Well, I never have "low transmitter battery" problems with my cabled VP2, and the fan runs 24/7 with AC power, and the rain bucket heater runs all winter.
Is your cabled VP 2 easy to run power to? Did you have to install a special line to it?
Mine will be on the roof. No power up there.
I did lose some data this past winter on frozen precip.
"Easy" is a very undefined term. I didn't have much trouble running wires out through the basement wall, and then underground (where necessary), and up the pole. In a previous location, I didn't have much trouble running wires up through the wall and through the roof (with a pipe), across the roof, and up the pole. But your mileage may vary, depending on lots of factors.
All of the wiring to the VP2 is "low voltage", so I don't need power on the roof (or outside the house). The transformer that powers the rain bucket heater, and the one that powers the FARS, are in the basement. With the wireless VP2, you could do the same thing (there's a DC power input connection on the board in the ISS).