After 5 years and 50k miles, my 2009 Prius OEM tires are reaching the tire thread wear marks and I will need to change all soon. Since the tires will be removed from the wheels, Is it a good idea or even possible to change TPMS batteries at this time? I plan to buy at tirerack and get it installed at a local shop. By the way I liked the OEM Goodyear. It drove well in summer, rain and heavy snows (I am in Chicago area) and lasted reasonable well.
When the batteries do run down, you will have to change the sensors. I have not heard of more than 1 or 2 going bad, even on cars older than yours, so I don't think its anything to worry about right now.
I'd be inclined to leave them be, and if the batteries die, continue to leave them be, for the duration of the new tire's time on the rim. And the next time you change tires, maybe still leave them be: TPMS is a great idea, but way too much $ and dealer intervention required in the Toyota iteration, my 2 cents.
I just replaced mine on two tires. The battery is sealed and you can't open it to replace it. I replaced since the TPMS sign was showing constantly and I couldn't ignore it any longer. Buy online or from a junk yard otherwise it's pricey.
