TOPDC 60W High Efficiency 22% Solar Charger with 5V USB 18V DC Dual Output, with Battery Clamps and Car Charger for Laptop Tablet GPS Cellphone,Car, Portable Solar Power Charger for Camping & Outdoors

This thing is awesome, especially for the price. End of story. Get a DC-barrel to cigarette plug adapter, then a cigarette y-splitter, then two high-amperage (mine are 5 amp) universal 12-24v cigarette Twin-USB plug to maximize your ability to use this thing. The onboard USB charging port only puts out 1 amp worth of charging power, this method will give you 7-10 amps worth of USB charging off of 4 ports in good sunlight. I've been the hero of multiple camping/festival expeditions now.

Be careful and check the voltage polarity on the charging attachments that come with this product. Specifically, the alligator clip charging attachment supplied has negative polarity (red alligator lead should be positive but two units I received both had negative voltage polarity on the red alligator clip). You will fry the solar panels if you hook negative voltage up to the positive terminal of a battery.

This is a very compact unit, I'm replacing a 28W folding unit I carry in a dry box, this still fits in the same space.Good production, initial test produced 38W in overcast sky with less than perfect sun angle. Worked with my Victron MPPT charge controller just fine. It showed 17.5V out at 2A (in overcast). The included cables are of acceptable quality.UPDATE: I tried it out in full sun and it was developing 50W. Good to go.Build quality appears ok. The panels are good and the material seems OK. The one worry is the flimsy zipper on the side pouch. This will be opened and closed many times and I question its long term reliability.The reviewer below is correct about the battery cable polarity, EXCEPT that the SAE connector you use to connect the battery cable polarity is also reversed. SO, if you use both the included 5.5x2.1 to SAE adapter AND the included SAE to alligator cable, the final polarity is correct and safe to use. However, they should have included the proper standard polarity cables.In SAE, a power supplying connector should be positive on the bare conductor. SO out FROM this solar panel should be positive on the bare conductor. This adapter is backwards. Too bad, the alligator clips are nicer than other panels I have.The other cables are all correct polarity.Minus one star for the flimsy zipper and reversed polarity cable.

I was happy to find that the charger would work even though it was not optimal conditions. It charges slower of course but it does work on a cloudy day. Only one complaint and its not a big one. The description above says the item weight is 1.2 pounds, that is not correct, it weighs 1 pound and 15 ounces. Still a 40 watt charger at under 2 pounds is a great find, so I am happy.Update: I tried this even on a cloudy day completely overcast and snowing all day, this panel worked to charge my retevis rte3 walkie and did so directly plugged in via dc current. I do alot of winter camping in snow etc, I use different batteries for camera, headlamp, camp lamp, etc. Using the zanfare C4 smart battery charger I can charge all my batteries with this panel. This is fantastic, the zanfare C4 also has a battery bank function so I dont need to pack an extra battery bank which is heavy. With this panel and the charger I am set for all my camp needs. Charges fast too. I have to say I am impressed with this panel, very happy with it.

It may work well, but I couldn't use it as the adapter for my common HP laptop wasn't there. Seller also gave a very vague idea of where to find some. So, figure about another $15 for more adapters.

Love how small it folds up. Easily can fit in any bag.I bought a DC to USB-C adapter [ https://www.amazon.com/dp/B01FCWLMOI/ref=cm_sw_em_r_mt_dp_gS9vFbN5SQSJT ] and it works for smaller USB Type-C products, but panel is not powerful enough to charge a 16" MacBook Pro directly, but get a power bank that can accept solar DC input, and output USB Type C PD like this product: [ https://www.amazon.com/dp/B072JWN6LC/ref=cm_sw_em_r_mt_dp_JT9vFbF00GBGF ]

The panels provide plenty of power to charge my phone and laptop simultaneously while in use. Exactly what I needed for a week long scout camp.

We used this for a month on summer vacation. We relief on this panel. No electricity. We used it to charge 100 Watt portable battery as well as cellphone, tablets and small power bank.Very light and portable but very durable.On shady days it did not put out enough power to charge the 100 Watt battery but it could still charge tablets, small power and cellphone.If the sun was out and you didn't put it in the direct sunlight, it could still charge the 100 Watt portable battery.