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?

  • 2
    You'd need to use a battery, which is pretty much necessary with solar anyways. This is probably better asked over at electronics.stackexchange.com
    – gregmac
    Feb 8 '11 at 18:32
  • Batteries are not necessary with solar unless you want to run things while the grid is down. If you're just looking to save money, a typical home/business owner does not need or even want to get batteries. Batteries are expensive and do not pay for themselves unless the devices/appliances they can keep running while the grid is down are critical in nature.
    – Michael
    Feb 9 '11 at 0:09
  • @Michael Right, but the OP's question was to "create a backup", which surely means "when the grid is down", right?
    – Phrogz
    Feb 9 '11 at 5:50
  • He should have said "a solar backup." I'm not upset about it at all... just making sure that it's not ambiguous so that people new to the topic do not get confused.
    – Michael
    Feb 9 '11 at 6:29

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.

  • @shirlock homes- Can I get the panel to charge a battery when its sunny and then use the battery to power the router when I need it ?
    – user1649
    Feb 9 '11 at 2:54
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    @infoquad Yes... that was what I was implying with my answer. A tiny solar panel like that won't be able to run the router indefinitely, but if it can store its output in a battery, and the battery can run the router for hours, then yes... such a setup will run the router for hours. Given enough time to recharge (a few days,) it can run the router, once again, for hours. A good analogy would be a water heater. Can your water heater keep up with your shower? No. But if you have some storage, you can take a shower without ever getting cold water.
    – Michael
    Feb 9 '11 at 3:26
  • 1
    Also, the router is not necessarily drawing 1A all the time, that is the max load (and actually, I'd guess it's really a 1A transformer, which could be bigger than the router actually needs). Again, another reason why batteries are nice - if you match panels to a bit higher than the true average draw, the batteries will handle the occasional higher bursts. Of course, batteries also help to keep it running at night..
    – gregmac
    Feb 9 '11 at 3:30
  • @Micheal- Thanks.Could you please elaborate on how I could set this up?
    – user1649
    Feb 9 '11 at 3:36
  • 1
    @infoquad If you want information on how to set it up, either ask another question or edit your question to ask this. So far you've asked "is this possible?"
    – Phrogz
    Feb 9 '11 at 5:52

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