Although this is a week old post, thought I'd mention one simple fix for the mobile power issue.
"Hello, Looking into it some more I see some problems. The W520 requires a 170 watt adapter and the choices for running off the car battery are not there. There are also comments that the performance is throttled back on battery. I want a laptop that will work off of car power. It might be better to go with a T520 but I do not see any USB3 offered. The other choice is T420s for USB3. I am wondering how much of an upgrade the T420s is over a T61. 73 Eric" Keep in mind that a notebook packaged with an adaptor of xx watts draws less than that. The power supply covers many different model notebooks, and covers the peak demand at 100% cpu, max screen, with stuff off the usb ports and maximum draw from a discharged battery. Take a look at the battery maximiser applet and see what you're typically using; it'll be less than half the brick's rated output. A car battery and charging system has a vastly larger capacity than required by a laptop running at max cpu, fan, and screen brightness. A medium car batt stores over 700 watt-hours. Delivering the power is another matter but not difficult. i. Many cars have either a 12v power port for such purposes or a cig lighter socket with excess amp capacity for use with accessories. If not, you can easily wire in a high capacity socket with appropriate auto wiring methods. ii. Cheap DC-AC inverters deliver square waves not sine and add noise on top of that. If's also another gadget to keep track of. Better to get a computer mobile adaptor which has it's own, adaquate quality DC-DC adapter e.g. lenovo-branded auto/air adaptor. Moderate quality DC-AC inverters (around $100) are a little better and have will cut out before discharging the car battery below what's needed to start the car. If you are going to do this constantly in the same car for and for hours at a time, simply wire in an aux battery with an isolator. Then you can discharge the aux car batt, which still has huge capacity compared to a laptop's needs, and not discharge your car's starting batt. Use a deep cycle aux batt, a common item. _______________________________________________ Thinkpad mailing list [email protected] http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
