Over an entire day, it's 7mWh. The iPhone 12 battery is 10000mWh.
Conclusion: it's neglibile.
It's rather pathetic how Apple restricts user's right to use full capabilities of their devices (like restricting running apps in the background) to 'increase their battery life' while simultaneously be perfectly fine to use that power for their own benefit.
I wonder can a user disable this airtag reporting feature if he doesn't own a single airtag and doesn't want to participate in this surveillance network?
I'm actually quite shocked folks on here do not appreciate that the 'default' is opted-in, rather than not. When you own an Apple iPhone or iPad, you are part of Apple's network, and some of 'your' product is used to be in service of Apple's services. It's not like the requests to send 'user data' back to an app provider 'to help improve the experience' --- it's you Will send data back to Apple because that is the default -- and most people will surely not know the Settings->Apple ID->Find My->Find My iPhone->Find My network seequence.
Does this not seem somewhat fascistic? For the record, I have 2 iPads, and also for the record, I'm an Apple alum -- I have nothing but goodwill for the Company, however, this seems, to me, quite shady. (Downvoters, I'm expressing an opinion. Not polluting HN's polite discourse.)
https://support.apple.com/en-nz/guide/security/sec6cbc80fd0/...
Open the Settings app and search for "Find My". You'll find the setting. Or follow this: Settings->Apple ID->Find My->Find My iPhone->Find My network
There's some explanation as to what it does and you'll be able to opt out if you don't like it. (Though you won't even see the "Find My network" setting if you had "Find My" disabled anyway)