Capacitors, their NOT what some people claim..

[BKNIGHTS 10+ year member]

A cycle is fully charging a cap and draining it. Which we are not doing in the car audio world.

I'm sorry but even the miraculous maxwell supercap will lose a percentage of their capacitive value over time, it would be correct to say it is still functioning but not the same as the time of installation.Perhaps Maxwell could explain to you how their 16V small cell module that's only rated for 1500 hours is somehow exceeding that figure, either you are wrong or Maxwell is wrong but i'm betting maxwell knows their product inside and out http://www.maxwell.com/products/ultracapacitors/docs/datasheet_16v_small_cell_module.pdf

Edit: A 1500 hour lifespan with 8 hours a day average listening time gives the cap just over 6 months to live, you may be right saying these systems have been in use for months, maybe 6 months at the most..

 

[big scott]

This is the equivalent of using Peel and seal roofing for deadening. Sure it works (sort of) temporarily, but its a huge mistake and waste of time/money in the long run.

you are right, like i said it works for me.

but like i said i will be changing it over to 2 audio battery's.

 

[gstokes]

Well that's a bit different than the one day figure you threw out before isn't it.

true, my apologies..

 

[gstokes]

A cycle is fully charging a cap and draining it. Which we are not doing in the car audio world.

this ^^^^, i did not take that into account.. But now i have even more unanswered questions, i don't understand how this technology works but i became a true believer after watching the video using the amplifier dyno, in the past they may have been a joke but times change and technology improves and makes a fool out of people like me, and i'm okay with that because it's a lesson i needed to learn.

 

[keep_hope_alive Premium Member]

I don't assume all caps are 1 farad, i just used a 1 farad cap as an example. The Maxwell ultracapacitor is a game changer but it's not a capacitor in the traditional sense, it's an electro-chemical device that mimics the characteristics of a high-value capacitor.

The 16V maxwell ultracap has a lifespan of less than half a million charge/discharge cycles, that's fine for regen braking and some other applications but in the life of the average car audio buff that would be about 1 day of listening to music and the cap would begin to fail so i don't think maxwell ultracaps would be a good choice for a car audio application.

the main difference between an ultracap and a standard electrolytic cap - the ultracap uses sheets of carbon which have 3,000 times more surface area than metal foil. that's pretty much it. they exploit the concept of capacitance being a function of surface area and distance. increase surface area and/or decrease distance and you increase capacitance. the carbon sheets just have a voltage limitation, hence the 2.7V rating.

the BCAP3000 is rated for 1,000,000 cycles. and since we don't fully cycle a cap in car audio but just modulate over a few volts and never at rated voltage, we are basically "petting" these things. the 1,500 hour rating is when operating at rated voltage and at rated maximum temperature of 150 deg F. since we don't operate at 150 deg. F we are not concerned with longevity.

https://www.maxwell.com/products/ultracapacitors/docs/datasheet_k2_series_1015370.pdf

and a ton of other literature

Maxwell Technologies - Ultracapacitors - Downloads

the caps i've been buying are used, from solar power energy storage modules. even used they help these vehicles.

but to support your original thread, a standard 1F electrolytic cap is useless unless it is inside the amp and at the rail voltage. i've used and installed them and it made no difference.

also, since ultracaps are much lighter you save fuel. batteries are heavy. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[gstokes]

the main difference between an ultracap and a standard electrolytic cap - the ultracap uses sheets of carbon which have 3,000 times more surface area than metal foil. that's pretty much it. they exploit the concept of capacitance being a function of surface area and distance. increase surface area and/or decrease distance and you increase capacitance. the carbon sheets just have a voltage limitation, hence the 2.7V rating.
the BCAP3000 is rated for 1,000,000 cycles. and since we don't fully cycle a cap in car audio but just modulate over a few volts and never at rated voltage, we are basically "petting" these things. the 1,500 hour rating is when operating at rated voltage and at rated maximum temperature of 150 deg F. since we don't operate at 150 deg. F we are not concerned with longevity.

https://www.maxwell.com/products/ultracapacitors/docs/datasheet_k2_series_1015370.pdf

and a ton of other literature

Maxwell Technologies - Ultracapacitors - Downloads

the caps i've been buying are used, from solar power energy storage modules. even used they help these vehicles.

but to support your original thread, a standard 1F electrolytic cap is useless unless it is inside the amp and at the rail voltage. i've used and installed them and it made no difference.

also, since ultracaps are much lighter you save fuel. batteries are heavy. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

from what i gathered at maxwells site was the ultracapacitor is a combination of a battery and a capacitor giving it the advantages of both types of storage, i have been all over the web today learning about this technology and i am fascinated, i am ready to build my own ultracapacitor bank and i noticed in the video they attached the cap as close as possible to the amplifier using a 8" lead, i guess that maximises the effect of the cap.. I got nothing but time and money so i will just add it to my project list..

 

[butterMilk 10+ year member]

the main difference between an ultracap and a standard electrolytic cap - the ultracap uses sheets of carbon which have 3,000 times more surface area than metal foil. that's pretty much it. they exploit the concept of capacitance being a function of surface area and distance. increase surface area and/or decrease distance and you increase capacitance. the carbon sheets just have a voltage limitation, hence the 2.7V rating.
the BCAP3000 is rated for 1,000,000 cycles. and since we don't fully cycle a cap in car audio but just modulate over a few volts and never at rated voltage, we are basically "petting" these things. the 1,500 hour rating is when operating at rated voltage and at rated maximum temperature of 150 deg F. since we don't operate at 150 deg. F we are not concerned with longevity.

https://www.maxwell.com/products/ultracapacitors/docs/datasheet_k2_series_1015370.pdf

and a ton of other literature

Maxwell Technologies - Ultracapacitors - Downloads

the caps i've been buying are used, from solar power energy storage modules. even used they help these vehicles.

but to support your original thread, a standard 1F electrolytic cap is useless unless it is inside the amp and at the rail voltage. i've used and installed them and it made no difference.

also, since ultracaps are much lighter you save fuel. batteries are heavy. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I remember in one of your installs you had a bank of caps. Do you use a balancing resistor?

If so, are they necessary?

 

[oldschoolboomer 10+ year member]

Wow this thread really takes me back

 

[keep_hope_alive Premium Member]

from what i gathered at maxwells site was the ultracapacitor is a combination of a battery and a capacitor giving it the advantages of both types of storage.

i think you're reading the marketing information. it's still just a capacitor, nothing in it is a battery. a battery would require an AGM or Gel style battery internal, which they don't have. the marketing info tries to explain the concept in simpler terms but when that happens accuracy is lost. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif the advantage is using carbon sheets instead of foil. all caps have an electrolytic fluid inside.

I remember in one of your installs you had a bank of caps. Do you use a balancing resistor?
If so, are they necessary?

no, not needed for a 14.4V system. if you operate the cap bank at it's rating then yes, the regulating circuits are recommended. i use a 75W 5 ohm resistor bank to regulate charge current. it's just three 15 ohm 25W ceramic resistors in parallel.

The only danger with these cap banks is the in-rush when charging from an uncharged state. ever notice a small spark when you hook up the battery? notice how the spark gets larger when caps or big amps are involved? the ultracap banks can pull hundreds of amps in an instant. this means you need to regulate charge current. also, you want a quick disconnect on them so if you disconnect the battery you can also disconnect the cap bank. a cap bank alone will start and run the car. if you were to reconnect the battery to a discharged cap bank, you will likely weld the terminal to the post. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif for that reason, i use a MAXI fuse holder next to the cap bank. the holder gives me a place to insert the charging resistors and also a place for a 100A MAXI fuse that doubles as a quick disconnect.

wire is resistance, so keeping the cap bank close to the load will maximize it's effectiveness. this also helps with dynamics because the cap bank reacts quicker than a battery or alternator can.

 

[bbeljefe]

Kudos OP for seeing you were incorrect and then admitting it. The wisest man is the man who knows he has much to learn, lol. In the world of electronics there are many things that, at first blush, seem counterintuitive at best. Couple that with the fact that technology changes just about as often as we move our bowels and it becomes pretty evident that even those who know the most still have a lot to learn.

 

[i2ain2thunder 10+ year member]

I don't know that anyone has claimed caps to provide "endless voltage" so if that's the claim you're arguing against, then good.
Other than that, capacitors do charge far more quickly than batteries and they can provide current far more quickly than batteries. While it is true that too small a cap won't do you good, it's also true that too short a ladder won't get you to the height you desire. But... that doesn't mean that ladders are completely useless and that they can never provide anyone with enough height to get them where they need to be.

Watch:

[video=eURfjZAVKFY]

Haha, funny. Yeah CAPs aren't the enemy, but usually are not cost effective for the need. The advantage to a CAP vs a Battery is the output is much much more responsive. Caps can drop almost all of their energy very quickly, batteries can't quite achieve the level of output that a CAP can, but that doesn't mean CAPs will help any electrical situation, and the amount of energy they hold is next to nil, I figure they can help with the drop of voltage in your system, but not to a real significant amount to make them cost effective, or to provide you with enough clean power. They make some very large caps that would obviously help voltage drop a great deal and in some people's systems they can help to balance out voltage drops. Batteries and alternators good wires and connections help with this as well and should always be the primary focus in the electrical.

P.S. for the title of the thread "they're" the apostrophe take the place of an "a" (they are) which is the correct type to use in this situation. "Their" shows ownership as in the subs are theirs, not mine.

 

[PSturmer 10+ year member]

lets answer a question. how large of a capacitor do we need to store the same amount of energy as a standard car battery?

energy_cap= .5*capacitance*voltage^2

energy battery= amp-hour*voltage

assume voltage across capacitor 12V, and use 80Ah and 12V for a car battery

one car battery= 48,000 Farad capacitor

 

[keep_hope_alive Premium Member]

lets answer a question. how large of a capacitor do we need to store the same amount of energy as a standard car battery?
energy_cap= .5*capacitance*voltage^2

energy battery= amp-hour*voltage

assume voltage across capacitor 12V, and use 80Ah and 12V for a car battery

one car battery= 48,000 Farad capacitor

except batteries are slow to charge, slow to react, and greatly affected by temperature. the increasing use of ultra capacitors in many industries is not a surprise and a testament to future change. pairing ultra capacitor banks with batteries addresses many of the downfalls that batteries have - including the ability to quickly provide burst of power, and will also prolong the life of the battery.

Maxwell Technologies Ultracapacitors

 

[PSturmer 10+ year member]

except batteries are slow to charge, slow to react, and greatly affected by temperature. the increasing use of ultra capacitors in many industries is not a surprise and a testament to future change. pairing ultra capacitor banks with batteries addresses many of the downfalls that batteries have - including the ability to quickly provide burst of power, and will also prolong the life of the battery.Maxwell Technologies Ultracapacitors

yes this is where capacitors have the upper hand, quick charge and discharge. however, for audio amps, batteries are quick enough. and temperature?additional batteries are usually housed inside the cabin.

 

[gstokes]

let's watch the video again because it is very revealing, one of the first things i noticed was the use of a 1F cap on a 2500W amplifier, at 4~ the amplifier lost 10W of power 1499 > 1489 (-10), if the capacitor was indeed functioning correctly then that would indicate a 1F is indeed too small for a 2500W amplifier and it would also indicate that the use of a capacitor that was too small for the amplifier would actually cause a decrease in power. At 2~ with the 1F cap the rms power decreased from 2059 > 2024 (-35), at 1~ the rms power decreased from 2366 > 2358 (-8), that would confirm that no capacitor is better than the wrong capacitor.

Adding the 100F cap provided some very different results, at 4~ the power increased from 1499

If that's what i needed to gain 32 watts at 4~ and 149 watts at 2~ then i would have to say it is not good investment, at a certain dollar figure you have to question your logic and ask yourself why a bigger amplifier would not be better choice. I would like to see a comparison using the 1F cap on your average 750 - 1000W amplifier, let's see a comparison using the right size capacitor for the application and not using one that is over 2x too small for the intended use and using another that is 4x too big for the application. This would make it easier to determine if a 2.5F cap which is right size for a 2500w amplifier would have provided the same or similar results. Apples to apples and oranges to oranges as they say..

The test also made something else very evident, the voltage drop from the source (alternator 14.01V) to the load (amplifier 13.07V), keep in mind there was 0 gauge cables from the engine to the amplifier and it still encountered a .94V voltage drop, almost 1V at 4~ but as the load impedance decreased the voltage drop increased, 11.84v at 2~ and 10.83v at 1~. If that doesn't convince you that a secondary battery should be located close to the amplifier then i don't know what does but just realizing even 0 gauge cables and a 2~ load is enough to cause a 2.17V drop in load voltage concerns me because i am using 4 gauge so the voltage drop is even greater.

Nevertheless, very revealing test..