That's not a question for this forum, you'd better go to support forum: https://discussions.apple.com/welcome
What iPhone 13 ? Pro Max ? Pro ? standard ? mini ? Are you running apps, having phone call, watch video ? Is GPS active ?
1% every 5 minutes means an autonomy of about 8 hours. Which is normal in case of heavy use.
Here are some figures: https://www.igen.fr/iphone/2021/09/lexcellente-autonomie-des-iphone-13-en-video-125507
Using the iPhones with demanding applications (TikTok, Camera, Instagram, games):
- just under 10 hours of battery life (9 hours and 52 minutes, to be precise) with the iPhone 13 Pro Max - unprecedented!
- The iPhone 13 Pro provides 8 hours 17 minutes,
- the iPhone 13 7 hours and 45 minutes,
- the iPhone 13 mini 6 hours and 26 minutes.