Batteries leaking?

[mxchanical]

Hi there, my drone has been in storage for a while (just under a year) and I was going to start flying it today. I noticed some sticky substance, slightly dried, on 2 of the batteries. It looks like sticker residue, but I do not remember sticking anything. There is no smell or bulging. Any ideas if it is leaking/if it is safe to charge?

By slightly dried, I mean I can wipe it if I really try to. But it does not just come off easily

 

[Cafguy]

Take some 91% Alcohol with a rag and clean it. Its not from the Batteries unless it was a sticker. Charge them!