BigBlue 28W Solar Charger Foldable with Digital Ammeter, Outdoor Solar Powered Charger with IP44 Solar Panels USB-A & USB-C Ports (5V/4A Overall) for iPhone iPad Samsung Galaxy LG and Devices

The bad news: the highest charging current I've had in ideal conditions (Scotland, midsummer, midday sun, clear skies) is only 1.7/1.8A. A long way short of the maximum suggested by the manufacturers. The good news: 1.7A is an extremely useful charging current. The Big Blue can also pump out some solid current on overcast days - close to 1A with light cloud. Obviously really heavy cloud will drop the output to zero. In mixed weather conditions I found it more than capable of keeping phone, headtorch batteries etc charged on an extended camping trip. My phone gets used pretty heavily - photography, news & weather if I can get online, Kindle books etc - so this was a solid performance. I also used a couple of 18650 batteries and a Nitecore F1 charger as a lightweight buffer for the rainy days when I couldn't deploy the panel. On sunny days there's charge to spare to fill up the batteries. The 3 stars for water resistance is just my best guess. The unit seems to cope OK with a smattering of rain but I wouldn't want to get it really soaked. The panels seem to have a waterproof coating but I doubt very much if the main electronics, under the display, are waterproof. Why does water resistance even matter for a solar panel? In showery conditions the Big Blue can gather a lot of useful charge in the bright spells. A fully-waterproof unit could be left out unattended while you get on with something else. That's the bottom line for portable chargers: do they fit seamlessly with daily life in the field or does it feel like device-charging is starting to dominate your time? The Big Blue performs well enough not to be a nuisance. The display is great - indispensable really. If you want to learn how best to use the panel you need to see how well it works in different conditions. I measured the weight at 610g on scales of unknown accuracy. All in all, I like it. May not perform as well as claimed (I didn't really expect it would) but it does perform well.

I love my portable camping solar panels. Have taken them on several hikes in the UK and France and they are great for keeping my devices topped up with power. The fabric is durable and the design is simple to use with two USB ports. It is worth noting that to get the maximum power output you need to use both ports. It will only provide a maximum of 2.0 per port. If works well in both direct sunlight and shade, although the power drops off a lot in the shade. For best output I prop the panels so they are at 90 degrees to the sun if it isn’t directly overhead. I also pair it with a portable battery pack, which I then charge my other devices with. As more devices switch to USB C, I would look for panel with high output on a single port to charge the battery pack faster, but this model will keep an iPhone topped up. I also like the display so that I can adjust the position to maximise output.

The portable solar panel arrived as ordered, I unpackaged the item to see small scratches on the digital ammeter screen, which if it was brand new it shouldn't have. It does not appear to affect the ability to charge and other than that appears to work as described.

Bought this after a smaller one failed to charge my phone. I love that it has an ammeter so it shows the charge going in and works in shady conditions (but at a lower charging rate). Very robust and worked after getting caught out in rain. This meant I was able to keep a mobile phone fully charged without any other electrical means for a week at the IoM TT races

I've had this a month now and have tested it in all sorts of weather. I have to say, although I was worried it wouldn't be too great with the British weather, it has surprised me... a lot! I've provided two examples below of my experiences where the charger was on the dash of my car (on sunny days I folded the output screen under the panels with the windows ajar). I also only charged one item at a time. Very cloudy/rainy day with no direct sunlight: When it first arrived in March, the weather was miserable but I was still able to get a reading of 0.2 to 0.4 amps. So I plugged in an iPhone and it began to charge! However, rather than leave my phone in the car, I plugged in my small power bank and left the panels on the dash of my car. I thought that the windscreen would filter out some of the required rays but I had the same reading in and out of the car. Anyway, I came back to the car that evening after it rained all day and the sun was low in the sky as its still late winter/early spring. The bank was half charged and is 4000mAh, so for pretty much the worst type of weather (no direct sun at all the whole day) for solar and the sun only being low in the sky anyway, I think it did well. I was able to fully charge this bank after two and a half days of this same weather. My 8000mAh power bank never reached full charge and obviously took a longer - 4 days but the 4th was spent stuck at 75 to 100%. Sunny days: Wow. This thing is great in the sun! the maximum output I've achieved is 2.2 amps, and that was on a bright sunny day at the beginning of April. It charged my 4000mAh bank in 3 hours and I've left my 8000mAh bank in the car which was charged completely by the time I'd finished work - I'd left it from 10am where the reading was 1.6, checked it at lunch time and the reading was 1.9 to 2.1 and then in the evening at 5pm when I finished work, the reading dropped to 0.2 with the sun being very low and the angle of my car not being great either. However, the bank was also showing as fully charged. I've also found that the last 15% or so takes way longer to complete, I'm no expert but it just seems like its harder for the solar charger to push in that final bit of charge! On sunny days it will manage but on other days I settle on 90% and switch to another empty bank. It's also worth bearing in mind that I choose to charge power banks still rather than plugging directly into my iPhone because if it takes say a day to charge it and it's still switched on, then you're going to need a sunny day to get it close to 100% because not only are you trying to charge up a 1821mAh battery, but you'll be using half of the supplied power to power the devices wifi/cellular/screen/background processes etc. An iPhone and some other devices also require a minimum amount of amps, so when its cloudy for a while and it's 0.4 on the solar charger, your phone/device might reject this and cut it off. A power bank generally doesn't so this power(although a small amount) is still soaked up. The only thing that does annoy me about this solar charger is that the USB ports are difficult to access from within the pocket - it's not a big deal, maybe something BigBlue can improve on in the next model. Very happy with my purchase.

Werkt uitstekend. Op een wisselend bewolkte dag heb ik 0,3A tot vol in de zon ongeveer 2,7A met soms uitschieters van 3,0A in Nederland. Powerbank van 20.000mA ging van 67% naar 100% in 3 uur tijd vol in de zon (buiten temperatuur 26 graden Celsius).

Eccezionale!!!! Ricarica solare rapidissima che sfrutta ogni seppur debole raggio di sole. Perfetta con la Power bank Charmast Power Bank 26800 mah, di queste power ne ho acquistate due pure qui per non sprecare neppure un raggio di sole. Un prezzo per entrambi, pinnellino e power, irrisorio per una qualità super, approfittando magari di qualche offerta a tempo. Per caricare velocemente anche un cell Redmi Note 14 pro 5 g oppure un tablet lenovo idea tab plus è ideale. In pratica con il pannellino e le due power mi sono emancipata dalla rete elettrica per ricaricare tutti i dispositivi di casa. Entusiasta.

モバイルバッテリーや携帯電話にふつうに充電できました。キャンプの時や災害時にあると安心かも！

I recieved the ild version of the product, not the same as the picture shown. Though very few changes in the updated one but its not right to cheat. Used very few times till now and satisfied with the quality and charging level. More can be said only after using it properly for a trek

Not the lightest but not a big concern since it will be during travel with motorbike. Enough to charge power bank. Nice and easy to fold and very good with zipped pocket for the unit to be charged.