Capacitors used with HID lights?

[J-440]

 I have downloaded the headlight relay diagram posted awhile back and will be using it as reference for my install.  I have also heard that a capacitor on each light would help.  There has been no mention of capacitors used in conjunction with the relays.  Would I be wasting time doing a capacitor install or will the relays suffice?

[Dino]

The relays should suffice.

[J-440]

 Thanks Dino.  Preciate it.

[MaximRecoil]

Capacitors on the headlights would only help if your headlights are dimming due to something else in your car that is drawing high current. First of all, you would need huge capacitors in order to have any practical effect, e.g., 1 farad, 16v, about the size of a 16 oz. beer can (or a large array of small "super capacitors" wired in a specific way so that you end up with enough capacitance and high enough voltage handling). Second, it would be a Band-Aid solution to the underlying problem of a weak electrical system that can't meet the demand being placed on it (a higher output alternator and upgraded charging circuit wiring and relevant grounds to handle it would be the correct solution).

[JamieZ]

Are you sure it was caps and not diodes?  Some headlight relay set ups I have seen use diodes across a few of the feet of the relay to reduce the electrical noise the radio picks up.