I don't think you really want that thing as most cheap inverters are terrible noise sources. High quality DC-DC inverters are available; you get one of appropriate output (voltage and current) and you then avoid the inefficiency of multiple conversions (each device has some inherent losses).
I expect that the 170 Watt brick is needed to run the quad core at full power along with a high power GPU (Nvidia) and 32 GB of RAM and charge an empty battery. Other devices like the chipset and disk(s) also take power. You may also need to charge the optional battery slice. The 94 Watt-hour battery probably takes at least 100 WH to fully charge. Let's assume a 4 hour charge time so we need 25 Watts for that. So the notebook probably pulls less than 150 Watts itself. Let's assume an 80% efficiency of the car adapter (DC-DC) so we pull about 190 watts from the car. Assuming the alternator is running we have about 14 volts so the adapter draws about 13.4 Amps or so as long as the wiring is good and we don't have too much voltage drop. Be careful where you plug that in as many power ports in cars are rated for only 10 Amps continuous. Note that the nominal 400 Watt inverter below would draw about 35 amps at full power assuming 80% efficiency and the alternator providing 14 volts at the inverter. That would blow most fused circuits in cars and would nearly drain a battery in a couple of hours with the engine off (current up to over 40 amps at 12 volts). Stuart On Nov 8, 2011, at 1:26 PM, Paul A. Pennington wrote: > Eric said: > > < The lack of a AC/DC combo adapter kills the deal. > > You can buy a 400-Watt inverter from Amazon for $20 that plugs into a 12V > socket and provides 115V for the computer. _______________________________________________ Thinkpad mailing list [email protected] http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
