lpress@isi.edu (Laurence I. Press) (05/11/91)
Does anyone have any information or ideas on off-the-shelf or home-brew solar power for portables? Larry
cho@sol4.cs.psu.edu (Sehyeong Cho) (05/12/91)
In article <17913@venera.isi.edu> lpress@venera.isi.edu (Laurence I. Press) writes: >Does anyone have any information or ideas on off-the-shelf or home-brew >solar power for portables? > >Larry Is might not be a good idea for a back-lit screen laptop :-)
ts@uwasa.fi (Timo Salmi) (05/12/91)
In article <17913@venera.isi.edu> lpress@venera.isi.edu (Laurence I. Press) writes: >Does anyone have any information or ideas on off-the-shelf or home-brew >solar power for portables? The obvious one, that is using a compretely detached solar power unit. This solution should go with any laptop. I have personally used a solar panel for Zenith Z-181 at my summer cottage where we have a 12VD solar power unit with an accumulator in between for many puposes. But then, its not portable any more. But there are currently also some farily portable detached solar panels available. ................................................................... Prof. Timo Salmi Moderating at garbo.uwasa.fi anonymous ftp archives 128.214.12.37 School of Business Studies, University of Vaasa, SF-65101, Finland Internet: ts@chyde.uwasa.fi Funet: gado::salmi Bitnet: salmi@finfun
davidc@vlsisj.uucp (David Chapman) (05/14/91)
In article <17913@venera.isi.edu>, lpress@isi.edu (Laurence I. Press) writes: |> Does anyone have any information or ideas on off-the-shelf or home-brew |> solar power for portables? Most solar systems are designed to charge 12V DC systems (e.g. car batteries). Follow the current thread on 12V adapters and just plug a solar panel into the input of the DC-DC converter. Be aware that solar panel output varies wildly with the weather. For example, on a cloudy day power output may be only half that of a sunny day. So you will need to: 1) have a huge power margin on your solar panel, or 2) run the laptop from a 12V battery and recharge the battery from the solar panels, or 3) use the solar panels to recharge the internal battery and don't try to run the laptop directly from the solar panels. If you try option 1), watch out for the 18-20V open-circuit/low-load voltage output of the solar panels. This may apply for option 3) as well; make sure that the charger or DC-DC converter input is sturdy enough to take the higher voltage momentarily. Also, remember that solar panels are current-limited, so you buy capacity according to the current they supply, not the quoted wattage which is usually spec'd at 17V. I'm doing just this, and I will be using options 2) and 3). David Chapman {known world}!decwrl!vlsisj!davidc vlsisj!davidc@decwrl.dec.com