Need suggestion please

I'm a new iPhone 15 user, complete noob to iOS. For 2 months and 17 days, I've been charging it with a Motorola 68W PD charger, without a SIM card installed. After a recent update, my battery health droped to 99% with just 25 charge cycles. I'm concerned about the battery health. Do I need to buy apples power brick or just continue with PD charger ignoring this battery health percentage?