I found a solar panel rated 9v, 70mA. I want to use it to create a power backup for a 9v, 1A router. Is this possible?
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.
I love this question. don't close it yet guys!!! First thing, let's do the math. 1 amp =1,000 ma.. So if we divide 1,000 by 70 we get 14.28 panels required to run the 1 amp router. That is assuming it isn't cloudy or it is not after sunset and before sunrise. Actually we know the solar would only be effective in charging a back up battery, but I had fun with it. Sorry for my warped sense of humor.