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| Thread ID: 40062 | 2003-11-26 20:59:00 | Run laptop computer from 12vdc only | tedheath (537) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 194966 | 2003-11-26 20:59:00 | I am thinking about buying a cheap laptop to use in my truck to print out invoices, jobsheets, quotes, and store zillions of files instead of bits of paper I have at the moment. I don't really need to remove the laptop form the truck it will stay in the cab. I would like to know if I buy a laptop especially one with a rooted battery, will the laptop still function if permanently hooked into the trucks battery. Do laptops have connections for DC power other than ac dc adapters? If the voltage of the laptop is say 9vdc can I get a voltage reducer from Dick Smith etc will it handle the current? I know very little about their technical aspects. I have used them in East Timor but they were permanently hooked up to a AC/DC power adapter. When we wanted extra batteries during generator outages we had to get them out of the freezer! The batteries never seemed to last long and we used to lose heaps of data when they died. Cheers tedheath |
tedheath (537) | ||
| 194967 | 2003-11-26 21:11:00 | Laptops seem to all use the same voltage (at least those in the last 3 years or so) of 18v or 19v, at about 4 to 4 amps. So they will not run directly off 12 volts. You can get 12v switchmode inverters for them, but really its cheaper to buy a small (~140 watt) 12-240v inverter (around ~$100 or so) and use the laptops normal AC supply. The laptop would not need a battery, as you note already. The other advantage would be that a normal printer could also be used. You may need to go to a larger capacity inverter, but they are cheap. |
godfather (25) | ||
| 194968 | 2003-11-27 00:03:00 | One old one I had (a Tandy :D) required 17VDC (according to the nameplate) from its external supply. It ran happily from "12V" (a gel battery, which starts at about 13V. Yours might. The higher voltage is usually to provide enough to charge the internal battery. The actual volatge used by the computer PSU is often a nominal 12V. Your truck will normally be at 13.8 or so ... the automotive supply should not swing much. The maximum charging voltage will be 14.3 or so. But I think I'd be happier with an inverter producing 230V AC, for isolation... the surges of voltage in cars/trucks have always been notorious for zapping electronics. (Car radios are designed to stand it ;-); computers aren't). I'm running my more modern laptop off an inverter until I can find a replacment lithium ion battery for it. It's only "laser" printers (with 400W fuser bulbs) which would want more than a few tens of watts. |
Graham L (2) | ||
| 194969 | 2003-11-27 00:09:00 | I used to run a Brother Notebook off my home 12v solar panel/battery system, it used 9v dc so i got an electronics shop to make a voltage dropper. Worked fine, can't recall the wattage but minmal power use. Gave up on it in the end because the 32k memory drove me up the wall. Floppies in and out so much I thought the mechanism would conk out. Cheers. (not helpful post but thought I'd toss this in} |
mark c (247) | ||
| 194970 | 2003-11-27 00:13:00 | Although Tedheath doesn't say what size truck he has, most trucks have 24 volt systems. Would this allow more options for powering his laptop? | Andrew B (867) | ||
| 194971 | 2003-11-27 00:22:00 | I built a power supply for a Toshiba laptop. The laptop input was stated as 18 volts. Unless the supply was >17 volts the laptop totally ignored it. Based on that, chances of it operating on 13.8v is slim. I have another laptop here that uses 9 volts @ 500 mA Problem is its an 8088 CMOS processor, 1 MB RAM and DOS 2.11 in ROM. No HDD or CD ROM, just a single 720k Floppy. 1987 vintage, mono screen, but it still goes. Just don't try to run Windows on it. But it will run fine in a vehicle. |
godfather (25) | ||
| 194972 | 2003-11-27 02:49:00 | The truck is nominal 12vdc tedheath |
tedheath (537) | ||
| 194973 | 2003-11-27 02:59:00 | Did you know that American Trucks regardless of size are all 12 vdc Its so they can hitch up any trailer in any state with any truck and go. I know trucks from that Asian country that come second in WW2 are 24 vdc as are some European trucks. tedheath |
tedheath (537) | ||
| 194974 | 2003-11-27 05:20:00 | I use an inverter from Dick Smith in my van(12v-230v,150w)to run my laptop and an adsl router and have no problems at all.Works very well.That is probably your easiest option. | Peter Coleman (597) | ||
| 194975 | 2003-11-27 06:52:00 | I will get 300 watt inverter form Dick Smith they are on special at the moment I have bought a HP portable deskjet b&w printer from trademe it is quite an old model and the battery is rooted as well. Would 300 watts AC be ok to run both of them? I do know ohms law but there factors with effiency of the power conversion I guess. Thanks very much so far Graham, Mark, God, Andrew and Peter tedheath |
tedheath (537) | ||
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