First off, this whole battery removed thing is based on a rumour.
And second, could you please provide a reference to phones that can be traced when turned off. I've never heard of such a thing.
Still looking for an "official" statement, but I'm finding comments like this for now..
Unless you pull the battery you can be logged. All part of the E911 law to make us safer, yaknow.
It depends upon how you define Off.
If you are completely Off; your phone has to re-register and find towers, effectively re-boot and re-initialize. Typically, when a phone is turned off its really set to a sleep mode. So, when you drive, the phone isnt really burning a whole lot of power; but it is picking up new cell towers and dropping other cell towers as they move out of range.
If you want total radio silence; you have to remove the battery - or turn the phone completely OFF - such that it has to reboot when you re-power it on again.