In The Elder Scrolls IV: Oblivion, enchanted weapons have a limited number of charges that deplete with use and need to be recharged to maintain their magical effects. There are four main ways to recharge weapons:

• Use Soul Gems: You can recharge weapons by using filled Soul Gems, which contain captured souls. To fill empty Soul Gems, cast the Soul Trap spell on an enemy and kill it. Different sized Soul Gems are required for different enemy strengths. Once filled, interact with the Soul Gem in your inventory to recharge a weapon. This method is cost-effective but requires some effort to collect and fill Soul Gems

• Use Azura's Star: This is a special reusable Soul Gem obtained by completing Azura's Daedric Quest. Unlike regular Soul Gems, Azura's Star does not break after use and can trap souls of all sizes, making it very convenient for recharging weapons repeatedly

• Use Varla Stones: These rare items fully recharge all enchanted weapons in your inventory at once. Varla Stones are found in Ayleid Ruins and are best saved for later in the game when you have multiple powerful enchanted weapons. They do not respawn after use, so use them wisely

• Pay a Recharger: You can pay NPCs at Mages Guild Halls or the Arcane University to recharge your weapons for a fee. This is the easiest but most expensive method and is generally not recommended unless you are in a pinch

To summarize, the most efficient way to recharge enchanted weapons is to use filled Soul Gems or Azura's Star, while Varla Stones offer a powerful but limited option. Paying rechargers is a last resort due to high cost. Additionally, to check weapon charges in your inventory, enable 'show details' and select the enchanted weapon to see its effects, charges, and uses