How do u charge the blade when it says like 10/1000 how do u make it 1000/1000

any mages guild or some armorers will re enchant your magic weapons charge to make it go back to full charge, its pricey to do so though

It's been a while since I played Oblivion (had it for PC). I believe you can also recharge enchanted items by using a charged soul gem, or by using a varla stone (found in some Ayleid ruins).