This is some serious "c-suite message to help you fall asleep at night territory".
He doesn't care how long the total life span is. It's perfectly capable of it (access to the option can be paid for so it's not equivalent to a hack) and he wants to go further on a single charge, so this is a perfectly reasonable tradeoff to make.
Just let the user make that choice without an absurd subscription.
Phones are designed that way as a way to prolong the longevity of the phone. This bike is designed this way as a way to extract a subscription. These two things are not the same.
In this scenario, have them do step 3..
3) push the button a second time.
I don't see anything inconsistent with a subscription if the manufacturer is responsible for replacing the battery during a warranty time. I prefer large ecosystems with 3rd party parts to dealing with proprietary manufacturing and warranties though.