[garmageddon]

I'm no electrician by no means, but I only have halos and LEDs on my rigs and I was curious on what the ballast does for the hps lights. I'm swapping the halos after this season to hps on my bigger rig.

 

[mattman]

From what I understand they are for a faster warm up on the lights and also feeding the light a constant power supply. making it better for the lights and the genny

 

[NuffDaddy]

Basically, a ballast regulates the voltage to the bulb. You must have them for any HID (HPS or MH) bulbs and florescent bulbs. Without them the bulb will burn up and can be dangerous if it explodes.