Hello. I purchased the Adafruit Universal USB / DC / Solar Lithium Ion/Polymer charger - bq24074 PID: 4755 a week or so ago to use as a solar charger for my raspberry pi project. everything seems to be working except the Solar part. I can charge the battery using the USB-C cable and the charge light comes on. When trying to charge over solar the charge light does not come on.
I have narrowed it down to the charger itself. When measuring voltage coming from the 6W (medium) solar panel in early morning hours (1000 EST) with the panel laying flat on the ground in sunlight, the panel puts out 7.5v. when I plug the panel into the charger I can see the same 7.5v at the barrel jack itself by placing my multimeter POS+ lead on the back of the barrel jack and the NEG- to the soldered header where it attaches to the board itself. When I put my POS+ lead on the soldered point where the jack connects to the board rather than the back of the jack the voltage is around 0.5v.
I have checked with and without LIPO attached and I have checked at the DC port, barrel heads, LIPO and LOAD heads as well. Everywhere on the board itself is around 0.5v and up to the charger is 7.5v.
Please let me know if I am doing something wrong, testing in the wrong places or perhaps the DC port on my board is bad. Thank you for your help in advance.
Solar does not appear to work on Adafruit Universal USB / DC
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- Darthux
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- adafruit_support_mike
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Re: Solar does not appear to work on Adafruit Universal USB
Post a photo showing the measurement you're getting and we'll take a look. 800x600 images usually work best.
- Darthux
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Re: Solar does not appear to work on Adafruit Universal USB
Attached are the photos I took this morning at 1030 EST with the solar panel laying flat in view of the sunlight.
there will be two posts because 3 files is the limit
there will be two posts because 3 files is the limit
- Darthux
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Re: Solar does not appear to work on Adafruit Universal USB
Darthux wrote:Attached are the photos I took this morning at 1030 EST with the solar panel laying flat in view of the sunlight.
there will be two posts because 3 files is the limit
- adafruit_support_mike
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Re: Solar does not appear to work on Adafruit Universal USB
Thank you, it’s always important to know what points in a circuit are being measured.
There are a couple more measurements that will give us useful info though:
With nothing connected to the BAT or LOAD ports, measure the voltage between the pads for the optional capacitor with USB power and power from the solar panel. If you see the same 5V/nothing there, it will mean the diode just past the DC barrel jack is dead.
If you do see voltage from the solar panel between the capacitor pads, connect a partially-discharged LiPo to the BAT port and some kind of circuit to the LOAD port and measure the voltage from the solar panel as seen between the capacitor pads again.
A solar panel’s voltage depends on the amount of current it’s pushing, and drops off quickly past a value called the Maximum Power Point. Let’s get a snapshot of how the voltage changes under load.
There are a couple more measurements that will give us useful info though:
With nothing connected to the BAT or LOAD ports, measure the voltage between the pads for the optional capacitor with USB power and power from the solar panel. If you see the same 5V/nothing there, it will mean the diode just past the DC barrel jack is dead.
If you do see voltage from the solar panel between the capacitor pads, connect a partially-discharged LiPo to the BAT port and some kind of circuit to the LOAD port and measure the voltage from the solar panel as seen between the capacitor pads again.
A solar panel’s voltage depends on the amount of current it’s pushing, and drops off quickly past a value called the Maximum Power Point. Let’s get a snapshot of how the voltage changes under load.
- Darthux
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Re: Solar does not appear to work on Adafruit Universal USB
Over USB-C I am seeing 4.93Vadafruit_support_mike wrote:With nothing connected to the BAT or LOAD ports, measure the voltage between the pads for the optional capacitor with USB power and power from the solar panel.
Over Solar I get 0.13V
Because I did not see 0V, I did this anyway and got 4.42V using USB-C and 0.1V with solar plugged in.adafruit_support_mike wrote:If you do see voltage from the solar panel between the capacitor pads, connect a partially-discharged LiPo to the BAT port and some kind of circuit to the LOAD port and measure the voltage from the solar panel as seen between the capacitor pads again.
- adafruit_support_mike
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Re: Solar does not appear to work on Adafruit Universal USB
There we go. That’s enough to authorize a replacement, thank you.
Send a note containing a link to this page and your order number to [email protected]. The folks there will get you a replacement Solar Charger.
If you want to keep testing the Charger you have, try shorting the diode next to the DC barrel jack while measuring the voltage between the capacitor pads. It’s the black rectangle with an etched stripe across one end near the end of the barrel jack. If that makes the voltage show up, you can either short the diode permanently with a piece of wire or pull the diode and replace it.
Send a note containing a link to this page and your order number to [email protected]. The folks there will get you a replacement Solar Charger.
If you want to keep testing the Charger you have, try shorting the diode next to the DC barrel jack while measuring the voltage between the capacitor pads. It’s the black rectangle with an etched stripe across one end near the end of the barrel jack. If that makes the voltage show up, you can either short the diode permanently with a piece of wire or pull the diode and replace it.
- Darthux
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Re: Solar does not appear to work on Adafruit Universal USB
Thank you Mike. I’ll do that now.
- erebollo
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Re: Solar does not appear to work on Adafruit Universal USB
How do you make the setup for your raspberry pi? I want to run my raspberry pi zero w 24/7 in a remote location.Darthux wrote:Thank you Mike. I’ll do that now.
- Darthux
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Re: Solar does not appear to work on Adafruit Universal USB
I use https://www.adafruit.com/product/1903 connected to the out port of the solar charger the lipo chargererebollo wrote:How do you make the setup for your raspberry pi? I want to run my raspberry pi zero w 24/7 in a remote location.Darthux wrote:Thank you Mike. I’ll do that now.
- erebollo
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Re: Solar does not appear to work on Adafruit Universal USB
Darthux wrote:I use https://www.adafruit.com/product/1903 connected to the out port of the solar charger the lipo chargererebollo wrote:How do you make the setup for your raspberry pi? I want to run my raspberry pi zero w 24/7 in a remote location.Darthux wrote:Thank you Mike. I’ll do that now.
Darthux, Thanks for the information. Can you upload a diagram how to connect the the components between the Raspberry Pi, USB/DC Solar LiPo and the Power Boost 500?
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