Solar Laptop Rechargers

[Kitsune]

This whole post is likely wishful thinking or just curiosity at this stage......I also do so some camping so it might sometimes in the future be worth looking at though

I notice that on the web that there are some laptop rechargers which are solar powered. What I am kind of curious about is if anyone has ever used any. How powerful a one do you need to actually run a laptop?

[Starglider]

For a ballpark figure, average laptop uses about 20 watts idle and 40 watts under load, not including charging the battery. Desktop replacements will use double that, netbooks maybe half that. A 40 watt solar panel is at least a quarter of a square metre, so this doesn't sound terribly practical unless you have an ultraportable and light usage habits.

[Tolya]

Some people already tried that. Read here

Well, in 2000 I traveled for seven weeks and over 2,500 miles from Alabama to Ontario with my solar panel, batteries, and laptop, and I can report that everything worked very well until the panel failed. I did not intend to use Windows much because it crashes more, takes much longer to reboot, and runs the hard drive more, but I had more battery time than I needed to work on the laptop, so the extra power required for Windows was a problem only for one period of time (in Connecticut, the laptop failed to shut down, and the battery was drained; for the next several days until the battery was recharged, my computer time was limited to an hour or so, so I went back to using DOS). Nor did it create any problem for me to use the laptop during the day for route finding when necessary, as the nicads were easily up to the task of recharging the laptop's battery. Even during cloudy and rainy weather, I was able to use the laptop a sufficient amount of time. Nor did Canada's high latitude hurt. On two occasions, the voltage of the nicads dropped below the desired amount, once dropping to 8.5 volts; however, on that occasion the voltage was rising rapidly and built up to 13 volts before morning. In fact, I learned to regard anything below 15 volts as low voltage, and almost always the nicads were above 16 volts when they had half a day or so to charge. Any time the voltage was above 16 volts, I knew I could work for two or two and a half hours without any problem. I also did not notice any overcharging problems, although I unhooked the panel for part of the day when I had not used the nicads the night before. The panel failed on the same day that I accidently kicked it while getting off of the bike, so that was evidently the cause of the failure. At any rate, one of the internal connections failed, and I received a free replacement after I got home.

In 2003, I traveled for fifteen weeks and 6,500 miles, using the panel, batteries, and laptop without serious problems. On several occasions, I found I did not have sufficient battery power to finish writing my day's account at night, at other times I was too tired; in both cases, I caught up on my writing using AC power during the day instead. I often looked at my highway atlas or other computer information during the night as well. On a couple of occasions, I downloaded photos from my camera and backed up my hard drive using my solar-charged battery, but normally I carried out those functions when I had access to AC. A problem I experienced but could not completely solve was that during the second half of my trip, the laptop would not always completely shut down; therefore, the laptop's internal battery would be down to 85% when I would restart, and as a result, the amount of time that I could use the computer was reduced due to the battery recharging while I was working. I had no problems due to the batteries overcharging or discharging too deeply.