Key battery low." Oh great, what's that going to cost me? $400 and can only be done at the dealership? Oh, you can open the fob with the key itself and replace
How to Replace a 2016 Prius Key Fob/Remote Battery - YouTube
Toyota Prius Questions - 2010 Toyota Prius with a dead key fab no battery to change just green ... - CarGurus
How To Unlock and Start Your Toyota Prius With a Dead Key Fob | Torque News