In decent light look at the lens. The codes will tell you what they are. There are fakes - sometimes they can be figured from the codes not making sense. LOL.
US market lamps will have HR for Halogen Replaceable. They are designed for the HB2 bulb, almost the same as H4.
ECE market lamps will have HCR and take H4 bulb.
The higher the voltage they get, the more current they will draw. On battery power they're getting 12.8 V at best.
If you go to that Candlepower thread with the H4 bulb comparison, you can see the difference higher voltages make in current and light output.