Anyone have any idea as to the life expectancy of the controller battery?

You'll likely either stop flying or sell your Mavic before the battery needs to be replaced.

Many thanks. Hope your answer was not based on my age.

Paul_ Posted at 2018-10-27 11:10
Many thanks. Hope your answer was not based on my age.

Hi there. Thanks for reaching DJI Forum. In addition to your query, The built-in battery has a capacity of 3950 mAh and a maximum run time of 2 hours and 15 minutes. If you have further question, please don't hesitate to contact us. We will do our best to help you out. Thank you.

Probably  2-3 years (depends on how frequently  charged  or dischared) . life and performance of the battery will natrually degraded.  similar  like the mobile phones battery . either you can replace whole rc or  by then  you wil buy a new model