Foldable Solar Panel Charger 21W Folding Solar Panel USB + DC Output ELEGEEK Solar Charger with Adjustable Stand and Zipper Storage Bag for Cellphone iPad Gopro Camera Car Battery Emergency

I think this size is the max size for bring it solar charger casually...It gives 12V charging out put(direct solar out) and USB out.To charge 12V battery you should use solar charge controller becausethis one won't have any of such charging controller but it's not that big currentso that you can use it for short time to charge 12V.I also bought this charge controller, Instapark INCC1205 12V / 5A Waterproof PWM Solar Charge Controller It's not expensive but works well as PWM charger, very reasonable, good combination of this smallportable solar panel.On the other hand, USB out is quite good though, when partially clouded while charging, and when the shade gone,charging amperage won't come back fully. It comes back but not fully....that's my concern. Probably internal inductor charging isn't catch up to be charged higher than it's draining rate.. when pulling off the load, and put back again, then it charges with fully available power.

it does what its suppose to do. I have yet to figure out if this is a fast charger or not.Pros:perfect size to attached to any backpack.lightweight and durable.Consno battery to charge goes straight to the device and once the sun goes down bam no more power.

I really like this item. This solar panel has a great foldup design, is lightweight, and the loops and hooks are actually extremely useful for hanging the panels vertically to capture sun. I bought it because of its DC port that connects to a portable, 3.3 lb lithium battery with inverter (AMSU portable solar generator) that I also bought on Amazon, though the 21w capacity of the panel is small and required several days of winter sun to charge. No problem charging cell phone. Appears to be of very sturdy quality.

I purchased this to charge small devices (especially power banks) while hiking and traveling. It recharged a 10,000 Mah power bank in about 9 to 10 hours of direct sun. And it’s lightweight, small and packable. Very nice purchase.

I use this every day to charge all sorts of devices.It has 2 usb power outputs so I can charge my phone and my power bank at the same time.

Works as expected

I keep it on my dash while I'm driving during daylight and charge my Besiter power bank using both outputs. It works impressively well!