How to regulate the voltage from USB solar panel ?
I got some USB solar panels.
They output 3.5W at 6V each.
I think the usb wire is directly wired to the panel without regulator and without diode like it should be.
I would like to use them to power a usb power bank.
My problem is that I measure output voltage from 3,5 to 6V.
When there is a cloud, voltage is not enough and when there is full sun I get a little too much.
(Is it fine to charge at 6V instead of 5V through USB ?)
I would like to know if there is a simple way to regulate the voltage to 5V and to let the current fluctuate with the sun instead of the potential.
Ideally I would like to keep usb connectors (to avoid soldering, wiring and modify the circuit easily) but any idea is welcome.
Thank you :)