I have several of these type of portable solar panels as part of our hurricane prep supplies at home, so let me pass on a few tips I’ve learned about them over the years.
First, the power output from these panels is not constant (obviously) as it depends on the intensity and continuity of the sunlight it is exposed to. Clouds or even passing shadows can cause a dip in voltage which may cause your device to stop charging until the obstruction is gone; you also may need to unplug and re-plug your device in order to get it to resume charging.
Second, if you charge your phone directly from a solar cell, better to turn your phone off first. It will charge much quicker that way. If you can’t (or if it won’t charge when it’s off) then turn on the Airplane Mode so the cell radio, wi-fi radio and Bluetooth are off and not using power so more goes into the battery. And keep the screen off, otherwise it might take you a day or more to get a full charge.
And Third, I find it much easier to use a solar cell to charge a small power bank battery during the day, then use that battery to charge your cell phone overnight as you sleep. Power bank batteries (which can be had for around $10) are not nearly as picky as a cell phone when it comes to charging, and when full will provide your phone with clean uninterrupted power overnight when you are not using it.
Just thought I’d pass this along.
Will this panel allow trickle charging of larger items, like a small laptop? Can it be daisy-chained?
Sorry for the delay, now that the offer ended. But, this is what we got back from the vendor:
*This item will charge any USB powered device. It will not power larger items such as full size laptops.
It is not possible to daisy chain this model.*