The process of recharging a teleport crystal in OSRS starts with finding Eluned, who can be located in many places depending on your quest progress.
I find that the most reliable way to recharge your teleport crystal is to visit Eluned near the magic trees outside Lletya or in the clearing northeast of Tyras Camp, if you haven't completed Song of the Elves.
For players who have completed Song of the Elves, Eluned can be found in southwest Prifddinas, close to the player-owned house portal and Guinevere's Dyes.
The recharge cost varies from 750 coins for your first recharge to 150 coins after your fifth recharge.
Before you spend time searching for Eluned, you might want to consider buying OSRS gold to make sure you have enough coins for multiple recharges.
Your teleport crystal must be completely depleted of charges before it can be recharged. When all charges are used, it transforms into a crystal teleport seed.
Each crystal initially comes with four charges, though players who have completed the Hard Western Provinces Diary can receive up to five charges per recharge.
After Song of the Elves, you gain an additional option to recharge your crystals through the Elven scout, who can be found at Eluned's former locations. This provides flexibility in where you can recharge your crystals.
For those seeking a permanent solution, crafting an eternal teleport crystal eliminates the need for regular recharging, though this option only becomes available after completing Song of the Elves.