Power reserve is not “the last few percent”, it’s up to 5 hours after you have run out of battery. https://support.apple.com/en-is/guide/iphone/iph0475909d4/io

Power reserve is not “the last few percent”, it’s up to 5 hours after you have run out of battery. https://support.apple.com/en-is/guide/iphone/iph0475909d4/ios#:~:text=You%20may%20be%20able%20to,have%20Express%20Mode%20turned%20on https://support.apple.com/en-is/guide/iphone/iph0475909d4/io....