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.

First I tested it in the day time - heavily overcast between bouts of rain. It produced 0.2-0.4 A Then I tested it in the day time with light cloud cover - translucent sun. It produced 0.7-1.2 A Then I tested it on a bright day still with some light cloud cover. It produced 1.8 - 2.2 A It seems to work, though you need to be careful when inserting and removing the USB from the Ammeter because the Ammeter is not strongly attached to the casing. If the ammeter comes loose then it can break the charging circuit since it is in series. My ammeter did break loose on the first day, so I used hot glue to squirt under it and around it in order to secure it firmly. It has a portable size. On the negative side, the ammeter became detached from the case. If it breaks off completely then it will break the charging circuit rendering the product useless. The maximum current on day 1 was 2.2 A - not 5 A as advertised. On days 2 and 3 it seemed fine in mild sunshine. On succeeding days I could not get the current above 0.2A even in bright sunshine, so I guess that the product is broken. It has not been field tested and yet it already is malfunctioning

Received my Ammeter version of the BigBlue 28W Solar Charger the other day from Amazon. Opened the package and straight away I could see that the Ammeter wasn’t attached straight. Then to make matters worse when I checked out the two USB ports rubber covers, they just came away from the Ammeter, as the rubber attachments had already been snapped/broken during manufacturing I guess? Finally, to top it all off, even in direct sunlight I can’t charge anything and the Ammeter won’t go above 0.0 - Absolute Rubbish! I’m not sure if the new textured hard Solar Covers have anything to do with the poor, or actually non-existent charging? I’ve emailed BigBlue directly as per their Warranty Card and they haven’t replied yet, despite their promise to respond within 24hrs. I do have the 3 USB port version as well as this one, which despite it being larger and heavier, it definitely appears better quality and actually charges. Will be returning this one back and writing another snotty email to BigBlue if they don’t respond shortly - Not Happy! (See photos).

Best buy ever. First test at sunny midday in south of UK and I got 3.9 amps from both ports, I couldnt believe my luck. One was 0.6 and one 3.3. I thought the max output on one port is only 2.4 but wrong. Next time only had my powerbank plugged which accepts 5v 3a input and got 3.3 amps like on picture. Thats a fast charge, over 16W of power. Great great panel, probably the best. Also on cloudy days I do get 0.5-1amp of current so 2.5-5W of power, not bad, not much many other panels can pull out any power from cloudy days. Well worth money for it