When ever you freeze bananas make sure you remove the skin. Then place in a freezer bag for safe usage. If you add lemon juice and water , sprinkle or dip the bananas will help them last longer in the freezer. I use my banana for smoothies in the summer on a regular bases. So, I do skip this process, my use of banana is for smoothies .
If you see the bananas sitting on the plastic baggie have been frozen for two weeks and by example have not browned or changed in appearance to the one peeled.
This photo in no way has been altered. But, don't let the bananas over ripped before freezing. These would not be good for freezing only making banana bread.
The photo shows the right time for freezing, you might get a few more days before you have to freeze them, This is just a good example for when the best time to freeze a banana.