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Solar Chargers

Discussion in 'Android Devices' started by yzingerr, Aug 12, 2010.

  1. yzingerr

    yzingerr Well-Known Member
    Thread Starter

    Anyone have any luck with solar chargers for the Droid?
    I bought some cheapo ebay thing, and my phone refuses to charge with it... BIG surprise! :rolleyes:

  2. FrayAdjacent

    FrayAdjacent Android Enthusiast

    I haven't checked any, but I'd think most won't provide a constant current.

    I did see a project in Popular Mechanics (IIRC) that used a solar panel to charge a 12v battery, with a 12v cigarette lighter socket connected so you could charge your phone from there.
  3. Gladiator341

    Gladiator341 Lurker

    I have a solio solar charger it works good in an emergency but it can not hold a very big charge so it needs sunlight while charging the phone to fully charge it, and takes a few hours if the battery is low.
    sithman93 likes this.
  4. shadowdude777

    shadowdude777 Android Expert

    Yeah. And the problem with an inconsistent current is that the damn screen turns on every time you unplug it so you'd probably keep losing what you just charged back up if it's really intermittent.

    And that's an interesting project, but assuming you're referring to a 12V lead-acid battery, that's hardly portable. What a workout to keep that thing in your bag! :p
  5. yzingerr

    yzingerr Well-Known Member
    Thread Starter

    Yeah, I should mention that it must be light and portable
    sithman93 likes this.
  6. DarcMasta

    DarcMasta Newbie

    I remember that I had to build one for a Solar Energy Final a few years back. Although it looked rickety, it somehow was able to charge the battery. Not amazingly but from 15%->40%. Solar Chargers are a great concept, but I feel they dont have enough funding yet =(, wish it did cause then I can take advantage of this sunny weather......and not complain about how the A/C isn't working.
    {at least then ill be hot and have a charged phone =-p}
  7. Shootr

    Shootr Well-Known Member

  8. yzingerr

    yzingerr Well-Known Member
    Thread Starter

    Im outdoors all of the time without a power receptacle to plug into (though I usually have plenty of sunshine!)
    especially when camping!
  9. FrayAdjacent

    FrayAdjacent Android Enthusiast

    It's definitely not portable. The panel it used was one of those 3'x1' panels putting out about 45W, IIRC. It also had an optional inverter to power 110VAC devices. It ran off of one of those small 12v lead acid batteries and had a charge regulator. You could add multiple batteries in parallel for more juice.

    It would be a home-based thing to charge your phone and other small devices from solar power.
  10. FrayAdjacent

    FrayAdjacent Android Enthusiast

    When photovoltaic panels are available for $1/watt or less (some up and coming technologies should be closer to $0.10/watt) it will be more economically feasible to set up a home power system. I'd like a system that can get 6-10kW peak so I can run everything in my house and have spare power to charge a battery bank.
  11. Slodog

    Slodog Lurker

    I just got a Brunton Explorer solar charger and it will not charge my Droid. From what I can gather it puts out 1000aM at 5v and this seems to be pretty standard with the other chargers I've seen. Is this just not enough juice or is there something I'm missing.
  12. shadowdude777

    shadowdude777 Android Expert

    The official Droid wall charger is 850mA@5V so 1000mA@5V should definitely suffice. But yeah, this is what I feared about solar chargers, the fact that they just don't put out continuous power.

    I'm not quite sure about this, it's just speculation, but perhaps you could put a supercapacitor (maybe around 1F@5V) in series with the panel.
  13. skunkpbguy

    skunkpbguy Android Enthusiast

    I'm still looking for the inertial based chargers that have been promised.. anyone found a source for these?
  14. shadowdude777

    shadowdude777 Android Expert

    You mean like a "shake-to-charge" concept like they use in some flashlights? It's a terrible idea. It doesn't help in the slightest.

    Circuit - Modified Shake to Charge Flashlight - page 2

    That's the circuit. You would replace the white LED with a USB port, basically. But if you go to page 3 you can see why this is a terrible idea.
  15. skunkpbguy

    skunkpbguy Android Enthusiast

    The versions I'd read about were vastly improved over the flashlights, but none of the cell chargers have ever made it to market.. at least I cannot find them listed for sale.
    The main purpose of my search is I walk constantly at my job and if generating a 'free' charge is possible, I'm all about doing it while keeping my phone in my pocket.
  16. yzingerr

    yzingerr Well-Known Member
    Thread Starter

  17. shadowdude777

    shadowdude777 Android Expert

    I call BS. The Droid has a 4.8Wh battery. They're saying you get about 2.4Wh in 20 minutes? That's a claim of 7.2W of power from a Droid-sized solar panel.

    In comparison, this 5x5" solar panel square generates 1.25W.

    Unless they're using some magical, non-silicon based technology, it's all lies. But then they must be using something magical to bump up the price on an el cheapo solar cell with a MicroUSB plug attached to it to $40. It couldn't be a marketing scheme.

    You'll need to carry around a square foot or so of solar panels to charge your phone at their claimed speeds. Solar panels just do not work for mobile charging; they work if you have an array on your roof, not if you have one sewn into your backpack.
  18. takeshi

    takeshi Android Expert

Motorola Droid Forum

The Motorola Droid release date was November 2009. Features and Specs include a 3.7" inch screen, 5MP camera, 256GB RAM, processor, and 1400mAh battery.

November 2009
Release Date

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