A 10-Year Battery for AirTag

If you could disable the public key rotation on the AirTag, presumably you could greatly extend its battery life at the cost of your own privacy. When your battery gets low, Apple warns that "privacy protection is temporarily adjusted, AirTag may be traceable over Bluetooth". Wish I could enable this behavior in certain situations to extend the life.

(Or hook up an oversized external battery like this one, but tune the voltage to ~2V so it always looks like a nearly depleted CR2032 battery!)

I doubt that key rotation is a significant contributor to energy use. Energy spent doing RF (transmitting) plus energy spent sleeping will account for over 90 % of the energy use.

Source: I'm in a similar industry

I think the airtag just wakes up less frequently on low power, so it has fewer opportunities to rotate the key.