<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi all,<div><br></div><div>As always, i can offer no practical fieldwork advice, but...</div><div><br></div><div>Our company provides small mobile internet connected computer labs in a suitcase (or, rather, pelican case) to a number of schools in off-grid parts of Uganda. We fit 11 netbooks with 9 cell batteries and a single loom charger. Most netbooks are designed to draw 19V, but we have no problem at all fitting the loom directly to a 12V battery and providing DC power. With this lab-in-a-case, we are able to provide fully internet-connected(3G/gprs/edge/sat (with a SPOT (<a href="http://www.findmespot.com/en/index.php?cid=116">http://www.findmespot.com/en/index.php?cid=116</a>)) to places that have no power. The system is able to be used for about 5 hours without a charge, but a whole day oif trickle charging from solar. Whilst this solution works for getting everything charged at a base station where solar panels can be permanently fixed, there are also a number of really good portable options. </div><div><br></div><div>Keeping in mind that the netbooks will run fine on 12V DC (as will small desktop PCs like the Eee Box which can be fitted with a DC LCD monitor), it is possible to rig a 12V folding solar panel directly to the charger of the netbook. Suntech make small folding 60W 12V panels but they still weigh about 15kg - not great for lugging around. ALternatively, and much better if weight is a concern, is the 20W solar-charging laptop bag (<a href="http://www.multipoweredproducts.com.au/products/Voltaic-Generator-%2d-Solar-Laptop-Charger-Bag.html">http://www.multipoweredproducts.com.au/products/Voltaic-Generator-%252d-Solar-Laptop-Charger-Bag.html</a>). This bag has batteries which will bring your netbook up to a full charge in a day, provided you get about 5 hours of sunlight. It's probably not going to be enough to charge a full-sized laptop though. It also has outputs for you to connect 5V USB devices and car-plug options. This means you can plug in a caravan/car/camping style lamp into the case at night and give yourself plenty of power. </div><div><br></div><div>Cheers,</div><div>Xavier</div><div><br><div><div>On 27/01/2011, at 4:06 AM, Jeremy Hammond wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Hi All,<br><br>I am pretty much in agreement with Tom and have being successfully doing a<br>similar setup for the past 3 years in Vanuatu. I also buy lead acid<br>battery in-situ but am considering getting a solar-specific one this year<br>if I can find it in Port Vila. I'll just add 3 points.<br><br>1. Buy a universal battery charger. They are great and means you can<br>really cut down on the amount of chargers you have to take (I.e.<br>phone/Camera/AA/video/AAA/USB are all doable with mine). Here is one<br><a href="http://www.solartechnology.co.uk/shop/camcaddy-cc1005.htm">http://www.solartechnology.co.uk/shop/camcaddy-cc1005.htm</a> but there are<br>different brands/models. You can buy them at most camera stores. I just<br>have two of these for all my charging needs (plus my laptop charger of<br>course).<br><br>2. Consider getting solid panels. If you have easy enough access to your<br>fieldsite and have a long term relationship with them then it is an easy<br>process to take it there and set it up on a roof etc. I usually take a<br>solid 50W panel with me each time I go so that now I have around 150W<br>which should be above 200W this coming year. They are super strong, and<br>great long term value. Plus now I leave them there setup with LEDs on the<br>battery so that people there can use the light at night, even when I'm not<br>there.<br><br>3. While tom suggested the "workman's" light and they are good, if you are<br>electrically handy then making your own LED setup is really inexpensive<br>and easy. There are some great yellow ones that are good for<br>reading/working by as well. On that note as Tom said, test your setup but<br>also understand how it works. Get a friend who knows something about<br>electronics to explain it to you and when things go wrong, you will be in<br>a much better position to fix it.<br><br>Jeremy<br><br><br>-------------------------------<br>Jeremy Hammond<br>Syntax, Typology and Information Structure Group<br>Max Planck Institute for Psycholinguistics<br>P: +31-24-3521171<br>E: <a href="mailto:Jeremy.Hammond@mpi.nl">Jeremy.Hammond@mpi.nl</a><br>W: <a href="http://www.mpi.nl/people/hammond-jeremy">http://www.mpi.nl/people/hammond-jeremy</a><br><br><br><br><br><br><br><br>On 26/01/11 7:27 AM, "Tom Honeyman" <<a href="mailto:t.honeyman@gmail.com">t.honeyman@gmail.com</a>> wrote:<br><br><blockquote type="cite">Hi Jeff,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Despite the negative "reality check" at the end of the paper Pat<br></blockquote><blockquote type="cite">mentions (thanks Pat!, also the paper supersedes the blog posts, but<br></blockquote><blockquote type="cite">thanks Peter!), I am now quite happily using solar power for fieldwork<br></blockquote><blockquote type="cite">in Papua New Guinea.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">My current setup (well actually I've dropped/genericised/forgotten a<br></blockquote><blockquote type="cite">few items to simplify!):<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">1 low power netbook (they're all almost exactly the same)<br></blockquote><blockquote type="cite">2x DC adapter for netbook, but also adapters to charge USB devices,<br></blockquote><blockquote type="cite">mobile phones etc also very good<br></blockquote><blockquote type="cite">2x Li-Ion battery pack chargers (for camera, video camera etc... can<br></blockquote><blockquote type="cite">be very handy)<br></blockquote><blockquote type="cite">1x DC-DC adapter with multiple plugs (very handy for powering all<br></blockquote><blockquote type="cite">sorts of things if you know what you're doing)<br></blockquote><blockquote type="cite">DC plug adaptors (so I can plug in many things at once)<br></blockquote><blockquote type="cite">50W foldable solar panel<br></blockquote><blockquote type="cite">charge regulator with load cut-off<br></blockquote><blockquote type="cite">10x AA NiMH AA batteries<br></blockquote><blockquote type="cite">8x AA NiMH AAA batteries<br></blockquote><blockquote type="cite">1x AA/AAA battery charger (charges 10 batteries at once, each<br></blockquote><blockquote type="cite">individually)<br></blockquote><blockquote type="cite">1x AA/AAA battery charger (charges 4 batteries in pairs - this can be<br></blockquote><blockquote type="cite">a pain if you have a device that uses 3 batteries!)<br></blockquote><blockquote type="cite">Head torch and mag-lite - make sure they work with rechargeables!<br></blockquote><blockquote type="cite">Often they don't work well with them.<br></blockquote><blockquote type="cite">12v/DC workman's light, fluro or LED based, low power consumption<br></blockquote><blockquote type="cite">(these are really good for a lot of light!)<br></blockquote><blockquote type="cite">All the regular equipment otherwise (recorders, speakers, mike,<br></blockquote><blockquote type="cite">cameras, etc), but make sure they work well with rechargeables).<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">And then I also pack the following for fixing stuff (but only if you<br></blockquote><blockquote type="cite">know what you're doing):<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">fuses, glass and blade with several spares for each device that has one<br></blockquote><blockquote type="cite">pack of alligator clip wires<br></blockquote><blockquote type="cite">Gaffer tape (often available in country)<br></blockquote><blockquote type="cite">digital multi-meter<br></blockquote><blockquote type="cite">pocket knife<br></blockquote><blockquote type="cite">jeweller's screw driver set<br></blockquote><blockquote type="cite">super glue (often available in country)<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I tend to buy a (preferably deep cycle) lead acid battery in country.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">This let me work for a few hours a day on the laptop, use torches/<br></blockquote><blockquote type="cite">flashlights at night, and put on a "movie night" once a week. Every<br></blockquote><blockquote type="cite">now and then an activity might come along (like a big recording<br></blockquote><blockquote type="cite">session, or very rainy weather, or on one occasion my roof blowing<br></blockquote><blockquote type="cite">off!), which would drain the battery too much. Then I'd have a day or<br></blockquote><blockquote type="cite">two not using the laptop (far and away the most power hungry).<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"> 4 things I'd recommend:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">(a) check _everything_ beforehand. There are many "single points of<br></blockquote><blockquote type="cite">failure" in a solar setup. That's why its good to have backups, or<br></blockquote><blockquote type="cite">multiple ways of achieving the same thing.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">(b) get a charge regulator with a load cut off. This magical box will:<br></blockquote><blockquote type="cite"> - ensure that the battery is charged properly, dropping the power as<br></blockquote><blockquote type="cite">it approaches a full charge and cutting the power entirely when the<br></blockquote><blockquote type="cite">battery is full<br></blockquote><blockquote type="cite"> - stop power flowing back into the panel at night (this is often<br></blockquote><blockquote type="cite">redundant depending on the panel)<br></blockquote><blockquote type="cite"> - cut the power to your devices when the battery is too low<br></blockquote><blockquote type="cite">Basically this will let you safely run your equipment, but it'll<br></blockquote><blockquote type="cite">ensure that the battery doesn't fail because you've drained it too<br></blockquote><blockquote type="cite">much... this is something that is _very_ easy to do. If you know what<br></blockquote><blockquote type="cite">you're doing then you can drop this, but you'll spend more time<br></blockquote><blockquote type="cite">managing your power setup and less doing work.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">(c) try to eliminate using AC power. This is costly. I guarantee that<br></blockquote><blockquote type="cite">you will not have enough power to do all the things that you'd like to<br></blockquote><blockquote type="cite">do. So this means do not use "wall adapter" plug equipment, use "car<br></blockquote><blockquote type="cite">adapters" for all of your equipment. The DC adapters for charging a<br></blockquote><blockquote type="cite">laptop can often power other equipment. The DC-DC adapter is extremely<br></blockquote><blockquote type="cite">useful for powering low power equipment. Having these flexible, multi-<br></blockquote><blockquote type="cite">plug adaptors can be very useful for unexpected scenarios like<br></blockquote><blockquote type="cite">powering a cassette recorder you've borrowed because your audio<br></blockquote><blockquote type="cite">equipment fell in the river. Or powering your recorder directly<br></blockquote><blockquote type="cite">because your batteries or battery chargers have failed for some reason.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">(d) check that the AA/AAA powered equipment works, and works well with<br></blockquote><blockquote type="cite">rechargeable batteries. Rechargeables operate at a lower voltage than<br></blockquote><blockquote type="cite">Alkaline batteries. A lot of equipment is designed for use with<br></blockquote><blockquote type="cite">Alkaline batteries, and even though initially they may work fine,<br></blockquote><blockquote type="cite">later in the field you may discover that they have a (seemingly) short<br></blockquote><blockquote type="cite">life. Digital cameras often are designed to work with rechargeables<br></blockquote><blockquote type="cite">these days (sometimes they last longer with rechargeables), but<br></blockquote><blockquote type="cite">torches/flashlights for instance are often not.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Hope this helps,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Tom<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On 26/01/2011, at 3:48 PM, Patrick Hall wrote:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><blockquote type="cite">Hi,<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Honeyman also coauthored a paper with Laura Robinson on this topic in<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">LD&C which might be of use:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Honeyman, Tom & Laura C. Robinson. 2007. Solar power for the digital<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">fieldworker. Language Documentation & Conservation 1(1): 17-27.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">It's available online:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><a href="http://hdl.handle.net/10125/1722">http://hdl.handle.net/10125/1722</a><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">cheers,<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Pat<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><br></div></blockquote></div><br></div></body></html>