Looks like those bulbs run off 12V and 100-250mA. If you’re stepping 5V up to 12V, you’d need 600mA to get the same 3W. That’s a lot of power. But less than 1/10th of what my board is capable of delivering. Need some kind of module though. Could be something to upconvert voltage, but would be better to feed it directly from the battery. Doesn’t make sense to convert 8.4V down to 5V then back to 12V. Waste a lot of power as heat.
I’ll look into it. It’s totally doable. I just haven’t had a chance yet to look into the best way to drive high power leds. This might be a cheap and easy setup though. I wonder if the current on those even needs to be regulated. I doubt it if they are designed to just plug into a car’s light socket. On the other hand, if they don’t require a heat sink you’d think they couldn’t be as bright as some high power leds you can get. But if they’re made for headlamps they must be really bright. Hm… Wish I had a datasheet.