Comparison of CLAITE 10W and SE05 5W solar panels

I tested the SE05 "5W" 5V solar panel in 2016:

https://bkhome.org/light/solar/panels-small-2016.htm

I recently purchased the CLAITE "10W" 5V solar panel:

https://bkhome.org/news/202103/10w-solar-panel-for-usb-charging.html

It has been cloudy recently, but today the clouds cleared, just a bit of faint mistiness, so did a quick comparison of these two panels.

Date is April 5, 2021, 1.00pm, fairly clear sunny sky, solar intensity reading is 830W/m2, ambient temperature is 30 degC -- Autumn, but quite a warm day. Negligible breeze.

I used resistances to place different loads on the panels, and plotted voltage-current graphs. Here is the CLAITE "10W" panel:

Here is the graph of the SE05 "5W" panel:

...in the latter graph, see the foldback effect, which I think is a very good feature.

For the SE05, the peak power point is about 4.78V @ 0.59A, which is 2.8W. For the CLAITE panel, peak power is only about 4.86V @ 0.6A, which is 2.9W. You see why I am putting those "5W" and "10W" ratings in quotes!

Hmmm, it seems that the CLAITE panel is throttling its output. It has a short-circuit current of 2.16A, which is an indicator that this panel potentially has a much higher peak power point.

I did a quick test connecting the CLAITE panel to two Android phones, and got 0.52A and 0.57A. My 2016 post explains D+ and D- pin connections required for Android phones. Shorting D+ and D- together made no difference.

Measuring the resistances between the GND, D+, D- and 5V pin on the USB socket, there are resistors connected to D+ and D-, indicating this panel is designed to charge Apple devices, not Android devices. Here is information for Apple devices:

https://www.instructables.com/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/

https://learn.adafruit.com/minty-boost/icharging

Anyway, connections of the D+ and D- pins does not matter when just applying resistance loads, as I did for the above graphs. The regulator in the CLAITE panel is throttling the output. It should not be doing that.

It looks like I will have to sacrifice this panel, see if can open up that regulator, maybe replace with my own that I built in 2016 -- see link at top of this post.

EDIT 2021-04-06:
Today, just after 11am, I noticed that the clouds had cleared, just some wispy clouds off to the sides, but quite intense blue overhead. Did a very quick test with the CLAITE panel, time 11.30am, April 6, 2021, Perth, Western Australia, sun intensity 885w/m2, ambient temperature 27 degC. Negligible breeze.

I did this very quickly, didn't allow the panel to completely warm up in the sun. Just brought it out from inside, aimed it at the sun, running through an inline voltage-current digital meter, and wrote down the readings.

Charging my Huawei phone, a 2019 model that I actually purchased early 2020 (so I escaped the Google embargo), battery was at 93% and the charging was 4.90V @ 0.78A, which is 3.82W.

Then plugged in my Voltaic V15 battery bank, which is approximately 50% charged, and read 5.05V @ 0.62A, which is 3.13W.

I expected better with the stronger sunlight, but those reading are nowhere near the claimed 10W!

I need to find out what the panel is actually capable of, without the regulator getting in the way. I used a serrated kitchen knife to cut the plastic covering, exposing the regulator:

...at the bottom are the two tabs from the panel, so I should be able to remove the regulator and solder directly to those tabs. The glue is flexible, probably a silicone sealant, so should be able to pry the board off.

The main chip is "XL1410E1" and on the next line "01103". Would be interesting to find the specs on it. 

EDIT 2021-04-14:
Here is a more accurate test of the CLAITE "10W" solar panel:

https://bkhome.org/news/202104/accurate-test-of-claite-10w-5v-solar-panel.html

...hikers, note the comment about the switching regulator!   

Tags: light