Solar panel: Current-related question
It depends on how much you plan on using the solar backup.  If your battery can handle the router for a few hours, and it will only have to power it once every 2 or 3 months for an hour or two, yes, it should be fine.  If your electricity goes out for long periods of time, or if it goes out often, I'd say no... however, you can always string them up in parallel, increasing the amperage output.