I have a headlamp that runs on (3), AAA batteries. I use it when doing barn chores at night.
The AAA batteries don't last very long, so I was thinking of attaching a 4.5 volt, rechargable pack that is larger than the 1 amp hour AAA cells that it currently uses.
I thought that using a rechargable USB pack might be an easy way to do this, but USB is 5 volts.
Can my LED light handle 5 volts instead of 4.5, or is that going to eventually destroy the circuit? If the latter, what is the simplest way to drop the voltage? A resistor? What wattage? Use P=I*E? I'm guessing I can use ohms law, while measuring the current draw of the light to figure out the required resistance as well.
Thanks