Looks like you possibly had juice leak on the battery or worst case cicero, the battery vented and you see discoloration from heat or chemical release. Have you overheated the batteries, if yes, get rid of them.Samsung r25
Well lets say they vented, do not use them. One other route would be to remove the wrap and inspect the battery, doing this and the battery looks good, you would have to rewrap the battery. Being that batteries are really inexpensive, replace them to be on the safe side. I attach a link to a vendor that many of the VU members use, honest and reliable.No i never personally felt the heat off the batteries and they dont normally get hot at all. Is it ok to use for a few days or is it ditch them as fast as possible?
I have dropped them a time or two though