Gotcha, thanks for your input. I'll be purchasing a cigarette lighter 1-to-2 (most likely) splitter pretty soon, for both the touchscreen and the dc-dc car adapter for the laptop, which i will also be purchasing soon.
Another update: I actually took my pre-existing carputer build, took the troubled HDD out of it, connected it to my home-desktop computer, and formatted it, installed windows in it, and it seems to be working somewhat fine, i was able to boot and reboot multiple times, successfully. I should have maybe ran a diskcheck, but oh well. I'll be replacing my dad's crappy old dell desktop with this one (although it's too good for him, haha), he'll probably just find a way to destroy it. But a 250GB HDD is too much space for him to be using, so i think i will get an external enclosure for this hdd and use it for personal use, buy a cheap sata 40GB for him.
Please don't run your laptop off your cig lighter. Run a dedicated line to the battery, that way you know the line can handle the power you need. There are a great many discussions on these forums about why not to use the cig lighter for any real power, it basically boils down to wires being under-sized for the stock fuses, and shoddy connections generating heat.
Oh Malcolm, you beat me to it...
I was going to use the same "2kToaster" pic on the 12volt last week but the thread got locked.
IMO any cig socket current above a few Amps is risky unless you know its quality.
Even then, contacts corrode etc.
And disconnections can occur. (Why subject a laptop to unnecessary power and battery-charge/discharge cycles?)
Also cig-socket usually power off during cranking.
Much better to run PC & audio etc direct from the battery - with a fuse obviously, and usually a relay that can be controlled from any combination of ACC, IGN, manual switch, timer, low-voltage or other signals.
Hey azngujuonfire, check out my build log below specifically page 1, post #8 for more detail on the PS. I am coming up on two years with no hardware failures. I would suggest the Carnetix 1900 or 2100 for a power supply. I does it all for a laptop: 18/19/20V, 12V, 5V, delay on for amps, engine crank protected etc. As stated above, the cig lighter does not have the wirign etc designed to offer the amount of current you will need safely.
Yeah I was first looking at the carnetix PSU, but unfortunately I don't have the money for it (summer classes at college start up today and tuition is $1400 out of my own pocket, since scholarship doesn't cover summers). I was thinking recently, however. What if I wired a separate cigarette lighter socket directly from the battery, with a switch so that I have it off when the car is off (so battery doesn't drain), use a proper fuse and gauge wire. Having the switch would allow me to turn the power to the dc-dc power brick on AFTER the car has started so that I don't have to deal with crank.
PhilG what is your experience with video noise from your carnetix PSU?
My cig lighter is 12V, 10A so that means it's fused for the maximum draw of 120W right? My laptop's charger is 75W, plus the monitor. Would this be safe? What are your opinions on inverters?
Inverters can be safe, but the dearth of them run hot when any real power is needed, have a mechanical fan in some cases, and typically use about 40-50% of the power they draw in waste heating their often inadequate heat sinks. Then what happens? You take the AC feed and convert it back to DC in various wall warts, where you waste even more current creating even more heat. What you want to do, whenever possible, is adapt a DC-DC power supply. Most electronics either have a car adapter available, or an adapter can be terminated to attach at the normal power port. Inverters are to be avoided in most cases....I know they're convenient and often seem to be the only solution, but rarely do they present the only, or the best, solution.
Originally Posted by azngujuonfire
Cig lighter connections are built for more power draw than they used to be (manufacturers anticipate users connecting a laptop or getting crazy with an inverter), but nothing beats a 30-amp 12v car relay (found at Radio Shack) and adequate conductor size going back to the battery, with appropriate fusing. This will allow you to connect your amp remote wires and any/all 12v devices you're likely to have, to a source that's as fused as you want it to be, doesn't waste power, and allows you to do away with immense cigarette lighter barrel plugs. You can fab a box to house your relay, stripped down DC-DC converters, fusing, and a wire terminal block, then octopus your various voltage wires out from there, thus keeping your system neat and tidy. I do this with my laptop power supply, my touch screen regulated 12 volts, 12 volts to my audio processor and satellite receiver, my regulated 5 volts for USB applications, and the remote wires to my amps. All the wires out are color coded. My amps get dedicated battery feeds with separate fusing for main power, but their remote turn-on wires come off the relay.