White and blue stuff coming out of Wii Remote batteries

[Stitch]

I was trying to find my other Wii remote and saw some white crusty stuff around the battery cover. I brushed it off and then remembered I saw something similar around the batteries in my sister's Wii remote. I opened it up and saw a load of white stuff and a bit of blue all over the batteries inside.

I've only ever seen this happen to batteries in Wii remotes so what is causing this?

[GommeInc]

When was the last time you used either of the Wii machines? This is what happens when you leave batteries in something for a long time and the batteries lose any charge in them. They split and leak acid everywhere. It can be very messy and can cause permanent damage to whatever the batteries were where you may not be able to use them again because the conductors erode and can't pick up the power from the batteries. That's my guess at least :/

[Special]

the barreries are old or 'out of date' which has caused them to leak

you should change them and if the problem still persists, the battery liquid has effected the metal stuff inside the remotes so you'll have to get new remotes