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Mintyboost Solar Charger
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Mintyboost Solar Charger

by baxterb on Thu Nov 04, 2010 5:19 pm

I am having some problems charging the lithium ion battery with the 5-12 V charge controller. I am using two Powerfilm MP7.2-75 panels connected in parallel as the power source for the circuit. Each panel is rated at .72 W with an output of 7.2 V and 100 mA.

Once the battery voltage is high enough I connect my iphone to the mintyboost. This works great and the battery gets drained until it reaches its minimum voltage and shuts off. I then try and charge the battery again with the panels but only the green "Power" led lights up. The yellow "charging" led never turns on and the battery doesn't appear to charge. The voltage across the battery terminal reads .7 V and stays there even if the panel is plugged in for over a day.

I have been able to connect a mini usb from the computer to the charge controller and the battery begins to charge. I only need to plug in the source from the computer for under 5 seconds and then plugging in the panels works.

If you have any idea why the panels can't start the charge once the battery has been drained it would be greatly appreciated. Also if there is any way to make is so that I don't need to jump start the charge.
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charging circuit.jpg
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baxterb
 
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Re: Mintyboost Solar Charger

by adafruit on Thu Nov 04, 2010 5:23 pm

do the panels ever charge the battery?

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Re: Mintyboost Solar Charger

by baxterb on Thu Nov 04, 2010 5:38 pm

Yes, the panels charge the battery after the initial jump start from another source.

Thanks
Ben
baxterb
 
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Re: Mintyboost Solar Charger

by adafruit on Fri Nov 05, 2010 1:23 pm

try removing the charging-rate resistor so that you can change the charge rate to 100mA, it could be the panels just can't provide enough current?

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Please be positive and constructive with your questions and comments.