Hi Drake, 25W should be the draw from the batteries after accounting for inverter efficiency. Note that the low power factor will reduce the effective inverter efficiency, since the inverter still has 49VA of reactive power causing losses. For a small switching power supply like the laptop's, the poor power factor is most likely caused by high current peaks as the internal capacitors charge for just a small fraction of the total sinewave cycle, rather than a large phase difference like you might see with a motor or other inductive load.
Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com On Tue, Dec 17, 2019 at 10:17 AM <drake.chamber...@redwoodalliance.org> wrote: > > Hello Wrenches, > > I checked my laptop with a Kill A Watt meter. It drew 25 W,but 49 VA. Which > number represents the true draw on the batteries? > > Thanks, > > Drake > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
