Solar MintyBoost Help?

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marjet
 
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Solar MintyBoost Help?

Post by marjet »

I was hoping that someone would be able to help me troubleshoot my Solar MintyBoost. I had put this together this past fall, and put it to the test on a trip to Belize. Before I left on my trip, I tested it a few times and it worked. However, sometime during my trip in Belize, it stopped working. I have a feeling that I may have fried the chip from the direct sunlight in Belize.

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The interesting thing is that the CHRG light on the USB / DC / Solar Lithium Ion/Polymer charger - v1.0 turns on the second that the solar panel hits light, before the PWR button even starts flashing. Whenever it is out of the dark, it lights up. Additionally, the the CHRG light is constant while the PWR light is flickering, which did not used to happen when it was working properly.

Also, no matter how long I leave it in the sun, it never finishes charging.

When I put a multimeter to it, even in direct sunlight, it never reaches 5V. The most it goes is 3V. It also does not recognize or charge my iPhone at all. It alternates registering between 1.5V and 3V. Before the trip, it would register a constant voltage.

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Can anyone help me troubleshoot this issue and figure out if it is a part that I need to replace? I can't see any loose connections as of right now.

Thanks!

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adafruit_support_rick
 
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Re: Solar MintyBoost Help?

Post by adafruit_support_rick »

The battery may be damaged. Did you add the thermistor to prevent charging when the battery is too hot? I can imagine the temperature inside that box going over 50ºC in the Belize sunshine.

marjet
 
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Re: Solar MintyBoost Help?

Post by marjet »

I did not add a thermistor, but I did change out the battery and I tried with a 1000 mAh battery instead of the 1300 mAh battery and it did not make a difference. I did leave the box cracked open when I was charging the battery to try to keep the temperature down as well. Any other ideas?

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adafruit_support_bill
 
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Re: Solar MintyBoost Help?

Post by adafruit_support_bill »

Does it charge if you connect it to a USB port instead of the solar panel?

marjet
 
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Re: Solar MintyBoost Help?

Post by marjet »

I just tried to charge the battery. It does charge, and the DONE light turns on. If I unplug it and replug it, for some reason it takes another 20 minutes to be fully charged again. However, it does charge my phone through USB. Does this mean that the solar panel is fried?

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adafruit_support_bill
 
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Re: Solar MintyBoost Help?

Post by adafruit_support_bill »

If I unplug it and replug it, for some reason it takes another 20 minutes to be fully charged again.
The charge cycle is not linear. It has a pre-conditioning phase and a trickle-charge phase to top off the cell once final charge voltage is reached. When you reset the charge controller, it starts that cycle all over again.

If it charges via USB but not the panel, then I suspect your panel is damaged. You say it never gets over 3v in full sun. That would seem to confirm the theory.

marjet
 
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Re: Solar MintyBoost Help?

Post by marjet »

Thank you so much for your help in troubleshooting! I really appreciate your time.

A few quick follow up questions:
1. I fully charged my phone, but the USB/DC LiPoly Charger doesn't register as DONE when that happens. I'm not sure why that would be, but perhaps it's the lack of charge left in the battery. Is that normal? I can't recall what used to happen with the charger.
2. It took about 3 hours to charge an iPhone 5 from 20% to 100%. Does that sound about right?
3. I really am not sure why the CHRG light doesn't flicker with the PWR light. That used to happen. Does that indicate that something is off?

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adafruit_support_bill
 
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Re: Solar MintyBoost Help?

Post by adafruit_support_bill »

1. I fully charged my phone, but the USB/DC LiPoly Charger doesn't register as DONE when that happens. I'm not sure why that would be, but perhaps it's the lack of charge left in the battery. Is that normal? I can't recall what used to happen with the charger.
The "Done" light indicates the charge state of the LiPo cell connected to the charger - not the charge state of the phone. Some of the charge on the LiPo no doubt went into charging the phone, so the "Done" light will not come back on until it is fully recharged.
2. It took about 3 hours to charge an iPhone 5 from 20% to 100%. Does that sound about right?
That sounds about right. The Mintyboost maximum output is about 500mA. A lot of AC powered phone chargers these days will run at up to 1000mA, so they will charge the phone faster.
3. I really am not sure why the CHRG light doesn't flicker with the PWR light. That used to happen. Does that indicate that something is off?
Not sure I understand the question. Does the PWR light flicker when you are charging via USB?

marjet
 
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Re: Solar MintyBoost Help?

Post by marjet »

I didn't realize that the battery charged the phone at a quicker pace than the USB charged the battery. That makes more sense to me now.
3. I really am not sure why the CHRG light doesn't flicker with the PWR light. That used to happen. Does that indicate that something is off?
Not sure I understand the question. Does the PWR light flicker when you are charging via USB?
Sorry, I was referring to when charging in the sun. In partial sun, the PWR light used to flicker, and so would the CHRG light. Now, if it is in partial sun, the CHRG light doesn't flicker but the PWR light does. My initial understanding is that the charge is constant, which doesn't make sense. I was just curious about why that would be, and whether that is related to a faulty solar panel.

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adafruit_support_bill
 
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Re: Solar MintyBoost Help?

Post by adafruit_support_bill »

That is a good question. I've never run across that situation and I don't know how the indicator leds would react to it. If I get some time I might set up an experiment and try it.

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john444
 
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Re: Solar MintyBoost Help?

Post by john444 »

Hi Marjet,
marjet wrote:Now, if it is in partial sun, the CHRG light doesn't flicker but the PWR light does. My initial understanding is that the charge is constant, which doesn't make sense.
When the panel is in 'partial' sun, the charger is not getting enough current to charge continuously.
The large capacitor is there to soak up current until the charger has enough voltage to shove some into the battery. That is the cause of the flickering or pulsing 'power' LED.
The rate of pulsing depends on how much current the solar panel can supply.
My rough calculations indicate that the pulses/sec is equal the the current in mA's.
One pulse/sec is about equal to 1-mA from the solar-panel.
Ten pulse/sec is about equal to 10-mA from the solar-panel and so on.
It takes a long..... time to charge at 1-mA. But, at least you are getting something.

I do not believe that there is anything wrong with the solar-charger it is just that
the solar-panel puts out very little when it is not in 'full' sun.

Good Luck, John

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