Get the batteries out and wipe the electronics with a soft towel soaked with a little vinegar to neutralize the corrosion. Then a damp towel with just water to get the vinegar up. Let it fully dry before putting in new batteries. This happens to batteries that have sat unused for a long time installed. It can also happen if at the end of charge, you pull the batteries out, and put them back in to squeeze a little more use out of the batteries. Do it too many times and there is a leak risk. Cheaper batteries do it more often but the top brands will occasionally leak as well.

OP must be pretty young 😂, we old fucks have seen this happen 100 times

Every '90s kid remembers this!

Yes? It was extremely common as a child because all our toys were battery powered (but not included)

You know, at first glance these looked like 2 dollar bills rolled up to do coke with and these were after a couple of hours of use and the coke was getting gummed up around the snorting side. My first thought was “Yeah, I’m familiar with that.”

Ah, the forbidden salt. Yes, I remember it fondly from when I was but a young boy, playing the GameBoy Color.

Do not leave batteries inside things your not gonna be using for a long time. And if you don’t want this to happen buy NiMH batteries

This was so incredibly common before rechargeable batteries. Alkaline batteries may have had the best life but the worst death.

Sure, dust our with a paintbrush…wipe down with some alcohol. If the contacts are corroded either file or use a dot of lemon juice and a toothbrush to remove and then either spray with contact cleaner or wipe again with alcohol.

I lost my favorite mouse this way :(

Make sure to take ya batteries out if you’re putting electronics in long storage!

Several times in my own electronics and many times in secondhand items. The potassium hydroxide electrolyte never quite evaporates and seeps under the crevices, requiring a full disassembly to prevent further corrosion.

Worst offenders are the pesky little alkaline button cells. Every alkaline cell inevitably evolves hydrogen gas as the electrochemical reaction proceeds and in those tiny canisters, the gas very quickly has nowhere to go but out along with the cell’s guts. The secret is to get the silver oxide versions, same voltage, a bit pricier, but far less leakage.

I guess the silver lining to the declining popularity of AA and AAA powered devices is that I can finally afford to use only Ni-MH or primary lithium cells in all of my devices. Those chemistries are mostly immune to leaking.

3 or 4 times at least

Happened in my Wii remotes all the time when I was kid, only ever lost one to battery corrosion though, and that was about a decade later

Yes that’s what they’re called alkaleaks.

yeah it tastes like donut creme