Hello, I have a 13W usb solar charger which was capable to output ~1A charge current during my recent afternoon tests. The problem with it, that it resets (output voltage drops to 0V) every 1-2 minutes for about 4 seconds (I measured the output voltage with a portable scope).
I also have a power bank with % based charge state indication. The % signal is quite precise, if the power bank is charged from a power adapter, % gets incremented after every ~90mAh. (I tested it with a USB tester)
My problem is that, if I charge this power bank with the solar charger the % indication never increments, even after the USB tester measured 400-500mAh electric charge.
How is this possible? The power bank's charge electronics somehow gets tricked by the occasional 0V voltage drop?
I had one of those foldable photovoltaic collectors and it barely charged my phone (I was in a very sunny place). Another try for me with a "solar battery" would only charge its own battery to 50% (it would charge to 100% only on a USB tether). Batteries needs more than voltage potential. They need current flow that the panels might not supply. Good luck.
Makes sense, this is why I measured the current with an USB tester (and for a short test my diy Hall sensor based current tester). The current flows evenly (except for that 4sec voltage drop).
@TomGeorge: this is specifically an USB charger unit, should be compatible with any USB device. I'm not saying it does not work, beacuse it charges my phone for example (although a little annoying that the charging starts over every 1-2 minutes). My problem is that somehow the powerbank's % monitoring is not consistent with the delivered electric charge, when charged with this solar unit.
At night all solar cells will draw current from the battery through the solar controller. Current being drawn by the solar cell from the battery can damage individual cells of the solar cell. Bypass and blocking diodes are a solar cell requirement for proper long term solar cell operations.
