Indicate Pairs based on Given %

Hi there,

I am putting together a battery log that keeps track of battery capacity in percentages. The goal is to pair two batteries with the closest percentages together. As you will see in the attached sheet, I have indicated those pairs with asterisks (*). Is there a way for the sheet to indicate pairs automatically? I am not sure how it would display, but I was thinking that it could indicate pairs by cell colour perhaps? I am open to ideas and look forward to hearing your solution!

* AliGW has solved the above for which I'm grateful. I should have noted earlier that an odd number of batteries may be logged in which case one battery can not be paired. One solution brings forward another problem, so it seems! I would not mind if the one odd battery gets displayed a blank cell. I will be tinkering with it in the meantime.