IPhone charging cable not supported but still charging?

I have a genuine Apple cable that came with my iPhone 6 (updated to the latest iOS). It fully charges up but when it gets to 100% I get a message that says "this accessory may not be supported". I don't see any damage to the cable and I have only had it a couple of months. Not sure whether to just ignore it or not?

Mine did that, I talked to a lot of people and figured out that it is that charger, and those are really bad for your phone. I ignored it for the longest and it completely ruined my phone and I have a iPhone.
I ordered a charger online that was the original kind ( apple ) and it stopped.
xx!

Go to the apple store and let them know about this As soon as possible! The longer you continue to use it and the longer you ignore the problem it will eventually ruin your iphone and you won't be able to charge it anymore. They will gladly give you another charger. You are better off replacing it with another apple charger because anything that's not apple is not really appropriate for your phone.