Do you have a schematic of the LED Emergency Flasher unit? You may just have to reduce the current limiting resistor's value. However, LEDs have an upper current limit which, if exceeded, would seriously reduce the life of the LEDs.

Another problem with supplying the lights with a higher voltage is that the electronic flasher circuitry may fail at the higher voltage.

Originally Posted by n0ce

I have built a LED Emergency Flasher unit for the top of my vehicle when doing snow removal.

I was under the impression you'd built them yourself. Hence the advice to modify them too.

If your marker lights are too dim then maybe it is because they are not designed to be bright emergency lights. Emergency lights are high voltage zenon discharge strobe lights, not low voltage and low brightness LEDs.

If you increase the current to your LEDs then they will be bright .... only one time.

As AudioGuru mentioned, a xenon tube would be better and would be just as easy since you are going to use a circuit/coil for voltage boost anyway.
What kind of LED lights are you using? I assume they have a built in current limiting resistor? Could you post a datasheet/link for these lights?

N0ce, a couple volts to an LED is A LOT of current, if you read up a bit you'll also see that efficiency drops when you over current them, and their life expectancy drops faster than the brightness goes up. As a simple example a basic 20mm super bright LED will be 90% efficient between 5 and 10ma, then the efficiency drops to 80% as the current goes to 20ma, then it basically goes down linearly losing 1% per ma of higher current, and again brightness does not go up linearly with current, 5 times the current will only get you twice the brightness.

That's interesting. Somehow, the commercial units are achieving great brightness. I thought it must be because they are suppying the LED's with a short pulse of higher voltage, thereby not damaging the LED's.

I am supplying 13.8 volts from a charging 12V system to the lights. The lights have dropping resistors built in. So a 2 volt increase in the supply will be a small increase in current to the LED's. I had hoped to use 15-16 Volts. That would be an 8-16 % increase to Vs. Also, the duty cycle was engineered for 100% and when pulsed, it would be a fraction of that.

Your vision sees 30ms and longer as being a certain brightness. Shorter durations appear dimmer.

You can buy cheap Chinese no-name-brand LEDs that appear bright but are focussed into a narrow angle to appear bright.

Or you can buy name-brand high power, wide angle LEDs.

A huge difference.