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2013-12-23
, 12:21
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Posts: 11 |
Thanked: 1 time |
Joined on Oct 2012
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#42
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Some calculations.
-From this post I found that the phone will run for two days with everything turned off. The shortest day in Holland is 8 hours, so for two days I have 16 hours of sunlight.
The phone has a 2100mAh, 3.8V, 7.98Wh battery, which holds 28728 Joules. This amount of energy has to be restored in 16 hours. The solar-charger thus has to have at least 0.5 Watts of power.
The panel I have in mind right now has 0.935 Watts of power. This panel has to be hooked up to a voltage regulator to ensure a steady 5 volts.
With an input of 5.5 volts from the projected panel, the step-up/down dc-dc regulator has a measured efficiency of +- 93%, which leaves a comfortable .87 watts for the phone.
This is about 175ma @ 5 volts. Your regular laptop usb2.0 does 500ma, so its about 1/3rd of that.
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2013-12-23
, 12:33
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Posts: 1,104 |
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Joined on Feb 2010
@ Holland
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#43
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The Following User Says Thank You to dirkvl For This Useful Post: | ||
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2014-09-03
, 18:26
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Posts: 1,104 |
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Joined on Feb 2010
@ Holland
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#44
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2014-09-03
, 19:41
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Posts: 6,447 |
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Joined on Sep 2012
@ UK
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#45
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2014-09-03
, 21:19
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Posts: 1,104 |
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Joined on Feb 2010
@ Holland
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#46
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The Following 3 Users Say Thank You to dirkvl For This Useful Post: | ||
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2014-09-03
, 21:31
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Posts: 6,436 |
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Joined on Nov 2011
@ Ängelholm, Sweden
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#47
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2014-09-03
, 22:11
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Posts: 433 |
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Joined on Oct 2012
@ Costa Blanca, Espaņa
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#48
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2014-09-04
, 00:51
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Posts: 193 |
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Joined on Dec 2009
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#49
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2014-09-04
, 01:29
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Posts: 1,335 |
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Joined on Jul 2010
@ Brittany, France
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#50
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Because my use case would be like: I'm on holidays and I know the batteries sometimes don't last the whole day. This is, in fact, a typical holiday problem: At home, there's a charger everywhere and I don't use the phone so much. When on holidays, I'm out all day long, no place to charge the phone, weak reception eats battery, I use both GPS and cam a lot more often than at home... Now if I could only help the battery survive the day by exposing it to bright sunlight while I'm having a break at enjoying some ice tea... that would be great.