navienavnav
Member level 1
I have a setup of 4 solar panels in parallel which, under direct sunlight yields the following result :
Open-terminal voltage : 5.6 to 6 V
Current with terminals shorted through multimeter : 0.9 to 1.1 A
When I directly use the solar panels to charge the phone, the charging current on the phone (though an android app) is showed to be around 150mA. Needless to say, this is very poor and doesn't even charge the phone considerably.
When charging from the wall charger, the app shows the current to be around 500 to 600 ma and when through USB, it shows it to be 300 to 360 mA.
So, I thought that maybe the shorted terminal current for the solar panel setup should have been much higher for it to be a practical solution. So I did this test :
I cut a USB cable halfway(which was lying around) to expose its wires and then using a multimeter, measured its open terminal voltage (the + and - pins) and then shorted them through the multimeter while connected to the aforementioned wall charger to measure the current. These were the readings :
Open-terminal voltage : 5.21 V
Current with terminals shorted through multimeter: 0.92 A
Now, this has confused me. According to this data, my solar panel setup should be powerful enough to charge the phone.
What I've already tried with no success:
-> Shorting the Data+ and Data- pins.
-> Putting a resistance of nearly 200 Ohms between the data pins.
I think it might have to do with some sort of switched mode power supply kind of a thing working here. Is it so? And if it is so, then does "SMPS" method works while charging from USB too?
Do I need any additional circuit to properly utilize the power provided by the solar panel?
Please help
Open-terminal voltage : 5.6 to 6 V
Current with terminals shorted through multimeter : 0.9 to 1.1 A
When I directly use the solar panels to charge the phone, the charging current on the phone (though an android app) is showed to be around 150mA. Needless to say, this is very poor and doesn't even charge the phone considerably.
When charging from the wall charger, the app shows the current to be around 500 to 600 ma and when through USB, it shows it to be 300 to 360 mA.
So, I thought that maybe the shorted terminal current for the solar panel setup should have been much higher for it to be a practical solution. So I did this test :
I cut a USB cable halfway(which was lying around) to expose its wires and then using a multimeter, measured its open terminal voltage (the + and - pins) and then shorted them through the multimeter while connected to the aforementioned wall charger to measure the current. These were the readings :
Open-terminal voltage : 5.21 V
Current with terminals shorted through multimeter: 0.92 A
Now, this has confused me. According to this data, my solar panel setup should be powerful enough to charge the phone.
What I've already tried with no success:
-> Shorting the Data+ and Data- pins.
-> Putting a resistance of nearly 200 Ohms between the data pins.
I think it might have to do with some sort of switched mode power supply kind of a thing working here. Is it so? And if it is so, then does "SMPS" method works while charging from USB too?
Do I need any additional circuit to properly utilize the power provided by the solar panel?
Please help