Quote:
Originally Posted by Tiersten
The battery inside the Kindle is a 3.7V Li Poly so wiring in your 8+V solar cells would be an extremely bad idea. Even with the 0.7V diode drop, you're going to be trying to feed it a significantly higher voltage than it is expecting. If you've wired all the solar cells in series then you're just going to end up with around 10mA in total and that is nowhere near enough to charge the Kindle considering it is expecting 500mA+.
The micro USB socket on the bottom also only will take 4.75V to 5.25V.
Charging a lithium battery directly isn't simple either. If you just try to charge it without the correct monitoring circuitry then you're risking a lithium fire.
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solar cells have high output impedance depending on light falling on the cells.the 8 volts figure is only true if no current is being drawn.as current is being drawn into the 3.7 volts lithium battery the output voltage will fall to just over 3.7 volt.
somebody measured the current consumption and it varied from 1 to 3 milliamps with wi-fi off and 3 to 6 milliamps with it on.
it is not about 500 mA in 3 hours...it is about trickle charging such that daily usage of the
initially fully charged kindle would be nearly replenished by the solar panel.
i have aware of lithium fires and the diode and uhu glue takes care of both.
solar cells will not cause over charging due to high output impedance of same.