I'm going to start with the pros and cons, then address a few things because I'm too lazy and ill-equipped to do a lot of testing and picture-taking
Puts out a surprising amount of light in high mode, low is still useful in the immediate area
- High: 65 lumen for 40 minutes
- Low: 15 lumen for 4.5 hours
Reasonably small size for a lantern thing, smaller than the "dalek" (to steal a phrase from bigclivedotcom) style.
While it feels solid enough, I have to question the durability of a $14 wonder light
Micro USB port; it's an increasingly rare thing to use elsewhere, in favor of type-C
No idea how well this thing actually charges a separate USB device
Might be actively dangerous if two devices are plugged in.
Caution!! ¡¡Precaución!! Vorsict!! Mise en garde!! 警告！！ 注意！！Rhybudd !!
These type things have a nasty habit of not being designed to be charged while charging another device, and may in fact deliver mains power straight from the incoming charging port to the outgoing charging port. This may fry your device, and depending on construction (e.g. metal-bodied phones) might well fry you. I've asked the manufacturer for clarification.
I will note, as majorhavoc does below, that a USB charger should be limited to 5v and (depending on spec) no more than 3A. This isn't exactly human-killing levels of electricity. I still would avoid plugging anything into it while it's charging, though, just to avoid any possibility of harm to yourself or your device.
See that ludicrous warning above? I didn't know that when I bought this little doodad, and probably wouldn't've bought it if I'd known. Unfortunately, I don't have a way to test that without risk to myself right now, so I ain't gonna. If I can find a USB extender, a USB-A port should be large enough to safely take my multimeter to.
But hey, let's roll forward with the review of this potential mini-electric-chair anyway.
In flashlight mode, squished down into a puck, this thing is actually a pretty competent flashlight. On bright a fence 40ft away is well-lit, though a tree 100ft away isn't notably lit. On low it'll barely light the fence, but my pecan tree (25ft) is pretty well lit.
Lantern mode is set up by pulling the halves of the puck apart, leaving them connected by an accordion-like tube of some kind of translucent white plastic. Low is sufficient to light even my living room to navigable levels when hung from the ceiling fan, high is enough to read if facing with the text towards the light.
It doesn't have any levelling circuitry: the light's fully bright for about the listed period, then slowly dies. I left it on yesterday starting around 1900, and the LED was still desperately trying to put out light this morning at about 1000.
Charging from an external source (battery, wall, whatever) is via a basic micro-USB connector.
Cranking is a stiff dynamo that folds out of the bottom, with a claimed runtime of 4/11 minutes (high/low) per minute of cranking. This seems pretty spot on, and in fact is one reason I bought the thing.
Overall, seems pretty good. The plastic seems nicely stiff, and is a clean casting. There's a good bit of heft to it, which I attribute to the charging dynamo. The lens plastic is nice and clear, and seems pretty hard (I can't press it in with hand-force). The lantern diffuser is some kind of flexible plastic, and I won't even hazard a guess at the cycle (open-stretch-close) count it'll survive. The power button and port cover are something rubbery, probably the ubiquitous butyl polymer.
If it weren't for the safety concerns, I'd recommend this. While it's primary utility is probably as a lantern it's still a decent flashlight, and I like having at least one device that can be self-charged (just in case). It's not tiny and ultralight, but neither is it a monstrously large or heavy device.
I would like something that's water-sealed (instead of "splash resistant"), but I wouldn't expect that given the price.
I've asked on Amazon how the outgoing port handles current while the device is plugged in. If I get a useful answer I'll update, or if I remember to snag an extender cable so I can check myself.