Erratic windspeed

Hi
I have been getting some ridiculous windspeeds (gusts 152 kts) on my Oregon wmr300 which I think is caused when long periods of dull weather have reduced the solar charge resulting in low battery volts. As most anemometers work in much the same way I wonder if others have found similar effects. I don’t think local eddies and turbulence could account for that sort of speed.
Regards
Alan