Halogen bulbs are 55w (input and output). HID bulbs (capsules) are 35 input, 175 watts output. The current draw is less than 3 amps for an HID capsule. Sounds like an issue with your ballasts or your light control module.
Do you have a computerized "system check" on your car? If so, it will read that the low beams are burnt out (no 'filament' in an HID capsule). But this shouldn't make them "blink"