If you mean solar charging performance for a solar battery bank - yeah, there isnt much panel on there so they aren’t going to charge quick. A foldable set of panels can get you anywhere from about 15W to 75W, so keep in mind this isnt rapid-charging, never-ending power in the sun.

I have some solar battery banks, I keep them by my windows and rotate through, except for a few connected to low power devices (like some LED strips), which are only drawing about half the wattage at max that the panel can gather during the day, and the battery has plenty to take it through the night.

The ones I rotate through I take for trips out, if I expect to charge my phone and my wife’s (and maybe something for the kids). The reliance during that trip is on the battery, two phones and a random device are going to drain that battery several times as fast as what the panel can charge, so its a bigger bank. It can take several days to charge from solar after that, with good sunlight. Because I have a few of them though, they never touch utility power. Ive had them for the better part of a decade now, and they have held up really well. They are inside when charging so they don’t get too hot (and damage the health of the batteries), and solar charging them helps in that regard as well since its a slower charge than the USB PD I could drive them with off utility power.

The diy community was already mentioned, that would be a good spot if you want to plan a build or something.

Can you explain a bit better what you mean? Like a movable solar panel to charge a phone over usb?

For those it is basically better to charge a usb power-bank at a good sunny spot, at the optimal time and use that charge the phone later.

Also: we have a !diy@slrpnk.net community 👍