Alternator Question

[Bmwz389]

I'm puttin in a new sub system in my 92 xlt, and Im putting in a Spare Optima YellowTop Battery.

But I read up on other places and they said I would need a battery Isolator to keep the other battery from draining or sumthin.

And then someone said somthin about how since I'm having 2 batterys and a system thats pushin a kicker kx1200.1, I would need a bigger alternator or sumthin. But I have no clue what to do there because I thought all I would need was another battery...

So whats my stock alternator cca? can it push my new system with 2 batteries?

Anything guys/girls? Thanks!

 

[Jason94sport]

The alternator charges the battery when the engine is on. A stock 92XLT one is 90 amps. You have alot of power drain on the stock setup. Adding a 2nd battery will tax the system even more since you now have 2 batteries to charge. A higher amp alt would help a great deal. You don't need it though. I'd say do your install, & see afterwards if you have power drain problems.
And you do need an isolator for the 2 batteries.
You really don't need a 2nd battery either. A higher amp alt will do the job. Unless you want to play your system all day with the engine off.

 

[aldive]

I would upgrade the alternator.

Good luck ........

 

[BBQ_HotDogs]

Get a 200 amp alternator from www.mralternator.com they are reasonably priced and work great. You do need an isolator though. If you do not know what you are doing, maybe let a professional help you out.

 

[Wagonized]

id get a good high output alt 160+ amp and ditch the second battery

 

[DOZIER]

what is an isolator?

 

[Wagonized]

what is an isolator?

http://www.bcae1.com/battiso.htm

 

[CDW6212R]

The second battery would be helpful for engine off use, or really high end audio power sourcing.
You don't have to have another alternator if you don't have a huge extra load, say over an extra 30-40 amps.
The later 90's alternators are better, even the same amperage rated versions. I have a 130 amp stock 2000 alternator in my 91. It holds 14.4volts at all settings, everything off, or everything on.

If you really have to have something beyond the 130 amp stock units, look on Ebay for DB Electronics. They have a brand new 170 amp alternator for about $140. They also have a rebuilt 200 amp alternator for under $200. Good luck,

 

[FexplorerV8]

u dont need a new alternator or an isolater UNLESS u wanna run the radio with the car off, i have a 96 V8 with 2 batteries *regular* batteries none of that yellow top high spending nonsense and it works like a champ, i'v had it installed for about a year now.

 

[Wagonized]

u dont need a new alternator or an isolater UNLESS u wanna run the radio with the car off, i have a 96 V8 with 2 batteries *regular* batteries none of that yellow top high spending nonsense and it works like a champ, i'v had it installed for about a year now.

the problem with that is the 2nd battery puts farther strain on your stock weak alt as it has to charge a second battery now aswell.

in fact most people add a 2nd battery for playing with the car off and add a higher output alt for playing with the car on

 

[FexplorerV8]

not it u have a system like mine, before i had the 2 batteries even with the car on i couldnt turn it up that much because the volts would drop like crazy at night the head lights would dimm so much the battery light would go on.... i talked to a lot of people about getting yellow top red top all kinds of batteries did a lot of research though of a new batterie but the fact is the alternator used in the explorer its capable of charging the 2 batteries without doing any harm. i have a friend that did the same thing in a honda civic lmfao have u seen the alternator in those things?! is like 30 or 35 amps and he just loves the set up, his has been running strong for about 8 months
Everything works great on my truck it turns on easier my lights dont dimm and i can turn up my system all i want even with it putting out its max.... it works great!
if u wanna spend a lot of money... hey go for it, all i know is that i had this thing set up for less that 40 bucks, because i have a friend that works at discount auto parts and he had some batteries that had been returned because they didnt fit the cars ppl bought them for, sold me one of em for like 25 bucks and its still working fine after a year
look at my cardomain pics... judge urself

 

[Wagonized]

not it u have a system like mine, before i had the 2 batteries even with the car on i couldnt turn it up that much because the volts would drop like crazy at night the head lights would dimm so much the battery light would go on.... i talked to a lot of people about getting yellow top red top all kinds of batteries did a lot of research though of a new batterie but the fact is the alternator used in the explorer its capable of charging the 2 batteries without doing any harm. i have a friend that did the same thing in a honda civic lmfao have u seen the alternator in those things?! is like 30 or 35 amps and he just loves the set up, his has been running strong for about 8 months
Everything works great on my truck it turns on easier my lights dont dimm and i can turn up my system all i want even with it putting out its max.... it works great!
if u wanna spend a lot of money... hey go for it, all i know is that i had this thing set up for less that 40 bucks, because i have a friend that works at discount auto parts and he had some batteries that had been returned because they didnt fit the cars ppl bought them for, sold me one of em for like 25 bucks and its still working fine after a year
look at my cardomain pics... judge urself

the 2nd battery is working as more of a buffer for when your current draw exceeds the output of your alternator.

I dont doubt that it works, hell ive even done it before. Its just not the proper solution as you'll end up spending money twice once your alt craps out early.

 

[CDW6212R]

The alternator should be sized based on the extra load. Newer 90-130 amp alternators are massive, compared to 55-70 amp alternators before the 80's. The accessories have not doubled in a stock vehicle. The factory(any size) alternator can charge several batteries.

Example: My first car, a 1972 Gran Torino, with a 55 amp alternator, a 20-30 amp load Nakamichi amplifier(PA200), and four 100 watt headlights. The alternator was fine with the stereo, and then when I changed the bulbs I had dimming. I had to add a relay solenoid to power the headlights, and the lights were still dim on high beam. I had the alternator checked. It was only making 40 amps max, and I had it rebuilt into an 80 amp unit. After that, my stereo and headlights worked flawlessly. I added over 50 amps extra load, and an 80 amp alternator did very well.

The only factor to consider is the extra loads over the stock system. A single battery is less of a draw than any small amplifier. Add up the amperage of all extra components. Only when you start adding over about 30-40 amps should you consider a bigger alternator.

 

[TeamPwnageBrad]

not it u have a system like mine, before i had the 2 batteries even with the car on i couldnt turn it up that much because the volts would drop like crazy at night the head lights would dimm so much the battery light would go on.... i talked to a lot of people about getting yellow top red top all kinds of batteries did a lot of research though of a new batterie but the fact is the alternator used in the explorer its capable of charging the 2 batteries without doing any harm. i have a friend that did the same thing in a honda civic lmfao have u seen the alternator in those things?! is like 30 or 35 amps and he just loves the set up, his has been running strong for about 8 months
Everything works great on my truck it turns on easier my lights dont dimm and i can turn up my system all i want even with it putting out its max.... it works great!
if u wanna spend a lot of money... hey go for it, all i know is that i had this thing set up for less that 40 bucks, because i have a friend that works at discount auto parts and he had some batteries that had been returned because they didnt fit the cars ppl bought them for, sold me one of em for like 25 bucks and its still working fine after a year
look at my cardomain pics... judge urself

What if your battery should tip over somehow and spills? that will not happen with an optima or some other sealed deep cycle battery. What about the fumes that can be produced as well?

 

[Wagonized]

. Only when you start adding over about 30-40 amps should you consider a bigger alternator.

the thing is any decent sub amp out there will be pulling way more amperage than 30-40 amps. The alt is the high commander of your electrical system without a good base the rest will be crap

 

[CDW6212R]

Well, see, you are talking about big amps. I did not read any mention of big amps previously in this thread. A second battery is a drop of water in an ocean compared to amps which pull over 40 amps.

I did not make an assumption, I made a recommendation that could apply to anyone. If 40+ amps is needed, then clearly a stock alternator would be pushed to and beyond its limits at times. Regards,

 

[Wagonized]

Well, see, you are talking about big amps. I did not read any mention of big amps previously in this thread. A second battery is a drop of water in an ocean compared to amps which pull over 40 amps.

I did not make an assumption, I made a recommendation that could apply to anyone. If 40+ amps is needed, then clearly a stock alternator would be pushed to and beyond its limits at times. Regards,

actually you'd be surprised.

my stock alt is running my stereo right now and its about 250 amps max current draw. Dips down to 10.9ish volts on hard long bass hits and stalls the truck occasionally but its still alive.

Planning on putting in my 280 amp GM alt this week

 

[Jason94sport]

I have a 250W amp that pulls 40amps. I have a 100W spotlight that pulls 20, plus flasers that pull 5. 65amps. My lights would dim at night & my AC would get slow unless I had my foot on the gas. I installed a 200amp alt & a red top & all is well. I can run everything & sit idle & volts at the battery do not dip below 14.

 

[BBQMAN]

I had a JL 1000/1 driving 2 12W6V2's, a JL 300/4, & a JL 300/2 in my 98 5.0L with stock battery and stock alt. I did have a 1 farad cap though, never had a problem in the 3 1/2 years it was in there (I traded in the truck last week on a '05 4.6L)