Craft 9 XP Bottles (Bottle o' Enchanting) to make 1 Large XP Bottle. This can be used to help store XP and use it to repair items faster.

Here are the calculations for different amounts of both types of XP Bottles:
1 Large XP Bottle -> 50 XP, or 4 Levels and 10 Points
64 Large XP Bottles -> 3200 XP, or 41 Levels and 78 Points

1 XP Bottle -> 3 - 11 XP (Average 7), or 0 Levels and 3 Points - 1 Level and 4 Points (Average 1 Level)
9 XP Bottles, equal to 1 Large XP Bottle -> 27 - 99 (Average 63) XP, or 3 Levels - 7 Levels and 8 Points (Average 5 Levels and 8 Points)
64 XP Bottles -> 192 - 704 XP (Average 448), or 11 Levels and 5 Points - 22 Levels and 25 Points (Average 18 Levels and 7 points)
From testing, I have found that you can fully repair a broken Mending Netherite Chestplate (592 Durability) with just 6 Large XP Bottles (300 XP). Each  Large XP Bottle restores 100 Durability to a random armor piece.

This datapack runs without a tick function to reduce lag.

I tried to make a resource pack with the icon as the item texture, but unfortunately it is either impossible or very hard to remove the color from the spawn egg, so any texture would be dark green.