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do i need a high powered alt.


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still_walkin 
Silver - Posts: 644
Silver spacespace
Joined: April18, 2007
Location: California, United States
Posted: November05, 2012 at 9:15 PM / IP Logged  
Their you go so I'm saying you can design a system and not use a cap and a hi output can power the system without a cap;)
1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August08, 2012
Posted: November05, 2012 at 9:32 PM / IP Logged  
You didn't say you were going to use a Red Top battery! And a Cap is cheaper than replacing a good battery. If look is more important then cost then yes. Logically a Cap is the first step in upgrades of a system. Then alt and battery to alt wire. Then an aditional battery. FYI no audio pro would ever put together a system with out a Cap, even with all digital amps and Red Top batteries.
still_walkin 
Silver - Posts: 644
Silver spacespace
Joined: April18, 2007
Location: California, United States
Posted: November05, 2012 at 9:38 PM / IP Logged  
Now we are going off topic who doesn't add a bunch of electronic upgrades and not put a good battery under the hood. Look at all these cool things I have but it doesn't start. The very first thing you do when u start modifying the car with abunch of electronics is to beef up your charging system. The purpose of this thread in question could I get away without beefing it up and based on the amp I picked I cant so time to put in the zero gauge;)
1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August08, 2012
Posted: November05, 2012 at 10:31 PM / IP Logged  
still_walkin wrote:
Now we are going off topic who doesn't add a bunch of electronic upgrades and not put a good battery under the hood. Look at all these cool things I have but it doesn't start. The very first thing you do when u start modifying the car with abunch of electronics is to beef up your charging system. The purpose of this thread in question could I get away without beefing it up and based on the amp I picked I cant so time to put in the zero gauge;)
Most DIYers don't and only you know how you will use the system which will determine the load on the system, do you listen to it loud with lots of BASS regular then yes upgrade is recomended, listen not so loud with no sub(s) upgrade probally not needed. If your combined amp's of draw dosen't exceed the output of the alt and voltage is above 12.5v to keep the battery from being discharged, then upgrade proably not needed. You can guess all that you want but until you install it and see it just a educated guess. As for the Big 3 for 1 Amp is not needed. If you do the Alt upgrade then alt to battery feed (4 ga)is recomended. Muliple amps (sub) then all three.
oldspark 
Gold - Posts: 4,913
Gold spacespace
Joined: November03, 2008
Location: Australia
Posted: November05, 2012 at 10:36 PM / IP Logged  
Sorry guys, I just returned.
I intended to replace my reply asking about the "10% extra" with a more direct reply...
The 10% means an upgrade may not be required.
VIZ - that 10% overhead is for a vehicle idling in peak-hour traffic in the cold dark rain. Hence the alternator outputs sufficiently - plus 10% reserve - at near idle speeds with headlights on, wipers on slow, heater fan and rear demister on, and normal audio, stop lights and indicators. And it will still recharge the battery after several short stops and longer than usual cranking times on an old battery.
Ergo, headlights & wipers & demister off and you have an extra 30A available.
Increase from idle speed and you have even more available.
Assume the 700W RMS amp is at 1/4 volume hence maybe 500W input. That's under 50A which the system may well handle.
My point is that I often see those types of "10% extra" or "minimum additional cost" statements. But 10% extra to what? [And if they theoretically needed a 67A alternator, they wouldn't build it, they'd get the next existing size (maybe 75A) or maybe a 90A or 120A alternator if they are cheaper (thru mass production, or with fitting and bracket costs etc).]    
As I see it, manufacturer's do not want vehicles to fail in the rainy dark cold peak-hour scenario I mentioned, so that is their baseline - NOT the "normal" daily cruise scenario.
How best to design? Well apart from being prepared to add the extra amp/load requirement (at 100% power all the time, or 25% half the time, etc?), it's by observation.
IOW a voltmeter. And preferably before the addition so you get familiar with how often the alternator is under-voltage yet the battery reliably cranks next time, or the battery is fully charged by the journey's end.
(Refer elsewhere to 12.7V and under being battery discharge, up to 14.4V being a normal charge, and over 14.4V long-term leading to battery destruction.)
Some have upgraded from 45A alternators to 200A alternators only to be worse off. (IE - many OEM alternators output more current at lowish RPM than do high-output alternators.)
And they only found out when their vehicle failed to crank later...
Now, if they had a voltmeter...!
As to later posts, forget caps. They do nothing to increase the power output of alternators - they can only store charge. And that charge is far exceeded by a battery. (Even a 1.2AH battery holds more charge than a BIG multi-Farad capacitor.)
In general, the only use for a cap is in BIG audio systems (2-3kW and above) where adjacent AGM batteries are used, and that's ONLY to protect the AGM battery (ie, take off some of its surge requirements).
When caps are used for filtering, a battery is generally far superior, plus the battery has the advantage of a much larger capacity for better sag ride-thru.
If the extra battery (instead of the cap) is 7AH or 15AH or larger, it can be an emergency cranker. How many caps can do that?
Of course a 2nd battery must have some form of isolation when not in use. That might be an automated system (alternator controlled relay aka "the UIBI", or a voltage sensing or "smart" isolator), or even an IGN or switch controlled relay, or mechanical links.
Only when that is not practical or possible might a cap be considered - eg, a cap across headlights to minimise dips - but then a faulty cap will act the same as a faulty parallel battery.
As to caps or batteries and alternator loading, forget it.
Some say they reduce alternator loading though probably most say they increase alternator loading.
In fact the former is the truest (extra or bigger caps & batteries REDUCE the demands on the alternator), but it should be irrelevant anyhow since alternators are self-limiting wrt to output current, and only poor designs will fail under normal situations (including jump starts!).
If audio buffs reckon they increase loading, then they should logically support having smaller batteries, and of course never an AGM!
Of course they might only argue against a cap since they have no charge-current limit per se whereas batteries will have a limit (even if it exceeds their specification).
But audio buffs that are in to (peak) SPL competitions will usually tell you NOT to have a cap, and similarly not to use AGMs, or not electrically adjacent AGMs).
The other advantage of the voltmeter - your super-duper alternator has worn brushes and is dropping output. You'll know about it before it's too late. (It will also pre-alert you to a failing battery.)
There are lots of other considerations like do you need peak voltage (14.2-14.4V) or how often do you want the battery to discharge and recharge - and to what level.
I have only skimmed some basics.
Oh - and BTW - the BIG-3!
still_walkin 
Silver - Posts: 644
Silver spacespace
Joined: April18, 2007
Location: California, United States
Posted: November05, 2012 at 10:37 PM / IP Logged  
I listen to my music balanced the bass his and mids all balanced. As for the 4 gauge upgrade that was a no brainer that is what I ment by beefing up the charging system. But numbers are numbers and for me to blindly ignore specs install something that's gonna give me problems later on nope . I rather do it right the first time and move on to the next project. Thanks for your help I figured out how I'm gonna do this install .as for olds spark you hit it right on the button caps vs hi out puts. I WL be running the amp when the car is on or in acc but I saw some direct bolt alts online but I'm going to visit my local guy that does all my alts and see what he can do for me .
1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"
still_walkin 
Silver - Posts: 644
Silver spacespace
Joined: April18, 2007
Location: California, United States
Posted: November05, 2012 at 11:45 PM / IP Logged  
So oldspark what's your decision would you go with a smaller amp because the factory front is 4x10 and rear is 5x7 and a free air sub for the back I'm not looking for booming just basic sound
1993 sdv
Alpine 4x6 6x9 5 1/4 swr-10d4
alpine v60
12.5 VGA flip down
Nettop pc w/10" touch screen
78nova
5-re audio 5x7 ,10" sub &
Xtx-500.5
"Take the faceplate off get the jumperpack"
oldspark 
Gold - Posts: 4,913
Gold spacespace
Joined: November03, 2008
Location: Australia
Posted: November05, 2012 at 11:59 PM / IP Logged  
Yeah, it sounds like you're on the button.
As to caps, I think you know this site's arguments - as well as Richard Clark's views. (It amuses me when someone can't kill the falsity they started. Yes, that's a personal experience too LOL!)
As to AGMs, I'll avoid Optima discussions (just seach).
But my usual argument is if only using a single battery in the engine bay, then stick the original type - ie, flooded if it's a wet/flooded type.
As to swapping to an AGM for audio reasons and hence often destroying the main/cranking battery quicker whilst gaining little for the audio, if people thins it's worth that to gain a few milli-Ohms when the distribution to the amps is of similar or higher resistance...
We solve that with the Big-3 instead.
Only then we might consider an AGM if needed, but that would almost certainly be a "remote" AGM, ie adjacent to the amp. And that's usually a second battery so that we have cranking independence. (The longer starter-motor cable run means cranking is less damaging to the engine-bay mounted AGM.)
As to caps being cheaper. I have yet to see a multi-Farad cap that is cheaper than a 1.2AH 12V AGM battery. Again, not that that matters because of the cap's inferiority (read: uselessness in comparison to a battery for most situations).
Incidentally, do they have those pocket sized emergency starting batteries over there? Usually nothing more than a 1.2AH or ~2AH 12V AGM except for their inline charger.
And as I've posted, stick to an S-type alternator (ie, 2 wire).
Apart from charging based on the actual battery voltage as well as being able to easily increase the charging voltage if needed (eg, using diodes), you can base the charging voltage on the remote battery if desired - and then "chop" the output to the front battery if needed. Oops - I have yet again destroyed the livelihood of a few local self-interests.
If you try with your existing alternator before changing over, keep in mind that only a few minutes at reasonable RPM is enough to adequately recharge most batteries sufficiently (assuming the normal "no more than 20% discharge" for a cranking battery).
So hence maybe a final run with low amp volume if the system has been below its normal voltage - ie, normal being above 13.8V and usually ~14.2V.
If it is (say) 14.0 to 14.4V, it is charging the battery at its required rate.
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August08, 2012
Posted: November06, 2012 at 12:25 AM / IP Logged  
Well to jump start a vehicle with the newer gm alternators while running greatly increases the likely hood that the regulator or rectifier in the alt will get damaged. As they don't like spikes and all new or remanufactured specificly say to fully charge the battery before installing the replacement or regulator damage will occur. I had to replace 2 of them so far one because she let the vehilce set for a couple of months and the jumped in and started it and a few minutes later the light charge light came on. The other jump started someone and the charge light came on a few miles later on his way home both vehicles had under or around 60,000 original miles when this occured. In both cases the rectifier was shot, replaced the rectifier and alt's tested good and have been running ever since. And standing voltage on flooded lead acid batteries is around 12.5 volts, and 12.7 for optima AGM here in the US. And the 12.7 was right from Optima tech support dept.
This was over 2 years ago and they haven't had a problem since so everyones opinion is subjective to their experiences. I have ran a Directed 1100D ISACA Certified Edition (4 ga direct to amp terminal, 1100wats @ 1 ohm, pulls up to 90 Amps)on a stock 105 amp cs-130 alt with a Diehard battery and a 1 farad cap for 5 years now and the alt and battery are still going strong. So take it anyway you like but there is more than 1 way to do things, oh and none of the Big 3 were done either. Thought about up grading the alt wire to battery but haven't done it yet.
Optima batteries here are $180 and up in the US, 1-Farad caps are $100 for a monitor top less for a non-monitor. Thats for brand name Caps there are cheaper ones than that from off brand companies.
oldspark 
Gold - Posts: 4,913
Gold spacespace
Joined: November03, 2008
Location: Australia
Posted: November06, 2012 at 3:04 AM / IP Logged  
Geez I keep missing these replies...
Still_walkin - I'm no amp nor speaker expert so that's a question for others. But IMO a bigger amp might be better provided it can still output well at lower volumes, and provided it isn't up high enough to blow the speakers. But gain adjustments should solve both issues.
And if it's too big for the alternator, turn it down until you get a copious alternator. (Overnight charging is an option, but that means the battery is being overly labored etc.)
Lurch - you have supported my argument(s) well.
Jumping etc won't blow regulators (that would be a really crap design!).
And what I consider poorly designed alternators can blow after starting on flat batteries. I had such experiences with Bosch alternators before returning to my typical albeit newer Jap alternators. It sounds like the GMs (Delphi?) are like Bosch. You have my commiserations.
My Bosch experience made me realise that the spouse's tale about keeping the jumper battery connected for a while after starting was not in fact a bullsh myth. (I was almost made an honorary Myth Busters member LOL!)
But that is due to underrated main diodes which IMO is pathetic. Surely one should be able to roll start a vehicle without blowing the alternator? After all, if the windings and current output is self-limiting....
But the above aren't spikes - they are longer overloads. Only lightning are some welding spikes should be able to kill alternator diodes - and that's from reverse biasing (above their PIV rating).
As to the Optima tech guys, I suggest they get some proper battery literature and read their own sales brochures.
12V lead-acid Batteries are ~12.7V fully charged (12.67V @ 25C) though Optima often claim higher for their batteries, as well as a charging voltage higher than the normal maximum of 14.4V.
Thanks too for the pricing. 1.2AH batteries here are ~$15 and 7AH are ~$25-$30. Despite your cheaper prices, the battery still wins.
If you can show me the different behavior with and without the cap connected in your system I'd be obliged.
Mind you, I'd usually compare that to a system with a much cheaper 1.2AH or larger battery in the cap's place. You seem to be running a single battery so a cap is more likely to have a beneficial effect as opposed to common audio boot/trunk battery set-ups, but the cap is still not as good as a battery in lieu.   
I feel it's a pity you didn't upgrade the big 3 - that is an area where manufactures can minimise costs, and it could have saved you the cost of the cap.   
To increase vehicle electrical loads without increasing ground cable ratings is also risking expensive damage to the loads and vehicle.
But maybe the voltage across your amp at 90A is not significantly different to the front battery's voltage.
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