My weather station went down after years of service.

Changed out the THREE rechargeble alkaline batteries and it ran for a
week but now dead again.

Probably the solar panel not recharging the batteries.

Pain to get down.

Need suggestion on finding a replacement solar panel.

I can just stick on the outside of the weather station rather than
tearing into the unit.

Need an all weather (Southern California, no snow or ice) solar panel.

What might the open circuit voltage of the solar panel be ?

Links please.