Article: 8854 of comp.sys.laptops Newsgroups: comp.sys.laptops Path: uwm.edu!spool.mu.edu!sol.ctr.columbia.edu!usenet.ucs.indiana.edu!silver.ucs.indiana.edu!wilkr From: wilkr@silver.ucs.indiana.edu (richard wilk) Subject: Ideas & Help needed: Running Laptop from Car Battery Message-ID: Summary: How can this be done??? Sender: Richard Wilk (wilkr@iubacs, wilkr@ucs.indiana.edu) Nntp-Posting-Host: silver.ucs.indiana.edu Organization: Indiana University Date: Thu, 21 Jan 1993 19:45:28 GMT Lines: 53 I need some feedback, advice and tech help on the following problem. I will be spending the summer living in a tent in Central America, miles from the nearest power line. I will be spending most of my time writing on my no-name clone 386SX laptop. This uses a fairly standard 12V nicad battery, and generally gives me about 1.25 hours. I have located a couple of photo-volataic trickle-chargers which will take about 8 hours to charge my battery (the cheapest one I have found is from a company in Ann Arbor, at 313 453-6746 if you are interested). But this will only give me an hour of writing a day. We have the money to buy a 4000 watt coleman generator (best price so far about $425), but not enough money to run it more than 2-3 hours a night (and who wants the noise anyway). We may have enough also for a small PV array, but I don't know how large or what wattage. I am presently thinking about buying a car battery down there, a battery charger, and an inverter. Then I would charge the car battery every night, and run the computer off it through the inverter the next day. Damark has a 100 watt inverter for sale right now for c. $70. Questions: Will this work? Has anyone tried something similar? Sub-questions: How long do I have to run the generator to get the battery charged? How big a PV array would I need to replace the generator completely? (we will be running a few lights and radios in the evenings too) How many hours of use can I expect to get out of a car battery if the computer is drawing about 45 watts (I *think* that is what the manual says). Does it make any sense at all to be going from 110 volts AC (battery charger) to 12 Volts DC (battery) to 110 volts AC (inverter, computer power supply) to 12 Volts DC (computer power jack)????? Is there any way to feed the computer, safely, straight from the car battery?? I would appreciate hearing from anyone with experience, ideas or knowledge (there must be someone with all three). Thanks very much Rick Wilk -- Richard Wilk Anthropology Dept. wilkr@iubacs Indiana University voice 812-855-8162 Bloomington, IN 47405 "Things are more like they are now than they've ever been before."