Xbox one controller randomly started killing AA batteries in an hour

This is the second controller my son has had this happen to. One that has barely even been used since purchase. I can’t find any rhyme or reason that it would randomly start eating them that quickly anywhere on the internet. Hasn’t been dropped a bunch, or mistreated in any way. Any suggestions would would be awesome. Even if it’s not fixable, I would really like to know what is happening. He does sweat a lot, but that doesn’t seem like it would have that kind of effect

I would suspect a short somewhere if it is killing batteries that fast.