28 replies to this topic

[WALKER]

Hi,

Just quietly saying the knowledge in this thread is invaluable. Thanks for contributing guys!

Cheers,
Nik

+1

Thanks guys.

[Tim.]

With the battery sitting at 12v, the usable power of the capacitor is only 2v, or 12 joules. Now, you can't use more than 12 joules because that would place the capacitor in the range of where the battery starts being used.
The only way in which the power stored in the capacitor can be used would be to turn off the alternator or have power to its outputs drop (read overloaded).

Hey Chris, just to spark up a bit of discussion....

I'm not sure that the use of a capacitor in a car is for the reason you've described. A capacitor is not for supplying constant current and isn't supposed to be used as a primary power source as such. It is purely for filtering line voltage - ie. supplying instantaneous current or voltage when the vehicle's electrical system cannot keep up with the demand of the audio system.

I guess you could think of it as a surge tank as opposed to a fuel tank.

That being said, i don't see the point in putting a capacitor in a car. I run two fairly large amps, a slightly larger battery and don't have any issues with the electrical system in my car.

Tim.

[SUBARU]

Hey Chris, just to spark up a bit of discussion....

I'm not sure that the use of a capacitor in a car is for the reason you've described. A capacitor is not for supplying constant current and isn't supposed to be used as a primary power source as such. It is purely for filtering line voltage - ie. supplying instantaneous current or voltage when the vehicle's electrical system cannot keep up with the demand of the audio system.

I guess you could think of it as a surge tank as opposed to a fuel tank.

That being said, i don't see the point in putting a capacitor in a car. I run two fairly large amps, a slightly larger battery and don't have any issues with the electrical system in my car.

Tim.

Nothing like a good ol' discussion! However, I think you might have misunderstood what I was trying to say. I never said that a capacitor is, or could be used for constant supply or as a replacement for the vehicle's electrical system.

The example I've used above indicates the power the capacitor is able to store (approx 12 joules for a 1 farad cap), in preparation for spikes in voltage required by an audio system which might take over and above what the vehicles' electrical system can actually deliver.
Also trying to demonstrate just how quickly that storage is used, with power then being drawn straight from the alt/batt, through the cap and into the amp. Rendering the capacitor, well, useless. An electrical paper weight if you like.

[Tim.]

Exactly, they do store bugger all energy but they can supply it very quickly.

I don't see how you would benefit from installing one but do see how you could be fooled by the marketing hype surrounding them.

[WALKER]

Exactly, they do store bugger all energy but they can supply it very quickly.

I don't see how you would benefit from installing one but do see how you could be fooled by the marketing hype surrounding them.

cause its shiny..

[Sam]

Nothing like a good ol' discussion! However, I think you might have misunderstood what I was trying to say. I never said that a capacitor is, or could be used for constant supply or as a replacement for the vehicle's electrical system.

The example I've used above indicates the power the capacitor is able to store (approx 12 joules for a 1 farad cap), in preparation for spikes in voltage required by an audio system which might take over and above what the vehicles' electrical system can actually deliver.
Also trying to demonstrate just how quickly that storage is used, with power then being drawn straight from the alt/batt, through the cap and into the amp. RENdering the capacitor, well, useless. An electrical paper weight if you like.

[SUBARU]

^ ??

[RX25SE]

I think he's having a dig at another member Chris.

[SUBARU]

Ahhh, I see. A bit slow today.