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Thread: Solar laptop and mobile charger

  1. #1
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    Default Solar laptop and mobile charger

    I've seen some backpack chargers on the market. What do you think of them? I'm new to solar energy. What's the best place to go to learn more about solar energy and how it works with small electronic devices?

    Thanks,

    Mark S.

  2. #2
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    Default

    Quote Originally Posted by mtschus View Post
    I've seen some backpack chargers on the market. What do you think of them? I'm new to solar energy. What's the best place to go to learn more about solar energy and how it works with small electronic devices?

    Thanks,

    Mark S.
    The problem is that solar panels are small and need to be aimed at the sun to produce - the farther they are off perpendicular to the sun the less power produced. Not often one is always walking directly away from the sun.

  3. #3
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    Default Voltage support is the test

    Quote Originally Posted by mtschus View Post
    I've seen some backpack chargers on the market. What do you think of them? I'm new to solar energy. What's the best place to go to learn more about solar energy and how it works with small electronic devices?

    Thanks,

    Mark S.
    You ask a good question, and you are correct in being cautious about chargers you see on the market.
    The biggest issues with powering laptops from solar are:
    1. adequate solar power production to support reasonable laptop run times
    2. sufficient power storage to support reasonable laptop daily run times
    3. voltage support for the specific laptop you are using
    4. connectors... you ultimately need to connect your laptop to the system!

    One other sidebar note: DO NOT use an AC inverter if you can avoid it. An AC inverter (the box that creates a household AC plug from a 12V battery or your car) will waste anywhere from 15-30% of your battery power in the process of creating AC power which your laptop will ultimately convert back to DC for its own use anyway. When you are in the power desert, you don't go wasting/spilling electrons!
    Plus, most people nowadays want to use a lithium battery pack with their solar equipment in order to minimize weight, and aside from the Goal Zero Sherpa models, lithium battery packs WILL NOT support AC inverters.

    So, back to the task at hand...
    1. Figure out how many hours a day you want to run your laptop when you are without power
    for example, I find most people want about an hour each day. As the previous person noted, normal solar maps do not account for the variation in daylight exposure that backpacks see. So, allowing for that, and knowing what most laptops in power safe mode consume, you would need at least a 10W panel to offset an hour of laptop use during summer months (in North America).

    2. Store the power in a battery pack that offers multiple voltage settings, and multiple connector options to support laptops. I recommend looking at the Brunton models (Sustain, Impel), and the Tekkeon MyPower All 3450 models.
    www.bruntonoutdoor.com
    www.tekkeon.com
    Both of these battery systems can support a magsafe connector option for MacBooks (use the Apple airline adaptor with the Bruntons, and a MagSafe connector is available for the Tekkeon batteries).
    The battery pack should be at least 50 Watt-Hours in capacity to properly support the 1-hour run time, and serve a long life.

    Now, that being said, Voltaic Systems just released two backpack products that have everything integrated already...
    Voltaic Fuse 10
    Voltaic Array backpack
    Both of these offer a decent amount of solar power, plus a built-in multi-voltage battery pack that supports laptops & other devices. Voltaic does really good work, and their products are exceptionally well built. www.voltaicsystems.com

    I would provide a direct link to my site, but I will respect the spam rules!

    Lastly, and this might seem strange after writing all this, but I would urge you to consider leaving the laptop at home, and either take a smart phone along instead, or at the most one of the new tablet computers like the iPad. These options use far less power, do as much as most people need, and a power system to support USB and even the 2.1A USB are less expensive and more portable than the full-power laptop-supporting systems that I described above. Only take a laptop if you have specific data-crunching needs that only a laptop can provide.

    I hope all this helps. Please feel free to write, comment, and ask more questions. If you want feedback on any particular product you are considering, let me know.
    Cheers!
    - Graham

  4. #4
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    Default Small electronic devices via solar

    Quote Originally Posted by mtschus View Post
    I've seen some backpack chargers on the market. What do you think of them? I'm new to solar energy. What's the best place to go to learn more about solar energy and how it works with small electronic devices?

    Thanks,

    Mark S.
    OK, I was thinking about another question when I wrote my last reply... sorry... that was more than what was needed.
    Here's the scoop for small electronics...

    iPods, PDA's, and smart phones have on-board batteries of approx 3-8 Watt-Hours, so a solar charger must have at least 3 watts of solar panel power to properly keep up with a daily battery drain on these devices. I am allowing for mobile variation in solar exposure, and for summer months in North America & Europe only (May-Aug).
    I see a lot solar gadgets providing 0.3 or 0.4W panels, and these really are frustrating, and not much more than gimmicks. They will offset only about 15-20% of an iPhone battery for example, and that is even when exposed to the sun religiously all day.
    I would suggest only considering solar charger products that offer at least 1 Watt of solar panel power to avoid disappointment/frustration
    Here are a few examples of good quality, and good power...
    Brunton Restore
    Powerfilm USB+AA charger
    Voltaic Amp
    Voltaic Fuse
    Voltaic solar backpacks

    Most small devices can be connected using USB ports, and most small solar chargers will provide these. Use your device's USB connector cable.
    Apple products, and some others like Blackberries, can be fussy about the USB ports they accept. I try to highlight which ports are 'universal' on my site, but as a rule, if it doesn't specifically state: 'Apple Compatible', it aint. Even if they say 'power your iPod', they may mean mp3 players in general, and this is misleading.

    Cameras are tricky. Small 'point & shoot' cameras can have their batteries charged via small universal USB chargers like this one...
    http://www.modernoutpost.com/shop/ba...ersal-usb.html
    dSLR cameras are usually 7.4V battery packs, and so require a battery system that provides at least 8.4V, so this means going with a full-size power system like I outlined in my last post.

    Hope that this post is more helpful than my last one!
    Cheers,
    - Graham

  5. #5
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    Default Solar for small electronic devices

    Graham,

    Outstanding information!!. Do you have a newsletter I can subscribe to? Are you a solar engineer by trade? Truly, outstanding information.

    So in your opinion, is current research working to improve the solar panel efficiency? Is the focus more on battery improvements? Probably both. Do you see any breakthrough coming on the horizon? Are there better materials coming out? I'm fascinated by solar power. I'm most interested in the portable solar, but the whole industry is interesting.

    I also wondered how big a solar panel do I need to charge an iphone or other smart phone. Really, how small could it be? Are there brands that are more efficient per square in or cm? How small can the battery pack be?

    Thanks for your help,

    Mark Schuler

  6. #6
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    Default I Built a solar charger for my sony PDA back in the day.

    I built a solar charger for my sony PDA and Cell phone back in the day using scrap solar cells. It worked fine for small devices. I would imagine the commercially available products would be more than adequate for charging small electronic devices since the efficiencies have gone up.

  7. #7
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    Default

    Quote Originally Posted by mtschus View Post
    Graham, Outstanding information!!. Do you have a newsletter I can subscribe to? Are you a solar engineer by trade? Truly, outstanding information. So in your opinion, is current research working to improve the solar panel efficiency? Is the focus more on battery improvements? Probably both. Do you see any breakthrough coming on the horizon? Are there better materials coming out? I'm fascinated by solar power. I'm most interested in the portable solar, but the whole industry is interesting. I also wondered how big a solar panel do I need to charge an iphone or other smart phone. Really, how small could it be? Are there brands that are more efficient per square in or cm? How small can the battery pack be? Thanks for your help, Mark Schuler
    You would want the solar panel to provide the voltage and current of the device. You can get the voltage fro looking at the battery the device comes with and the current from the name plate on the inside of the device when you remove the battery. area is 8" x "8 inch. depends on the device really.

    Mod note - Welcome to Solar Panel Talk but forget the links
    Last edited by russ; 02-20-2012 at 08:30 AM. Reason: removed link

  8. #8
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    Default my to go pack-2 pieces

    C&G foldable mono panel 42watts 12"x10"x2" folded plugs directly into energizer P18000 power pack:18Ah@5v lithium weights 5.6oz.

    Energizer has three outputs: USB, 105V and 19V. includes a ton of adapters for various devices. works with all of my families devices: cell phone, ipad2 and new iPad, nintendo ds, etc. Energizer has built in charge controller and charging indicator so many different solar panels can plug directly into it. Input voltage is 19V but it does well with my solar panel that typically varies from 14+ to 17+ volts.

    I am not connected with any company or product: retired.

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