Why do wireless keyboards have battery corrosion after awhile?

Scott from Springfield, PA

Episode 1275 (2:13:02)

Apple wireless keyboard

Scott has an Apple wireless keyboard, but now there is some battery corrosion and he can't get it out to clean it. Leo says this is why you should always remove a battery if you're not going to use a device for awhile. Leo advises bringing it to the Apple store. Scott did and Apple ended up replacing it free of charge. Leo says that's why you pay more for Apple.