Solar Powered WiFi Repeater

For all those times you need to broadcast your own access point where there’s no outlet [Larry] shows us how to make a solar-powered hotspot. He started by slapping a solar panel on the lid of a cigar box and attaching it to five rechargeable AA batteries inside. These power the mainboard from a router which is the perfect size to friction fit in the opening. It has been flashed with a copy of DD-WRT, and set to scan for open WiFi connections. When it finds one it connects and rebroadcasts its own WiFi signal to the surrounding area. He leaves it in the back window of his car and uses it to get on the net during lunch.

43 thoughts on “Solar Powered WiFi Repeater

  1. Neat! I’d be interested to know the physical lifespan the batteries through that kind of charging setup (overcharge, overvoltage, etc?) and then how many hours it gets from that charge.
    I could use something like this out at my buddy’s farm to extend his house’s wireless signal out across the fields!

    1. and an omnidirectional antenna too, we could use these around starbucks and mcdonalds’ to cover the entire planet with free wifi. that is, if starbucks doesn’t cover the planet with starbucks’ first.

  2. The batteries were my first thought as well. Without a charging circuit you’d have to be careful where you leave that thing sitting around (hopefully in the dark most of the time!).

  3. I bought the DD-WRT flash for a router, and because I asked about the ability to use it to aggregate bandwidth, I was banned from the site.

    I was able to hook up 3 yagi type antennas to some round DTV dishes, and could pick up literally hundreds of open wifi networks in my neighborhood. The thought of being able to connect to a few dozen or so and aggregate the bandwidth to a single wireless N repeater/router that I (or anyone else in range) could pull 300MB internet was a great one, until I asked about it!

  4. Nice.

    It sure would be sweet if, when detailing one’s own hacks, you would tell us the type of router, how many amps it draws at 6 volts, The type of batteries (NiCad for a higher non-regulated charge rate or NiMH for the capacity or lack of cadmium?), the rating of those batteries, and the specs of the solar panel.

    A parts list with prices broken out wouldn’t hurt either.

    Otherwise this is just a nice post with a picture and another fscking youtube video.

  5. lifepo4 cells would also work, those have an effectively unlimited cycle life if charged/discharged correctly.
    ideal format is a main/backup pack with a switch to ensure that the energy is taken from one at a time, with a dual charging circuit to charge both packs as needed when light is available.

    some circuitry to reduce power consumption if both batteries are near empty wouldn’t hurt..

  6. This isn’t a true repeater, :/. This is really just a bridge of a wireless bridge and an access point(/router). Still, fairly neat and easier to implement than a hardware level repeater.

    On the battery notion, I don’t think there is much of an issue in the way of charging/discharging. NiMH is fairly forgiving, and with the electronics in the AP, I doubt he’ll run into issues with over discharge. With the solar panel, I doubt he run into issues with overcurrent during charging, and due to the periodic nature of the sun, I doubt he’ll run into overcharging issues either.

  7. I didn’t know ddwrt able to do this. Wouldn’t you rather call this a solar powered WDS endpoint instead of repeater?

    A repeater doesn’t understand the protocols and works in layer2.

    BTW If you take the time to build something like this don’t use some crap cigar box but make a waterproof design what you can leave outside.

  8. I could have accepted such a simple reply from the DD-WRT site.

    Unfortunately I got shut out.

    Anyways, I actually left the antenna array in the attic of my old house (still intact minus the router).

    This is a cool hack, but with cell phones doubling as hotspots now it will not be a necessity for very long!

  9. Dude, just get a data plan. The cost of parts alone is a month or two of Virgin pay as you go data usb dongle thingee.

    Other than that, if he’s using wifi during his lunch break then he has a device with wifi to browse with. Run the same script used on the router to find open APs on your browsing device. There, I just saved you 40 bucks. You can thank me later.

  10. @cknopp

    I doubt they banned you for asking that. Anyways you can’t really aggregate different connections but you can choose which one to go out on or build a failover link, if 1 wifi network goes out it autoroutes you through the other one.

    Of course when that happens all your existing outgoing connections will be dropped.

  11. @cknopp

    I assume you want the bandwidth for file downloads, right? If we are talking about bittorrent, it would be trivial to setup N number of routers running dd-wrt with a bittorrent client. They would all connect to N of your neighbors’ APs. Then when you want to download something, a script on your computer will break up the torrent into N equal chunks and give each router a portion to download with no overlap. When a router finishes downloading its portion, it would upload it to your computer. If you want to use this for other protocols (ftp, http,…etc) you’ll need a central router to split up the tasks but most likely you won’t be able to get it to work for all file downloads. For surfing the web, the central router can download the html file, and then break up the various objects in the page to be downloaded by the other routers. So your computer would actually be surfing the cache of the central router. It would work best if the central router continuously downloaded all pages and links X number of levels deep ahead of you as you surf. This wouldn’t be that great for real time internet events (ebay auctions, stock quotes…etc).

    Having said that, this is probably a quick way to get jail time and get banned from owning technology. Stealing your neighbor’s internet is bad enough. You want to steal from multiple neighbors, and then most likely use their connection to do something even more illegal.

  12. Xeracy, Wifi range and speed make that sort of improbable. With WDS, bandwidth halves at every repeater. So 54g becomes 27, becomes 13.5, becomes less than b at 6.75. And this is a perfect theoretical environment without interference. Plus lag/Latency.

    Wifi Client/Wifi AP bridge is just as bad or worse.

    That said, He’d be better off with like a fonera.

  13. I agree this project is very devoid of details.

    It’s cool and all, but the particulars are always a good read.
    It also opens up the floor for discussions more easily.

    Still a cool piece though.

  14. Yeah a light router like a fonera is a good choice.

    Ive already done this witha medium folding panel, directly to the router with no batteries. Works great in direct sunlight ;)
    I had wired a usb cable to the router, to power it off any usb power source aa well.

    Never posted as it was never packaged up nice.

  15. Anyone know what the DD-WRT script is which he’s using that does this: “and set to scan for open WiFi connections. When it finds one it connects and rebroadcasts its own WiFi signal to the surrounding area.”

  16. Hey, I always leave a wireless hotspot open to my neighborhood. I have an old linksys WRT54G (with the power turned up using DD-WRT and some nice antennas so I cover a large area) I limit bandwidth but otherwise leave it open (my internal network has it’s own security) I named it “OpenFree” wouldn’t it be nice if everyone did this?

    A quick scan of my neighborhood(using a coffee can directional ant) gives me about 13 open unsecured networks anyway.

    It’s not my job to be a net policeman, this isn’t Nazi Germany or Stalins USSR.

    I also allow people to walk down my sidewalk in front of my house. There’s even a catwalk running through my yard to the street behind me that is used mostly by children going to school and little old ladies walking to the pharmacy it cut’s through the entire neighborhood and was built in 1941 when people weren’t so paranoid.

    I hate this “we have to watch everyone to make sure they aren’t doing anything illegal” idea that seems to have spread like cancer through our society. If I choose not to lock my door (I don’t lock my front door by the way and in 40 years I have never had to) thats my choice.

    If someone decides to be a criminal that’s their choice and they take the consequences. The very idea that I have to secure everything or somehow be liable for others is absurd and DISTURBING, it’s the opposite of living in a FREE and OPEN society and I will gladly fight for EVERYONES right to not be a PARANOID SOCIOPATH.

    It’s this odd notion that’s driving the new ACTA treaty that threatens to stifle the free flow of information for the dubious notion that law enforcement should have the right to monitor everything you do at any time for any reason without due process(roll over Fourth amendment your dead) I urge all free people to push this direction and not give in to those who wish to alienate us from our neighbors and control the flow of ideas.

    Nuf ranting.

  17. @Trollicious

    Unfortunately, in the case of leaving your door unlocked (which I do usually as well) is that you will likely pay the consequences if you are robbed, not the criminal.

    Another example would be your car…if the door wasn’t locked, in many areas the Police won’t even investigate a theft.

    Sadly, thievery is a fact of life and has been for as long as humans have been forming societies.

  18. Ethical considerations aside—I took my DD-WRT enabled router after seeing this and stuck it in my car with a 12-v lighter plug. Also, I threw my Linksys external antenna mount on top of the car for more antenna gain. Today, I used it at work and stayed connected to an internet hotspot almost 300 feet from my parking lot. SCORE!

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