We hear this question all year! In a perfect world battery lights would stay on you know… forever. Unfortunately, the type of light bulbs, the size of the batteries and the quality of the batteries combine to make this question longer to answer.
Short Answer
As a rule of thumb, incandescent light strings with 10-15 lights should last about 3-6 hours on C-battery set. Microdrop LED lights constructed on thin uncoated wire should last over 100 hours with a fresh set of 3 AA batteries or 2 round C-style batteries and standard LED battery light sets with thicker insulation and LED lenses should last about 18-24 hours on a set of 3 AA batteries.
Keep in mind that battery lights will only perform as well as their batteries. Cheap, old or off brand may not provide the same results as a mainstream brand of batteries purchased at a high traffic store with lots of battery turnover.
Maybe that wasn’t so short. Here’s the ….
Longer Answer
Pictured from left to right in the photo below: micro drop LED lights with 3 AA batteries, standard glass mini lights with C batteries, LED lights with 3 AA batteries and micro drop LED lights with C type batteries.

Micro Drop Battery Lights – About 100 hours
The set shown below is a set of micro drop LED battery lights manufactured with a battery box that works with 3 AA batteries. This set of lights lasts over 100 hours depending on the brand and age of the batteries.

These micro drop lights are manufactured with CR type batteries and last about 100 hours per battery set as well.

Incandescent Battery Lights – About 4-7 hours
This set of traditional glass battery lights has 15 bulbs and takes 2 C batteries. Since these incandescent bulbs use heating of a filament to produce light, they only last 4-7 hours per set of 2 batteries. They have the advantage of being economical and cast

LED Battery Lights
These LED battery lights with larger lenses and green or white insulated wiring aren’t as energy efficient as the micro drop versions of LED battery lights but their larger lenses complement the lenses on LED light strings. So these battery sets work together with traditional LED string lights to create a cohesive look. These light sets last 18-24 hours per set of 3 AA batteries.

Hi Shellie–This may not be something you can answer, but I thought I’d ask. I’m trying to make it as hard as possible for my cats to catch birds. I’ve tried multiple loud bells, but that’s not working as well as I’d hoped. It occurred to me that rope light “collars” might work, especially if the lights flash. Is it possible to create such a thing that operates on a small, flat battery that I can turn on-off easily (so it’s only on when the cats are outside)? Do you have any ideas or suggestions?
Hello Sheila,
David and I have just bounced your issue back and forth and you’ve really given us something to think about!!
We are concerned that if a big bell isn’t alerting the birds, we’re not sure what would be a better deterrent than that.
We have seen LED pet collars that can be purchased online but if bells aren’t working we aren’t sure this would be any better. Nevertheless, we thought we’d throw it out as a suggestion.
These collars would be light and USB rechargeable. Good luck with your project and let us know if you find anything that works.
And we commend you on trying to maintain the songbird population in your neighborhood!
Shellie