In The Elder Scrolls IV: Oblivion, you can recharge enchanted weapons in several ways:

• Pay a Recharger NPC: Visit Rechargers found mainly at Mages Guild Halls or the Arcane University across Cyrodiil. These NPCs offer a service to recharge your weapons for a fee, which can be very expensive. For example, in the Imperial City, the Mystic Emporium in the Market District has a recharger NPC. Other Mages Guild locations with rechargers include Anvil, Bravil, Bruma, Cheydinhal, Chorrol, Leyawiin, and Skingrad

• Use Filled Soul Gems: You can recharge weapons by using filled Soul Gems in your inventory. To fill Soul Gems, cast the Soul Trap spell on an enemy and then kill it. Soul Gems come in various sizes, with larger ones holding more charge. Azura's Star is a special reusable Soul Gem obtained from a Daedric quest that can trap souls of all sizes and be used repeatedly to recharge weapons

• Use Varla Stones: These rare items fully recharge all enchanted weapons in your inventory at once. Varla Stones are found as loot in Ayleid Ruins. Because they are limited and do not respawn, it is best to save them for later in the game when you have multiple powerful enchanted weapons

In summary, to recharge weapons in Oblivion, you can go to Mages Guild Halls or the Arcane University and pay a recharger NPC, use filled Soul Gems (which you can fill yourself using Soul Trap), use Azura's Star for reusable soul trapping, or use Varla Stones found in Ayleid Ruins

. The most convenient but costly method is paying a recharger, while using Soul Gems or Azura's Star is more economical for long-term play.