Dry laptop while solar charging (5 wks)?

How do you keep a laptop dry while charging it it from solar panels for 5-6 weeks?

Situation: I am a teacher teaching 3 courses online while paddling from Chicago to New Orleans this summer stealth camping along the riverside. I need to be online for several hours every day or two. I will be moving at a swift pace, and my time on shore will not be enough during daylight to charge my laptop.

I need to layout my solar panel while paddling, but still keep my laptop safe and dry.

I have some ideas but not happy with any of them…HELP?

Waterproof connections
I’d suggest laying your waterproof solar panels (I assume you’ve already selected one?) out on the kayak deck, then running the power cord through some sort of waterproof fitting in the deck or a hatch cover to the laptop, which would be safely tucked belowdecks.

You may have to rig up your own supply cord, and perhaps even leave it semi-permanently installed in the boat. Here’s a USB cord with waterproof bulkhead fitting: http://www.amazon.com/L-com-Waterproof-Panel-Mount-Cable/dp/B000AA85BG/ref=pd_bxgy_e_text_b

Good luck!



Several hours per day?
Have you checked to confirm that your solar cell will enable operation of your laptop for several hours per day? This sounds optimistic unless your panel is big and positioned well.

power station
I would have a set of six volts or a small twelve volt battery pack that I kept charged. That way they can charge while the computer is tucked away. Then you can charge the computer at night. It will add some weight but will probably be your best shot. The computer will burn through battery when online. You’ll need a change controller as well.

The power station could be used for phones and bulge pump as well. Just an idea I think it is workable. Pray for sun. I’m not sure the Mississippi will be down by this summer.

Ryan L.

Hardly a realistic goal

– Last Updated: May-04-11 10:33 PM EST –

Laptop consumes 30-40 Watt. In 4 hours it will be 120-160 Watt-hours. Batteries should not be discharged completely, and charging is slower than discharging. For 160 WH you will need 50W solar panel and 105AH 12V deep cycle battery (or 200 AH 6V battery). This is assuming at least 6 hours of good sunshine daily. The numbers are from the sizing chart for off-grid consumers.

50W panel is a huge 30"x20", and 105 AH battery weighs 36-37 lbs.

If you limit laptop use to 1-1.5 hour a day, you might get away with a smaller size panel and lighter battery. Like others noted, it has to be a separate battery - it is easier to waterproof than a laptop. Can't advise on waterproof connectors, sorry.

I dunno

Just a small PV with small battery

– Last Updated: May-05-11 1:41 AM EST –

i.e. equivalent to 12 AH 6V battery. Miracles in physics don't happen. This PV outputs 15W at peak i.e. at noon, no clouds and when sun it at the summer solstice (mid-July? don't remember). On other 364 days it will be less. He won't run laptop directly from PV, so the charge goes into the battery and then out to laptop, with losses.

Fully charged, this battery will provide under 2 hours of power for an average laptop, but it will take all day to charge it in ideal conditions. Not all days are sunny and his conditions are not ideal, so to insure reliable 2 hours of power daily, both PV size and battery capacity should be increased. I estimate PV size should be increased by 50% (1.5 times) and battery capacity 7-8 times, in order to get 2 hours of power. The battery capacity has to be so high because at this point we're past the capacity of usual Li-ion battery, and enter the domain of deep cycle batteries, and those "don't like" being fully discharged, so we should leave a margin for this as well. He might get away with smaller PV and battery, but there is no guarantee.

Btw, it doesn't say it's waterproof.

I did the same thing you did in 2004 paddling the lewis and clark trail from st. louis to the pacific. a trip that took 6 months and i carried a lap top and updated a website for classes and who ever etc. I updated it every couple of days. the techonology has changed a lot since then. I used a satillite phone to send the data to my tent. now days you can access so many cell phone towers and wifi places that you dont need a sat. phone etc.

I had time to recharge. I used two rolling solar panels made by Iowa Thin films and they were awesome. They rolled up like a map. When i was windbound and early sunny days i would “recharge”…i recharged my camera and the phone as well. I bought an extra lap top battery that would allow about 4 hours etc. What REALLY helps, is if you have certain things you are sending the kids that DO NOT need to be written from the river…but WILL be sent from the river…then to type them up before you leave and then cut and paste them as needed. I did this with about 10,000+ excerps from the lewis and clark journals…i.e pretyped what they wrote and saved to my harddrive. When i got to the areas …for example…a month later where they talked about blah blah blad etc, I would paste the journals next to mine…so there was a two hundred year comparison etc. It saved a lot of time and let me tell you something else…after paddling 15 hours upstream against the current the LAST thing i wanted to do was sit in my tent and type/get on the pc etc…so the more you and “pre” do…do it!!!

As far recharging…are you in a kayak or canoe? Make a huge dif. I was in a solo expedition canoe and had plenty of room for a laptop inside a Pelican waterproof case…which once in the case takes up a LOT of room…there would have been no room inside a kayak for that set up unless you mounted it on the deck…

Some suggestions: I talked to some guys paddling the Nile and doing the same thing…they took there pelican case and cut a hole inthe side where the outlet plug would go…the used a rubber cork/plug in which the cord ran through and inserted it into the hole…so that way they could recharge while paddling and have the P-case waterproof. Write me or email me more about ALL this and i can give you more details.

Curious about your trip and plans too.

Another thing…get rid of all the misc. programs on your computer…they suck power. Also there is a way to set the pc to be in …cant remember the exact name or terminology…but its in basic font and minimal everything…ask a pc person…this will save you a lot of power. Also wondering why you dont think you will have enought time to charge power?

Another thing…being on the water all the time you will get dust and dirt everywhere…use electrical tape and cover every plug and outlet hole on you pc to avoid dirt getting into. Also CALL every pharmacy in your area…tell them of you trip and ask them to save you the packets of (cant remember the name)…the the things that keep medicine and mositure from getting into the pills. At the pharm, they are packed in these tiny packets and they toss them out before distributing medicine. I had them save me about 500 packets which lasted about 5 months and they work. I used them in all my electonics stuff. Believe me thing will get damp…and wet if you dont make the precautions etc.

email me for more info and tell me about your trip.



another comment
If you are online for “several” hours day…then you can recharge during those few hours…thats all you would need!

If he is online “several hours” a day…

– Last Updated: May-05-11 4:09 PM EST –

...and doing a serious paddling mileage, his online time would be dusk or after-dusk hours so he won't be able to recharge during those hours :-) ...

Don't want to be negative; 2nd post above this gives good practical info. TAD doable, but he will need all the help he can get. Good power-efficient laptop (netbook?), large size PV panels (larger than that combo unit linked 3 posts above), and as little laptop time as possible, working off-line whenever possible, no random surfing and fooling around etc. Several hours online a day would be difficult - when battery is capable of 4 hours power, it means it requires 10-12 hours to fully charge it from PV. On cloudy days there is almost no charging, so he needs 6-8 hours battery capacity to be able to always have 4 hours of daily power.

No need to apologize, why would I feel the comment is “negative”?

Just know that what I did worked for me etc. YOu mentioned dawn and dusk will be when “online” , then that is perfect for charging…i…e NOT those hours. Between 9am and 3pm( high sun) while he’s paddling will alow plenty of time to recharge. Having the pc in a case AND in the bulkhead will protect from water and allow him to use the panels on the outside of the boat. Yes the shade-clouds play a major roll and so does the weather as far as actually being able to paddle…the wind rules the water as I’m sure you know. Many time I was windbound between 10am and 6pm and did not paddle which allowed for recharging.

Also if hes sending jpg photos…a 9k modem on Sat Phone (if you use that option)…takes for a 475 jpg photo-- 52 seconds to download…which sucks the power. However I didnt have to worry about paying “minutes” since Uridium Sat. Phone paid the bills etc. In the 187 days of paddling…i ended up using 900 minutes of airtime…which was not only uploading time…but also talking to people etc…just to give you a reference point in number of days/output/uploads etc. The total amount of text sent was over 140,000 words and 400+ jpgs. I used a compression software called “Quick-ePics” which compressed 400-700kbaud photos to about 50km with no real loss of quality.

Would love to follow your journey do you have a website? Anyway…if you can use the info to your advantage…go for it!



If you don’t have to live chat. Or even if you do. A smartphone with an external keyboard would probably be sufficient. A micro SD card would serve as memory for documents. The Adobe readers work great as well. I pretty much only use my phone as my computer. It is weird at first but you get used to it. It will use less power and is way easier to charge. Plus you’ll have service a lot.

Ryan L.

with a folding keyboard is an excellent idea. I don’t have one so can’t really comment, but I’m sure it consumes MUCH less power than a laptop. More difficult to work because of a small screen, but much more energy-efficient.

iPad too…slightly bigger easier to type of big keyboard. Can download mega photos and edit it. Has Wifi and you could pick up wifi signal along the river as any town.

Thank you so much
This is great advice.

A little more info. I am in a canoe, with my dog. At this point I am either going to:

-put the panel in a clear seal line bag, along with the computer

-or put the netbook in a pelican case with a cord plug resealed by silicone.

This is great advice

thanks all


I would not put the panel in a bag. By their nature they can handle the weather. The bag could block light and cause heat to build up which will effect efficiency.

Ryan L.

ditto - no bag

– Last Updated: May-10-11 11:43 AM EST –

PV panels get hot because they're black, and oriented perpendicular to the sun. Their efficiency drops by about 1% per degree above 110 or so. They need air circulation for cooling, so don't put your panel in a bag. If possible, don't even put it directly on top of a bag or other gear. You want a few inches of air space behind the panel to let it cool.

If you're looking to optimize output, I'd make a mount for your panel on one of the thwarts. If the panel isn't too big, some loc-line would make a swell mount for about $25. Just take a minute to install.


If the panel is heavier, you'll need to come up with something a little more robust.

actually, iPad is geat idea
iPad is a great idea, not just because it is a good product. But because it uses flash based memory, rather than a rotating disk hard drive, it uses a lot less power (so has a smaller battery, which would require less time to recharge). There are other options out there that also use flash based memory, such as the new Apple laptop and some of the windows-based netbooks.

Is there any kind of small generator turbine that would utilize the energy of the passing water while paddling? Or even the river current when camping? Might be more efficient than a solar panel…

There are turbines that work underwater. They are mostly designed for deep fast moving creeks. I have seen some used on barges but there is now way it would work on a canoe. It would create way too much drag. I don’t know if it would work at night. It would depend on how much current you could find near shore.

I always wanted to use micro wind turbines. One about half the size of a sail boat rig. Your boat would have to have a rudder.

Ryan L.