Item: RAV Power 24Watt 3Port backpack solar panel
Item charged: Samsung 3.8Volt, 9.88Wh, 2600mAh cell phone battery inside of a SG4
*The phone battery has been in my sole possesion for about 3 years (was part of the phone package I purchased).
*The phone was not off but was in airplane mode while charging.
20180724 at 2:22pm attached phone to middle port.
phone's battery was at 7% power before attaching to solar panel
2:55pm phone's battery 37%
3:22pm phone's battery 67%
3:45pm phone's battery 89%
3:55pm phone's battery 94%
note: had to reposition panel as 1.5 panels were partially shaded by tree.
4:05pm phone's battery 96%
4:10 to 4:13pm phone's battery remained at 97%
4:17pm 98%
4:25pm 99%
4:32pm 100% I did not watch the phone's charge level for the last 7 minutes so it may have reached 100% before 4:32pm.
I've noticed the same trend in wall charging of my samsung battery; the battery charges at a much slower rate for the last 10% of the a battery power than the first 90% of the a battery. This is also true for batteries in solar battery banks that I've worked on.
So for a 3.8 volt 9.88Wh, 2.6Ah cell battery, it takes a full two hours to charge in full sun between 2pm and 4pm end of July (yeah it does matter).
What might increase the speed???
-did not try for perpendicular angle with sun;
-phone was in airplane mode but not off.
However, for a 2.6Ah cell phone battery, you can expect it to charge %10 for every 10 minutes up to 90%.....it's that last 10 percent which will take forever!!!
....1 hour charged sixty percent!!!
If you strap this to your backpack and you hike through shadows, your charge time will be hella longer (40 to 60% longer).
The tiny house got a tiny bit more wool in its walls while I waited for the battery to charge...more to come later on the tiny house. I've one more solar backpack panel to test for some people first.
