Capacitors

[bubbagumper6 5,000+ posts]

Exactly, if you have a huge battery bank it may seem like your electrical is up to par but you'll be putting a ton of stress on your alternator and probably cause it to fail prematurely.

 

[VWBobby 10+ year member]

They see me trollin, they're hatin.... I'll take the bait. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

A battery bank can be a band-aid fix for an improper charging system. Here's how:

1) Nobody draws 100% full power, 90% of the time. If you were to build a "burp machine" that was only good for full RMS power on test tones, and shut off the engine, never allowing the batteries to charge back up - this *would* be an exception. However, when you are done running a burp, you can leave the vehicle running to charge your battery bank back up. Depending on how far the bank is drained, and what capacity alternator you have, is how long the engine will need to be left running.

2) On the quiet/silent parts of the music, the system may be drawing as little as 10% of your reserve capacity. This means, on a 100A charging system, with an idle draw of 40amps, you still have 54 amps available to charge the battery (60 minus 10% = 54).

3) Alternators differ from generators in the fact that they take AC power and rectify it to DC. If the battery(s) is still in good condition then it will accept a charge. A "bad" battery will have a greatly reduced capacity and won't be able to hold a charge under these conditions, no matter how many amps you throw at it. Generally a battery must be sulfated, corroded or leaking in order for it to lose its capacity.

4) Most "burp machines" that are not used for daily driving, have 1 regular or high capacity alternator. The owner will charge up the battery bank with a typical 100-250 amp quick charger before each comp. If the comp rules allow for the engine to be running, this will give the competitor an edge having high operating voltage during their run. Otherwise you can still "cheat" by using a 16 volt system, with the engine off, if the rules allow.

I always get a laugh out of the guys with the 4-5 high output alternators.... What's the point? You would have to be burping at full capacity and shutting your car off afterwards, without letting your batteries charge back up. I don't know too many people who run their cars just to bass, then turn them right back off again.

A 100 amp alternator can charge several drained batteries just as well as a bank of alternators putting out 1000 amps. It will just take 10 times longer to charge. Its not like the alternator will burn itself up by putting out full capacity. That's what the rectifier and voltage regulator circuitry is for. It will just be running at full duty cycle until the battery bank is charged back up to capacity. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif The only time I have seen a damaged alternator was due to improper grounds, reversed polarity, or overheating (from the engine).

(puts on flame proof suit and ducks for cover)

 

[Buck 5,000+ posts]

I just need a bigger alty to charge quicker, and more at idle.

 

[nevertoomuchbas 10+ year member]

Okay im a little confused now. I knew caps were basically useless, But I just invested in a $120 deka 8a31 as a secondary battery. Ive got a mmats 3000.1 and it was just too much on my starting battery. when it would hit hard my voltage meter would just take a dive. I would have gotten a h/o alt, but i dont have that kind of money right now. So will this battery actually not do much of anything for me?

 

[pimpnyou204 10+ year member]

Really I kind of don't see the point of this.. A capacitor on paper is a much better battery bcuz it delivers a stronger voltage and faster but a battery is longer lasting and if u ride in a daily car with a stock alt you won't get far so all were proving is they all work together.

Personally what I would think is cooler is if they could figure out or create a device to give a digital read out of the amps your charging at and how long continuing at this limit on said bass line (song) u would have until u drain your batteries or cause a car to shut off from such a voltage drop. Bcuz their making this for all the ppl who don't buy ho alts brag about their 3k watts and 3 15s etc and have completely stock electrical and never plan to change it.

Anybody who's anybody knows u need both in combination and if u could match your alts to your amps used a nice big cap would do well on those big bass hits bcuz it delivers a stronger faster signal. But we all know paper never relates to real life.

 

[ahole-ic]

They see me trollin, they're hatin.... I'll take the bait. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gifA battery bank can be a band-aid fix for an improper charging system. Here's how:

1) Nobody draws 100% full power, 90% of the time. If you were to build a "burp machine" that was only good for full RMS power on test tones, and shut off the engine, never allowing the batteries to charge back up - this *would* be an exception. However, when you are done running a burp, you can leave the vehicle running to charge your battery bank back up. Depending on how far the bank is drained, and what capacity alternator you have, is how long the engine will need to be left running.

2) On the quiet/silent parts of the music, the system may be drawing as little as 10% of your reserve capacity. This means, on a 100A charging system, with an idle draw of 40amps, you still have 54 amps available to charge the battery (60 minus 10% = 54).

3) Alternators differ from generators in the fact that they take AC power and rectify it to DC. If the battery(s) is still in good condition then it will accept a charge. A "bad" battery will have a greatly reduced capacity and won't be able to hold a charge under these conditions, no matter how many amps you throw at it. Generally a battery must be sulfated, corroded or leaking in order for it to lose its capacity.

4) Most "burp machines" that are not used for daily driving, have 1 regular or high capacity alternator. The owner will charge up the battery bank with a typical 100-250 amp quick charger before each comp. If the comp rules allow for the engine to be running, this will give the competitor an edge having high operating voltage during their run. Otherwise you can still "cheat" by using a 16 volt system, with the engine off, if the rules allow.

I always get a laugh out of the guys with the 4-5 high output alternators.... What's the point? You would have to be burping at full capacity and shutting your car off afterwards, without letting your batteries charge back up. I don't know too many people who run their cars just to bass, then turn them right back off again.

A 100 amp alternator can charge several drained batteries just as well as a bank of alternators putting out 1000 amps. It will just take 10 times longer to charge. Its not like the alternator will burn itself up by putting out full capacity. That's what the rectifier and voltage regulator circuitry is for. It will just be running at full duty cycle until the battery bank is charged back up to capacity. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif The only time I have seen a damaged alternator was due to improper grounds, reversed polarity, or overheating (from the engine).

(puts on flame proof suit and ducks for cover)

You're not wrong in what you say, but that doesn't contradict with the original post, nor is it applicable to the target audience.

 

---------- Post added at 07:28 AM ---------- Previous post was at 07:27 AM ----------

 

Okay im a little confused now. I knew caps were basically useless, But I just invested in a $120 deka 8a31 as a secondary battery. Ive got a mmats 3000.1 and it was just too much on my starting battery. when it would hit hard my voltage meter would just take a dive. I would have gotten a h/o alt, but i dont have that kind of money right now. So will this battery actually not do much of anything for me?

It can ONLY help keep your voltage above 12v for a little longer.

 

[i2ain2thunder 10+ year member]

Really I kind of don't see the point of this.. A capacitor on paper is a much better battery bcuz it delivers a stronger voltage and faster but a battery is longer lasting and if u ride in a daily car with a stock alt you won't get far so all were proving is they all work together.
Personally what I would think is cooler is if they could figure out or create a device to give a digital read out of the amps your charging at and how long continuing at this limit on said bass line (song) u would have until u drain your batteries or cause a car to shut off from such a voltage drop. Bcuz their making this for all the ppl who don't buy ho alts brag about their 3k watts and 3 15s etc and have completely stock electrical and never plan to change it.

Anybody who's anybody knows u need both in combination and if u could match your alts to your amps used a nice big cap would do well on those big bass hits bcuz it delivers a stronger faster signal. But we all know paper never relates to real life.

If the cap has a bank the same as a battery then its useful, I don't even know if one exists. Still here your sugessting that the faster signal matters, idk to me all that matters is the voltage thats what the amp uses. From the little I know about caps don't they start dropping in voltage immediately when discharging? or do they hold it untill fully discharged?

 

[bubbagumper6 5,000+ posts]

They see me trollin, they're hatin.... I'll take the bait. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gifA battery bank can be a band-aid fix for an improper charging system. Here's how:

1) Nobody draws 100% full power, 90% of the time. If you were to build a "burp machine" that was only good for full RMS power on test tones, and shut off the engine, never allowing the batteries to charge back up - this *would* be an exception. However, when you are done running a burp, you can leave the vehicle running to charge your battery bank back up. Depending on how far the bank is drained, and what capacity alternator you have, is how long the engine will need to be left running.

2) On the quiet/silent parts of the music, the system may be drawing as little as 10% of your reserve capacity. This means, on a 100A charging system, with an idle draw of 40amps, you still have 54 amps available to charge the battery (60 minus 10% = 54).

3) Alternators differ from generators in the fact that they take AC power and rectify it to DC. If the battery(s) is still in good condition then it will accept a charge. A "bad" battery will have a greatly reduced capacity and won't be able to hold a charge under these conditions, no matter how many amps you throw at it. Generally a battery must be sulfated, corroded or leaking in order for it to lose its capacity.

4) Most "burp machines" that are not used for daily driving, have 1 regular or high capacity alternator. The owner will charge up the battery bank with a typical 100-250 amp quick charger before each comp. If the comp rules allow for the engine to be running, this will give the competitor an edge having high operating voltage during their run. Otherwise you can still "cheat" by using a 16 volt system, with the engine off, if the rules allow.

I always get a laugh out of the guys with the 4-5 high output alternators.... What's the point? You would have to be burping at full capacity and shutting your car off afterwards, without letting your batteries charge back up. I don't know too many people who run their cars just to bass, then turn them right back off again.

A 100 amp alternator can charge several drained batteries just as well as a bank of alternators putting out 1000 amps. It will just take 10 times longer to charge. Its not like the alternator will burn itself up by putting out full capacity. That's what the rectifier and voltage regulator circuitry is for. It will just be running at full duty cycle until the battery bank is charged back up to capacity. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif The only time I have seen a damaged alternator was due to improper grounds, reversed polarity, or overheating (from the engine).

(puts on flame proof suit and ducks for cover)

I disagree completely with that last part. Clearly you've never taken apart a stock alternator after it's been abused...

 

[ahole-ic]

If the cap has a bank the same as a battery then its useful, I don't even know if one exists. Still here your sugessting that the faster signal matters, idk to me all that matters is the voltage thats what the amp uses. From the little I know about caps don't they start dropping in voltage immediately when discharging? or do they hold it untill fully discharged?

The voltage they hold is directly proportional to how much charge they had stored and rate of discharge. Since they don't hold much, and the rate of discharge is usually pretty hefty, they really don't have much for long. A really large capacitor bank would hold a larger charge, but at some point you have to ask yourself why? The ESR of each capacitor would make that not so attractive. Capacitors are just not very effective at these low voltages. If you had some higher voltage capacitors on the high voltage rails of the amplifier it would actually make for a much more efficient power supply design etc. That's actually what rockford did with the t15k. For what we are discussion though, capacitors aren't very effective... but they also don't hurt anything.

 

[i2ain2thunder 10+ year member]

The voltage they hold is directly proportional to how much charge they had stored and rate of discharge. Since they don't hold much, and the rate of discharge is usually pretty hefty, they really don't have much for long. A really large capacitor bank would hold a larger charge, but at some point you have to ask yourself why? The ESR of each capacitor would make that not so attractive. Capacitors are just not very effective at these low voltages. If you had some higher voltage capacitors on the high voltage rails of the amplifier it would actually make for a much more efficient power supply design etc. That's actually what rockford did with the t15k. For what we are discussion though, capacitors aren't very effective... but they also don't hurt anything.

Good to know yeah that was my understanding that they discharge quickly and have low storage therefore voltage drops too fast to even be considered more effective than a battery.

 

[pimpnyou204 10+ year member]

Just out of curiosity but from my understanding wouldn't ho alternators be the end all be all electrical component in everyone's car? Because as soon as u pull more amps than the alt can take your dropping to 12.7 when 14.4 is way more efficient and giving u more power. And the only way to keep a 14.4v is to match your alts amperage to the amps your drawing otherwise your gonna start to drop.

Like most ppl who have a big system (300a draw) on a stock alt (100a) you wont ever see what that 14.4 is bcuz you will drop as soon as u turn it up and rely on batteries. Please correct me if I'm wrong lol

 

[i2ain2thunder 10+ year member]

Yeah HO Alt is the most usefull thing you can get to help your voltage in that situation, however they are pricey and some of our broke butts have to get batteries and rely on them for a while. Hopefully you don't draw more than you can charge. All in all you need both a HO alt and good battery or batteries to maintain maximum voltage.

 

[pimpnyou204 10+ year member]

I think just about everyone draws more than they charge I mean think about it. Especially if your on stock.. U have to assume, depending on year of car your gonna use 40 amps on all your car electronics and even more in winter or night. With a moderate alt (100) you got about 60 amps left to play with and idk of many amps that draw that lil on full tilt and even a ho alt at 260 that's 220 left. And if I had to venture and guess I'd say the ppl who took the plunge on an ho alt are way past 220 amps bcuz 220 amp draw is what 2000-2800 watts? Split that between a highs and sub amp your taking it all.

Also a side question.. Is it true each battery u add gives u .2 more volts to your resting voltage?

 

[VWBobby 10+ year member]

I disagree completely with that last part. Clearly you've never taken apart a stock alternator after it's been abused...

I've taken apart several Bosch/Motorola and GM/Delco alternators. Only thing I've seen is blown rectifiers (diodes) and bad bearings.

Pimpnyou204, you got it. That's exactly what I was saying in my long winded post. Unless you're running several HO alts, everyone is exceeding their charging capacity at full tilt, and it doesn't hurt a thing as long as you let your batteries recharge. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Having a volt meter tied in near your amp(s) would be a good indicator if you are in danger of hurting your amp. As long as it doesn't drop below 12V, you really can't hurt anything. To measure current draw, the amp meter must be tied in-line with your power. This used to be popular in the up until the 80's when manufactures started deleting the amp meter from the cluster.

 

[pimpnyou204 10+ year member]

So most the time when ppl are giving 14.4v rms ratings it's pretty pointless bcuz unless you run a system of batteries on a set 16v system or whatever you really will only see those 14v till u turn it up and about a half minute after you'll be sitting on the batterieS resting voltage of 12.7v?