I had a flashlight containing 4 leds.

It worked on four button cells of 1 volt each.

Each white led can take upto 3 volts. So 4 leds could take upto 12 volts.

I decided to remove the four button cells and add a 9 volt battery to the flashlight.

Conversion:

So i soldered a battery cap to the four leds.

(Black wire of the battery cap to the negative of the LED and red wire to the positive of the LED assembly. )

Result:

Final result was a powerful flashlight!

Potential 12 volt leds, earlier running on 4 volts, now running on 9 volts!

This conversion can be done on any flashlight with more than 3 LEDs.

Happy with the outcome! ;-)

Step 1: Images

Step 2: My YouTube Videos: