How often should the Cap be charged?
Registered User
Joined: Feb 2004
Posts: 1,154
From: VA
Registered User
Joined: Nov 2000
Posts: 1,858
From: OHIO Go Buckeyes!
Super Moderator
Joined: Jul 2005
Posts: 9,507
From: Okemos, MI
You do not need to charge a capacitor. It's charged by the car's electrical system (battery/alternator) automatically. Its purpose is to provide a way for a lot of current to reach the amplifier quickly without the need for an alternator rated at that level of current. It's basically a reservoir. When your music demands a lot of power (typically when there's a lot of hard-hitting bass), it draws energy from the capacitor. Then, during less demanding sections of your music, the alternator recharges the capacitor.
It works pretty much the same way as a water tower. There's a pump that is always putting water in the water tower (unless it's full), but sometimes the community's water demands are higher than the pump can satisfy. The water in the water tower makes up the difference. The level goes down during high-demand periods, and the pump fills it back up during low-demand periods.
Watts = Amps * Volts.
Farads = Amps * Seconds / Volts
Technically, caps could be rated in watts if they also included a time rating (e.g. 1000w for 30 seconds). If they leave the time rating out, then they're telling you how quickly the cap can disperse energy (i.e. how large of an amp it can support), but now how deep its reserves are (i.e. how long you can listen to very demanding music).
In a car audio application, the wattage rating is more important. Even the smallest car audio capacitors (I've seen 0.25 Farad units) can store more than enough energy to provide the backup power needed.
Most car audio systems don't need capacitors. An amp rated at 1200w, assuming the rating is accurate, draws a maximum of 83 amps at 14.4 volts. Most alternators these days provide at least 90 amps, and more often 100 or more. This means that your alternator is enough to do the job, which means you don't need the cap.
Moral of the story? Sell the cap to some fool who doesn't understand and save your money for something that matters.
Registered User
Joined: Jul 2005
Posts: 133
From: IN/OH
Since everyone else is just giving you crap...
You do not need to charge a capacitor. It's charged by the car's electrical system (battery/alternator) automatically. Its purpose is to provide a way for a lot of current to reach the amplifier quickly without the need for an alternator rated at that level of current. It's basically a reservoir. When your music demands a lot of power (typically when there's a lot of hard-hitting bass), it draws energy from the capacitor. Then, during less demanding sections of your music, the alternator recharges the capacitor.
It works pretty much the same way as a water tower. There's a pump that is always putting water in the water tower (unless it's full), but sometimes the community's water demands are higher than the pump can satisfy. The water in the water tower makes up the difference. The level goes down during high-demand periods, and the pump fills it back up during low-demand periods.
Watts = Amps * Volts.
Farads = Amps * Seconds / Volts
Technically, caps could be rated in watts if they also included a time rating (e.g. 1000w for 30 seconds). If they leave the time rating out, then they're telling you how quickly the cap can disperse energy (i.e. how large of an amp it can support), but now how deep its reserves are (i.e. how long you can listen to very demanding music).
In a car audio application, the wattage rating is more important. Even the smallest car audio capacitors (I've seen 0.25 Farad units) can store more than enough energy to provide the backup power needed.
Most car audio systems don't need capacitors. An amp rated at 1200w, assuming the rating is accurate, draws a maximum of 83 amps at 14.4 volts. Most alternators these days provide at least 90 amps, and more often 100 or more. This means that your alternator is enough to do the job, which means you don't need the cap.
Moral of the story? Sell the cap to some fool who doesn't understand and save your money for something that matters.
You do not need to charge a capacitor. It's charged by the car's electrical system (battery/alternator) automatically. Its purpose is to provide a way for a lot of current to reach the amplifier quickly without the need for an alternator rated at that level of current. It's basically a reservoir. When your music demands a lot of power (typically when there's a lot of hard-hitting bass), it draws energy from the capacitor. Then, during less demanding sections of your music, the alternator recharges the capacitor.
It works pretty much the same way as a water tower. There's a pump that is always putting water in the water tower (unless it's full), but sometimes the community's water demands are higher than the pump can satisfy. The water in the water tower makes up the difference. The level goes down during high-demand periods, and the pump fills it back up during low-demand periods.
Watts = Amps * Volts.
Farads = Amps * Seconds / Volts
Technically, caps could be rated in watts if they also included a time rating (e.g. 1000w for 30 seconds). If they leave the time rating out, then they're telling you how quickly the cap can disperse energy (i.e. how large of an amp it can support), but now how deep its reserves are (i.e. how long you can listen to very demanding music).
In a car audio application, the wattage rating is more important. Even the smallest car audio capacitors (I've seen 0.25 Farad units) can store more than enough energy to provide the backup power needed.
Most car audio systems don't need capacitors. An amp rated at 1200w, assuming the rating is accurate, draws a maximum of 83 amps at 14.4 volts. Most alternators these days provide at least 90 amps, and more often 100 or more. This means that your alternator is enough to do the job, which means you don't need the cap.
Moral of the story? Sell the cap to some fool who doesn't understand and save your money for something that matters.
Super Moderator
Joined: Jul 2005
Posts: 9,507
From: Okemos, MI
No, a cap doesn't really help if you're running underdrive pulleys. Except at idle, underdrive pulleys have no effect on your alternator's performance. Once the revs are at, say, 1000rpm, you'll never know the difference.
A cap will only help when your system demands more current (amps) than your alternator can provide.
If you're concerned about voltage at idle with an underdrive pulley, get an overdrive pulley for your alternator (so that it spins the same speed it did when you had stock pulleys). I know that when I eventually get around to installing an underdrive pulley, I will get a kit with an alternator overdrive pulley.
If your lights dim when the bass hits on your car, get a better (higher amps) alternator. Forget about caps altogether.
A cap will only help when your system demands more current (amps) than your alternator can provide.
If you're concerned about voltage at idle with an underdrive pulley, get an overdrive pulley for your alternator (so that it spins the same speed it did when you had stock pulleys). I know that when I eventually get around to installing an underdrive pulley, I will get a kit with an alternator overdrive pulley.
If your lights dim when the bass hits on your car, get a better (higher amps) alternator. Forget about caps altogether.
Registered User
Joined: Jul 2005
Posts: 133
From: IN/OH
No, a cap doesn't really help if you're running underdrive pulleys. Except at idle, underdrive pulleys have no effect on your alternator's performance. Once the revs are at, say, 1000rpm, you'll never know the difference.
A cap will only help when your system demands more current (amps) than your alternator can provide.
If you're concerned about voltage at idle with an underdrive pulley, get an overdrive pulley for your alternator (so that it spins the same speed it did when you had stock pulleys). I know that when I eventually get around to installing an underdrive pulley, I will get a kit with an alternator overdrive pulley.
If your lights dim when the bass hits on your car, get a better (higher amps) alternator. Forget about caps altogether.
A cap will only help when your system demands more current (amps) than your alternator can provide.
If you're concerned about voltage at idle with an underdrive pulley, get an overdrive pulley for your alternator (so that it spins the same speed it did when you had stock pulleys). I know that when I eventually get around to installing an underdrive pulley, I will get a kit with an alternator overdrive pulley.
If your lights dim when the bass hits on your car, get a better (higher amps) alternator. Forget about caps altogether.
Registered User
Joined: Aug 2006
Posts: 121
From: St. Pete, FL
.......
CAPS ARE A WAISTE OF MONEY
They do nothing put a strain on your alternator. They let their energy for a large hit and then must re-charge putting strain on the alt.
Do your Big 3 and run 0 gauge to the distro block and you will have MUCH better results than a Cap could provide.
CAPS ARE A WAISTE OF MONEY
They do nothing put a strain on your alternator. They let their energy for a large hit and then must re-charge putting strain on the alt.
Do your Big 3 and run 0 gauge to the distro block and you will have MUCH better results than a Cap could provide.
Registered User
Joined: Mar 2005
Posts: 194
From: Charlotte, NC
.......
CAPS ARE A WAISTE OF MONEY
They do nothing put a strain on your alternator. They let their energy for a large hit and then must re-charge putting strain on the alt.
Do your Big 3 and run 0 gauge to the distro block and you will have MUCH better results than a Cap could provide.
CAPS ARE A WAISTE OF MONEY
They do nothing put a strain on your alternator. They let their energy for a large hit and then must re-charge putting strain on the alt.
Do your Big 3 and run 0 gauge to the distro block and you will have MUCH better results than a Cap could provide.
I would agree with doing the big three, thats the best way to help your cars electrical system, along with maybe a ~200 amp alternator, depending on what you are running. And from my experience, a cap is a huge waste of money.
Registered User
Joined: Mar 2005
Posts: 194
From: Charlotte, NC
http://www.mean-green.com/products/alternator.html
