wad wrote: > > The context is that we are trying to ensure that an Maximum > Power Point Tracking algorithm can be implemented on the DC > power input of the XO-1.5. > > On Aug 5, 2009, at 10:56 PM, Richard A. Smith wrote: > > > John Watlington wrote: > > > >> The problem comes from the need for the algorithm to start > >> from a position of low current drain. The MPPT algorithm > >> should probably be disabled when the laptop is running and > >> the battery is below some threshold (say 10 -15% ?) > > > > Yep. I don't think it will matter though. The core of the > > problem is that our peak CPU power draw is > 10W where on > > gen 1 is was <=10W and we aren't going to fix that. > > We should play with having the power daemon clock down the CPU in > some cases.
how much would that save? how fast would the reaction time need to be? (i.e., how responsive does the MPPT algorithm need to be? > > Perhaps modifying adding a "solar power provided or removed" subtype > to the Battery Status Change SCI interrupt from the EC ? how would this be detected automatically? by voltage level? > This could be used to limit the peak processor clock when the battery > is very low. > > Limiting the peak processor clock when the battery is very low > and we don't have any DC input might extend the battery life > slightly as well. how much remaining runtime are we talking about, when we talk about "very low"? and again, how much can we affect the end result? paul =--------------------- paul fox, [email protected] _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
