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 Change a Prius Key Battery or Purchase a Smart Key - AxleAddict
Amazon.com: Key Fob Battery Replacement Compatible with Toyota Prius (2009-2022 Toyota Prius & Prius Prime) (2010-2016 Prius) : Automotive