Hello,
I am using the Solar Charger (PID 390) with a 6v Solar Panel. I notice in full sunlight the chargers red and orange LEDs are lit constantly, however; when the sunlight becomes weaker (say due to clouds), both the red and orange LEDs flicker. The weaker the sunlight the longer the time between each flicker. The stronger the sunlight, the faster the flicker, and when there is full sunlight there is no flicker, the LEDs remain lit constantly. What does this mean? When the LEDs flicker, is the Lithium battery still being charged?
Solar Charger (PID 390) Charging Leds
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- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Solar Charger (PID 390) Charging Leds
When the sun is weak, the panel can't produce enough current at a high enough voltage to effect a charge. Rather than throw away this marginal power, it is used to charge up the large capacitor, and when there is enough of a charge in the capacitor, it is discharged through the charge controller into the battery. So the battery is charging in increments, whenever the led flashes.
- amahpour
- Posts: 108
- Joined: Mon Feb 03, 2014 4:16 pm
Re: Solar Charger (PID 390) Charging Leds
Where can I find test data on this? I'm finding that this "trickle" charge is pretty negligible with respect to my power consumption. Will MPPT be the best solution for cloudy environments?
- adafruit_support_bill
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Re: Solar Charger (PID 390) Charging Leds
Sounds like you need a bigger panel. MPPT is not such an effective solution for low-voltage applications.
See here:
https://learn.adafruit.com/usb-dc-and-s ... sign-notes
And here:
https://learn.adafruit.com/usb-dc-and-s ... harger/faq
See here:
https://learn.adafruit.com/usb-dc-and-s ... sign-notes
And here:
https://learn.adafruit.com/usb-dc-and-s ... harger/faq
- amahpour
- Posts: 108
- Joined: Mon Feb 03, 2014 4:16 pm
Re: Solar Charger (PID 390) Charging Leds
So the trickle charge going into the BFC (big freakin capacitor) is just as much as the MPPT going straight to the LiPoly? In either case I would have to size up the panel?
- adafruit_support_bill
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- Joined: Sat Feb 07, 2009 10:11 am
Re: Solar Charger (PID 390) Charging Leds
Pretty much. If you try to pull more current from the panel, the voltage will collapse completely. Both the MPPT and the VPCC+BFC will throttle the current back to avoid overloading the panel. If you want more current in low-light conditions, the only option is a higher capacity panel.
- amahpour
- Posts: 108
- Joined: Mon Feb 03, 2014 4:16 pm
Re: Solar Charger (PID 390) Charging Leds
So higher capacity as a function of current or voltage?
- zener
- Posts: 4567
- Joined: Sat Feb 21, 2009 2:38 am
Re: Solar Charger (PID 390) Charging Leds
Both. Panels are rated in Watts.
- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Solar Charger (PID 390) Charging Leds
As Zener says, panels are rated by watts, where watts = volts * amps.
The solar charger is limited to a maximum of 6 volts, so you need to find a 6v panel with a higher watt rating. We carry 6v panels ranging from 1 watt to 5.6 watts.
https://www.adafruit.com/search?q=solar+panel&b=1
The solar charger is limited to a maximum of 6 volts, so you need to find a 6v panel with a higher watt rating. We carry 6v panels ranging from 1 watt to 5.6 watts.
https://www.adafruit.com/search?q=solar+panel&b=1
- amahpour
- Posts: 108
- Joined: Mon Feb 03, 2014 4:16 pm
Re: Solar Charger (PID 390) Charging Leds
So in that case if I need to size up to a 6W panel then I need to change the resistor on the solar charging board to handle 1000mA, correct?
- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Solar Charger (PID 390) Charging Leds
If your battery can handle a 1A charge rate, than yes. Most of the cells we carry can handle a 1C charge rate. So if your LiPo cell is 1000mAh or larger, then 1A should be a safe rate.
Even without the resistor change, a higher capacity panel will be able to provide more current to the load.
Even without the resistor change, a higher capacity panel will be able to provide more current to the load.
Please be positive and constructive with your questions and comments.