MakerSpace & the Toy Doctor: Patient Matoki Bunny

Banner that says MakerSpace and the Toy Doctor with a needle and thread and a sewn heartPicture of a Kpop lightstick for the band BAPToday's patient is Matoki Bunny, a lightstick for the Korean pop group, B.A.P! Lightsticks are used by fans at concerts instead of lighters to show the fans' love for their group. They become part of fun memories of concerts, and can be highly sought after collectibles.

This one is well-loved by his owner, as it's named after her favorite band member. He had lots of fun lighting up and bouncing in the air when B.A.P went on American tours, then he took a nap in a closet for a few years… with the batteries inside. They leaked and corroded the connections and he didn't light up anymore. His owner didn't want to replace him because of her memories (and lightsticks can be hard to find), but was upset he didn't work.

Toy Doctor to the rescue!

picture of a Kpop lightstick getting the battery compartment cleanedWarning: whenever you're working with battery leakage, please be careful, wear gloves if necessary, and dispose of the waste properly!

So first I removed Mr. Bunny's old batteries and cleaned up as much of the leak as I could with some napkins and baby wipes. A quick test - Mr. Bunny still didn't light up. So, time for some chemistry.

The leakage from alkaline batteries is chemically basic (while we call it "battery acid" that's not necessarily correct - it just depends on what the battery is made of.) So to neutralize a basic compound, you need an acidic compound.


picture of the pH scale about acidic and basic compounds

Picture of lemon juice, a toothbrush, and the open battery compartment of the lightstickLemon juice or white vinegar both work! They're both acids and can be found in the kitchen for quick fixes like this. (if the battery had an acidic compound, you could use baking soda as a basic compound instead.) You can see on the pH scale above that lemon juice and baking soda are on opposite ends of the scale. It's just knowing what balances out the stuff you're trying to clean up.

I dabbed this old toothbrush in the lemon juice and carefully scrubbed off all the connections inside the battery compartment. I soaked up the lemon juice and loose gunk with napkins, then did it again to make sure it was extra clean. To really get in there I also used a q-tip. Be careful to not jostle the wires or soldered connections inside the battery compartment, or you'll just make some more work for yourself.

I blasted some compressed air to make sure Mr. Bunny is completely dry, then came the test. Popped in his new batteries and-

picture of a Kpop lightstick glowing green in the darkMatoki Bunny lights up and is ready for concert duty!

(His owner also now knows to always remove batteries from electronics and toys if you're not going to use them for a while.)



Interested in Kpop? Listen in on our international CD collection!

Want more practical application of science? Check out some of our books with at-home experiments and see how to apply it to your world.

Also, try out our new STEM kits! They're fun interactive kits that focus on the principles of Science, Technology, Engineering, and Math!

Happy Making!

Posted by DanieE on September 1, 2021