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   sci.electronics.basics      Elementary questions about electronics      72,318 messages   

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   Message 71,043 of 72,318   
   AK to All   
   Re: Run time for leds   
   23 Apr 19 10:21:40   
   
   From: scientist77017@gmail.com   
      
   On Tuesday, April 23, 2019 at 1:00:45 AM UTC-5, whit3rd wrote:   
   > On Sunday, April 21, 2019 at 4:46:59 AM UTC-7, AK wrote:   
   > > On Sunday, April 21, 2019 at 5:10:50 AM UTC-5, default wrote:   
   > > > On Sat, 20 Apr 2019 20:18:46 -0700 (PDT), AK   
   > > >  wrote:   
   > > >   
   > > > >   
   > > > >I have (8) 5 watt leds that are run from a 12VDC source.   
   > > > >   
   > > > >(3 18650 batteries at 3000 Ma hrs each.   
   >   
   > > I did not see any calculation that determines run time.   
   >   
   > Oh, that's easy; the 18650 batteries are 4V each, so to get 12V you   
   > have them in series.   12V * 3000 mAh = energy in the batteries   
   > about 36 watt-hours.   So, 7 hours at 5W (one LED), or under an hour   
   > with eight at a time.   
   >   
   > That assumes no energy-losing other components (which is unlikely; most   
   > LED assemblies for "12V" nominal input have some required ballast resistance.   
      
   This is what I have.   
      
   "https://www.ebay.com/itm/10PCS-12v-Super-Bright-T10-5050-W5W-5S   
   D-Yellow-Wedge-Fog-158-168-194-LED-Bulbs/283422908666?ssPageName   
   STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649"   
      
   The leds are strange looking and there are 5 of them.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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