I would keep the stock alternator and add an additional alternator of as high an amperage at idle as will fit. I would budget $500 for that, and about $800 for batteries, as many of the newer style (kinetic, XS power, etc) as you can get with that money. With the remaining $200 I would get more 1/0 gauge and use multiple runs from front to back and also purchase some busbars for your battery bank. Obviously buy some fuses and fuse holders too.

Also, if you have an extra few bucks laying around a voltage meter is a good idea.

 

So what would be a good amperage output for the alternator?
Would I need to isolate the car elctrical from the stereo electrical?
What size fuses would I need?
The batteries wont be side by side. they are going to be stacked two high on each side - rear quarter panel fender spaces. So I wont be needing the busbars. I will have to do runs of 1/0 gauge.
How many runs of 1/0 do I need to run from the alternator to the batteries?

 

To answer your question the best I can:

Get as high an amperage as you can. If you can get 800 amps get that lol. But you want to find the highest amperage at low RPM because that's the most practical rpm range. It's not like you're going to be demoing with the car at redline for 5 minutes at a time.

The formula is amps X volts = watts. If you're actually pushing a REAL 10k, at 12.8v, (which is what your batteries should rest at with the car turned off) that means you'll draw ~781 amps. This is at 100% efficiency, and in the "real world" you're not even going to be 100% efficient.

If you really want to sustain this sort of power, your best bet is to put a couple more bucks into the setup and run dual 300 amp alternators, and that will allow you to play for a pretty long time before your battery bank is depleted. I would do two runs of 1/0 for power and two runs of 1/0 for ground (all from under the hood back to the rear batteries) Don't even bother with a chassis ground, just main line it.

(p.s. your charging system should run at 14.4v with no voltage drop so that means in reality you'll need ~694 amps)

 

To support 10k Kicker recommends two 200 amp alts and eight 800CCA batteries. I have been told that for each HO alt you need 3 to 4 batteries. Fusing is determined by wire size. The fuse is there to protect the wire from shorts. For 1/0 wire you need a 300 amp fuse within 18 inches from the power source. I myself am using four 200 amp alts with a custom alt bracket and eight deka intimidator 9a31 amg style batteries and just over 100ft of Radaflex 1/0 welding cable. I got a good deal on the alts, so so on the batteries and wire. It all tallies up to around $2500. Good luck.

 

I bought a 200A alternator from DbElectrical (I think they're out of Tennessee) for $215 shipped and I've had it installed for 3 years in a variety of high output installs with no issues. I never understood why guys spent $500-$600 on a single HO alternator, but to each his own. You could get two from Db for under $450 shipped, and that'd give you 400A. Find a dual alt bracket for your car, and spend the rest on batteries and wire. I live in Gilbert and should be able to get Kinetiks locally for wholesale still, so if you want to go that route I can get you some pricing so you're not paying shipping from somewhere. Batteries can get heavy. Speaking of which, you put 6-8 Kinetik batteries and 2 subs and amps in the trunk of a Cavalier, and that thing is gonna drag ass. Have you considered beefing up the rear suspension to support all this added weight?

 

does the $1500 cover the amps/gear too or just the electrical upgrades needed? Be sure to go with a sealed batter if you are mounting them in their side and will need multiple fuses and some way to mount them all down. Please don't tell me you are just hoping the weight of the batts will keep them from movin.

 

Figure your amp might be doing around 80% efficiency. So, to get 10kw out, you have to put 12,500 watts in. Now, wattage is voltage x current, as bd posted, so we divide 12,500w by 12.8v, we get 976.56 amps of current.
That's a lot of current.
Now, depending on how loud you play it, what you play, et cetera, you may well not be USING 10kw of power on a routine basis...but figure you'll need a lot of current. So, two alternators can help. As noted, get something that does a good bit of it's max power when you are at idle...this will cost more but gives more real world benefit. Know that a pair of alternators is NOT going to produce sufficient current to run 10kw...so at that point voltage WILL drop from 14.4 down to 12.8 (13.0 - 13.1 in the case of a handful of batteries). At this point if your batteries can take up the slack, it will stay there. If they cannot, it will continue to drop. Also note that batteries CANNOT shoulder any of the load until voltage drops to what they are sitting at. Until then, they are just weight and another load on the alternators.
Now- you find a pair of alternators, find a bracket for putting them in your car, note that you will lose some power off of the engine to run the second alternator.
Also keep in mind, the more you run it at levels above what your alternators can produce, the more battery you need to fill in the slack. BUT, as noted, batteries are heavy. Also...the more time the alternators are NOT providing sufficient power...the batteries are being drained...and if the batteries are draining...what is going to recharge them? You need to take these things into account as you plan the system. Having a grasp on WHY things will happen and WHY you are doing what you do, will help a lot more than "do this this and this" and just blindly following.

 

I am sendin out inquiries for pricing on the alternators tonight. I need suggestion on what batteries and links. I only can have four batteries in the trunk. about 11x8x8. they will be stacked two high on custom racks welded and bolted to the chasis. What should I put under the hood for a battery.

 

Are you going to do 12v or 16v? Look into Powermaster batteries & SPL alts
Northstar is a company that makes batteries for the Telecom world but you can use their NSB series (that's what it used to be called) batteries for your application.

 

Four isn't enough?
What's going to charge those batteries?

 

I bough bat cap 2000's and am now waiting on a quote on dual alternators

 

If you are only going to run 2 alts I would install one on these in back to where you just need to run an extention cord too and plug it in if you notice you batteries dragging.
Kinetik High Current Power Cells

 

I have installed two Batcap 2000's
I am waiting on two Excessive AMperage Alternators. 300amps.
I have 75 feet of 1/0 gauge Welding cable comming

I need...
connectors,
What fuse rating should I go with?
Where can I get those fuses and the holders.
Where or who makes disdtro blocks for all this.
I need a about 12?
I want to put in an isolator for the front battery. How. where?

 

People are going to stop answering your questions... Rather than asking them to what to buy... You should try to learn and understand every aspect of what you are trying to to. Let's say one day you decide you want to run a different setup... then what? You will be right back on here asking the same questions all over again. When dealing with this stuff you do not want to sell YOURSELF short or short your system. The reality of what you are asking people is just short of having someone else install it. I'm not knocking you, I'm trying to encourage you to actually learn this stuff. Ask questions but ask ones that will teach you not just ones that will give you a nutshell answer. I hope your build is a safe and gratifying one. Be safe and good luck.

 

isolator
good idea but if you can run the oem alt for your car electrical and keep the systems electrical separate
that way your car brain box or any other items will never see the surging effects from the amp draw

i run a nissan with a upgraded stock alt but the system is separate on two caddy northstar alts with battery bank.
i wired my alt>fuse(150A)> and again alt>fuse(150A)>boat battery switcher>fuse right before battery bank(300A)>amp fuse(350A) then to amp
the boat battery switcher is nice it has a 1 or 2 or 1 plus 2 or all off the idea is if one alt fails i can take it out of the system right a way and say you need the HP to get over a pass you can flip them off and keep all your HP to climb those hills .. system off of course. but this stuff no only adds a drag to your motor but also the weight
i know my system is a bit smaller scale but i think its important to think of all the options i prefer to leave my OEM stuff alone i dont want my system to be the reason im stranded someplace without cell service waiting forever.

 

I got most covered. Now I am waiting to contact toolmaker for some fuse blocks and others. if you want to check it out here is a link to my main forum I frequent...

Subzero's X3 10K cavalier rebuild..