db Drive 1,500's at .4ohm each daily, and get drops into the 12's. When I ran a D9 at .8ohm it never went below 13.2 but was louder. Amperage draw is more then just the power you make.

[shizzzon 461]

Exactly my point-

I am tired of people looking at WATTAGE values and trying to base their new electrical system off of that....

With a dmm, u can see what type of voltage drop a user is getting...

[onebadmonte 235]

Nice read. Reminds me of when people ask how big of a fuse do they need for X amp. The answer is in the wire.

[Adrian_D 520]

I feel it is needed that it is mentioned that my 3,000w and your 3,000w may be two different beasts altogether.

I run my two db Drive 1,500's at .4ohm each daily, and get drops into the 12's. When I ran a D9 at .8ohm it never went below 13.2 but was louder. Amperage draw is more then just the power you make.

Apart from efficiency there is nothing else. You draw power to make power.

[///M5 2,833]

Dude, wtf. If you are trying to make a point perhaps you should re-read what you type. This is far from the "End All" thread and just furthers my opinion of you.

[emh9009 199]

Why so many ellipses?

[shizzzon 461]

i didnt have time to reread what i typed. i was having a headache.. hence the rant..

[Godsmack 360]

Dude, wtf. If you are trying to make a point perhaps you should re-read what you type. This is far from the "End All" thread and just furthers my opinion of you.

Well put.

i didnt have time to reread what i typed. i was having a headache.. hence the rant..

Well now ya do. Hop to bro.

J