At night when camping or having a campfire in your back yard. Finding 'your' drinks in the cooler is a pain. You cannot see what drink is yours in the dark of night. Then you freeze your hands fishing around in the ice pulling several out that are not yours. Finally, in pain, you pull your frozen club of a hand out with your drink.
You can put a puck light your cooler but remembering to turn it off after you crawl into your tent or once the party is over never happens. Lets face it, batteries are not cheap. I don't want to buy new batteries each time you use the light and also don't want to be in the middle of the woods, open your cooler and remember that the batteries are dead and that you should have changed them when you got home.
Here is a $5-15min solution to your first world woes.
I do not have a night picture of this working... low light pictures suck... Attached is a snapshot of it working in my kitchen. I am sure you get the idea of it and how handy this little bad boy is
Annnnd... here is a video we have done on this build if you need any clarification on any of the steps