From: Pete M. <pet...@al...> - 2007-09-26 11:29:51
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Does anyone have any experience powering the Gumstix with Li-Ion or Li-Polymer battery packs? Common voltages for such packs seem to be 3.7v or 7.4v. (www.batteryspace.com) The Gumstix power FAQ says the input voltage is needs to be between 3.5v and 6v. Given that, there are basically two options as I understand it. 1. Use a 3.7v pack 2. Use a 7.4v pack with a switching voltage converter to output 5v http://www.dimensionengineering.com/DE-SW050.htm Does anyone have any experience on which one of these is a better Idea? The concern I have with option 1 is that it seems very close to the minimum which the wiki also states could be unreliable. On the other hand I've read that switching voltage regulators have the draw back of adding noise to the power (will this be a problem for the gumstix?) and some data sheets mention that you need to mount them at a distance from any RF components (is true with all voltage regulators or do just some that have this problem?) which could be a problem since I need to use wireless. Thoughts? Is there a better third option? Thanks, -Pete |
From: Luis J. Villanueva-R. <ljv...@co...> - 2007-09-26 17:14:21
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Hi, I have been using 3.7 Li-Ion batteries with the Gumstix. The system works well for several hours, depending on the processing and the mAh rating of the batteries. I may be wrong, but I think Li-Ions are supposed to keep their voltage for almost all their cycle, so they should not drop below what the Gumstix needs until they are almost out of juice. Hope this helps. Luis J. Villanueva-Rivera ljv...@co... http://www.CoquiPR.com Graduate Student Human-Environment Modeling & Analysis Facility Purdue University 195 Marsteller Street West Lafayette IN 47907 Pete Morici wrote: > Does anyone have any experience powering the Gumstix with Li-Ion or > Li-Polymer battery packs? Common voltages for such packs seem to be > 3.7v or 7.4v. (www.batteryspace.com) The Gumstix power FAQ says the > input voltage is needs to be between 3.5v and 6v. Given that, there > are basically two options as I understand it. > > 1. Use a 3.7v pack > > 2. Use a 7.4v pack with a switching voltage converter to output 5v > http://www.dimensionengineering.com/DE-SW050.htm > > Does anyone have any experience on which one of these is a better Idea? > > The concern I have with option 1 is that it seems very close to the > minimum which the wiki also states could be unreliable. On the other > hand I've read that switching voltage regulators have the draw back of > adding noise to the power (will this be a problem for the gumstix?) > and some data sheets mention that you need to mount them at a distance > from any RF components (is true with all voltage regulators or do just > some that have this problem?) which could be a problem since I need to > use wireless. > > Thoughts? Is there a better third option? > > Thanks, > -Pete > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |
From: Duane B. <dua...@gm...> - 2007-09-26 19:15:53
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On 9/26/07, Luis J. Villanueva-Rivera <ljv...@co...> wrote: > I have been using 3.7 Li-Ion batteries with the Gumstix. The system > works well for several hours, depending on the processing and the mAh > rating of the batteries. > I may be wrong, but I think Li-Ions are supposed to keep their voltage > for almost all their cycle, so they should not drop below what the > Gumstix needs until they are almost out of juice. Also, I believe 3.7V is the nominal cell voltage. Fully charged, they're closer to 4.1-4.2V per cell. |