Electronic key battery life

I just received my Prius V. On page 64 of the Owner's Manual there's a warning of "serious deterioration" in the key battery life if it is kept within three feet of a cell phone or various other transmitting devices. Does anyone know how significant this issue is? If I keep the key in my left pocket and my iPhone in my right pocket (less than three feet between the two) will I notice significantly reduced battery life? The manual says 1-2 years is standard, it would be annoying if the battery life dropped into just months because of the proximity of my cell phone. Thank you.

Not sure about the 2010, but with my 2004, I changed the battery about every two years. Cell phone on my belt, key in my right pocket.

I've been doing that (key in one pocket, cell phone in the other)since 2005 and my key still works fine. It doesn't have super range but then again, it never really did.

The batteries are so cheap I am not concerned. They use a standard watch battery.

Everythng will have to live in my pocketbook and play nicely together inches apart. I'll keep track of battery life...as soon as I get a car key.

Right pocket and left pocket works fine. Don't keep them in the same pocket.

Tom

I would keep the cell phone in the trunk while driving just in case this is true.