At 12:38 PM -0700 8/1/02, Bruce Johnson wrote: >[EMAIL PROTECTED] wrote: >> One option is to use a motorcycle battery, and use an auto adaptor to run >> your PB from it... > >And get one of these to charge it: > ><http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41144> > >Or > ><http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38055> > >or go big and get one of these: > ><http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41432> > >Heck, so long as you're driving into the site and not hiking, get a deep >discharge 12V battery, like for marine or RV use, one of the 5W chargers >above and you'ld probably be able to run the laptop indefinitely, and >have leftover power. The whole kit would probably be mountable in a >small wooden box and not weigh more than 50 lbs or so, depending on how >heavy the battery is. > >Just charge it up before you go into the boonies, and you're set. > >If you're hiking in I'd stick to a motorcycle or snowmobile battery...
Not indefinitely. I just checked the power draw on my 5300c (something I was planning on doing anyways). With the computer running and the battery fully charged the DC Adapter drew 13W. With the battery charging it drew 34W. Now a Solar panel rated at 15W produces that power only under optimal conditions. In real life you'll probably get more like 10-12W tops. That means that with the computer on you'll be discharging the battery slightly. With two such solar panels you might have a functioning system but three is probably better. The portable battery pack I have is rated at 13 A-H so it would be good for about 10-12 hours I suppose. Except that with lead acid batteries you don't want to fully discharge them, in fact it is usually recommended to not go below about 50% charge. A commercial grade solar power system has to be overengineered a lot to accommodate aging of the solar panels and batteries, overcast and other factors. -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting [EMAIL PROTECTED] "I'm a designated driver on the Information Super Highway" -- PowerBooks is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> PowerBooks list info: <http://lowendmac.com/lists/powerbooks.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/powerbooks%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
