Do any small solar chargers (for handheld devices) work?

I was wondering if anyone had experience of a portable, lightweight solar charger that was useful, invaluable even, when out in the wilderness away from power sources. I have a simple one, Solar Monkey I think it’s called, which is quite old now and, whilst it worked a little, was really not much cop at all. But I’m hoping the technology has moved on a bit.

I’ll be kayaking / camping for up to six days away from power, but would like to ensure I keep both my phone and cameras running for the duration. I have a couple of power blocks that I can precharge and they have worked okay in the past, although rather than simply carrying a few more of these (which may prove to be the best option) I’m looking again at the solar angle, see if it’s a goer these days.

Many reviews I’ve read, and even advertising write-ups for products seem to be refreshingly honest about their product’s limitations, noting that they are really power blocks to be charged before leaving and the solar panel is a small top-up extra, but not to be relied upon. Other reviews suggest better performance, but how much better?

So, any advice, experiences, successes or failures you have had with such devices would be good to hear; thanks.

I’ve tested a couple of solar power banks - they generally work moderately well, within the following limitations:

There is a tendency for devices to be labelled dishonestly in terms of their power capacity - especially if you buy from a dropship vendor on eBay
They need to be left in direct, strong sunlight for hours on end to accumulate a worthwhile charge - not always practically possible in a camping situation.

I believe there is a hand-crank charger running off a magneto or dynamo. I have no idea how well it works, but I know of radios and bicycle headlamps that work on that principle.

The Best Portable Solar Panel

I have found the Outdoor Gear Lab reviews to be very useful. They don’t just publish press releases and advertising copy, they actually buy and use the products for extended periods before they publish.

My son took one on the Appalachian Trail last year and was pleased. I don’t know the particular make or model, but the tech seems to be there.

Goal Zero products are fantastic. I own solar panels, LED lights, etc. from them and all are terrific products.

In fact, I have the same panel that is listed as “Editor’s Choice” at Turble’s link. I’ve used it on the dash of my car, on my backpack as I hike and on my kayak as I paddle. It’s well made and works just like you think it will; I’d buy another should the need arise without doing any new comparison shopping.

I have two but haven’t had the chance to use them when camping. Here in the Netherlands in the spring it takes the better part of a week to fully charge them which will then allow me to charge my iPhone once (off of each). In the summer and when pointing the panel directly at the sun this gets much better, but you’re still looking at less than a full charge a day in most reasonable circumstances.

They’re not much bigger than power banks without a solar panel, though, so you can basically use them as one of those. But even one full charge every few days is a lot more than nothing if you really need it.