In the dark, light can be of importance. Darkness not only happens at night, but lurks in nooks and crannies during the day. I always try to have a small flashlight with me, and scarcely a day goes by that I don't need it at least once. A flashlight is great for putting light in a specific place, but less great for area illumination.
A “lantern” is more appropriate for that purpose, but lanterns tend to be fairly big and heavy, which makes them a problem for survival usage, where small and light is critical.
Solar Lanterns: A Possible Alternative
I was intrigued by the concept of a “blow up” solar charged lantern. This would seem to be an answer to the size and power requirements problems encountered with more common lanterns.
Doing some lookup, I found there were actually two (at least) competing versions of this. One from https://www.mpowerd.com/ (Luci) and one from http://sunlightlantern.com/
It appears that these two companies are, or have been, engaged in legal wrangling. Each claims the other stole their idea. Which is right? I don't know; it does not appear that any decision has been made (or at least announced) and at this writing, both are still selling the lights.
The “Luci” company appears to be a bit more stable, with several versions advertised. They have a better list price ($15) and a poor shipping price ($7) if you get only a few (I got mine through Amazon; I was not charged tax). Although Sunlight's list price is $20, when I ordered mine they were on “sale” for $10 or three for $20 (they take PayPal). Shipping on individual lanterns was not bad, $3 total, even if you order three individual lanterns, but if you order the three pack, the shipping would be $8. Still a discount, just not as much a discount.
Sunlight was the winner on price, and arrived first (four business days). Amazon took ten business days. Since the Luci lanterns are not actually shipped by Amazon, the Amazon Prime shipping option was not available. The Luci packaging is a bit more secure, but harder to get into. Both models have the instructions (such as they are) printed on the inside, so be careful when opening.
Luci is 3.8oz, Sunlight is 3.4oz. Both are 5″ in diameter. The Sunlight is 7/8″ thick, with a slight bump at the inflation valve. The Luci is the same, but the valve does not collapse as well, sticking out another 1/2″ at rest. Both have a plastic strap on each end, so it can be hung with the bulbs shining down or up. The Luci has a clear bottom, while the Sunlight has a mirrored bottom.
The Luci is much easier to blow up. Both have valves to keep the air from rushing back out, but that valve also makes it difficult to inflate the Sunlight. It's called a “bite valve”, and if you do bite it (better would be to squeeze it if you have thin fingers) correctly, it is a little easier to blow up the Sunlight but still a challenge. The Sunlight, when fully inflated, has a distortion at the top at the valve location, and seems to leak a bit, and the valve plug does not remain fully seated when casually closed, although if you dry it off and hold in place for a minute, it then tends to stay closed. The Sunlight sides have wrinkles, which are quite visible when not fully inflated (such as after leakage).
Both have 10 LEDs, and a multi-function push button switch. Off, low, high, blink, off. The blinking of both is slightly faster than 1 per second. The Luci, due to the clear bottom, illuminates below the lantern better when hung normally; while the Sunlight, with the mirrored bottom, is slightly better at illuminating to the side when hung upside down. Both come with enough charge to try them out; Sunlight has access to the switch and an invitation to try it on the packaging.
So, based on “apparent quality” and usability, the Luci is in the lead. Based on the claimed specs, price and delivery, the Sunlight appears like it might be a better choice. But specs have been known to be “enhanced”. The only way to tell for sure is to try them.
Step 1, turn both on high to drain them. Luci lasted about 4 hours, Sunlight about 1 hour, but was significantly dimmer (effectively useless) after only 15 minutes or so. This is not a reliable indication of how much of a charge they came with, as I played with them a lot before starting the test. Besides, it is not really a critical factor; either should provide an hour or more of time to check them out, and the wise person would fully charge their lantern before packing or planning to use it anyway.
Step 2, put the Luci in the sun for 8 hours and the Sunlight for 6. Seems unfair, but hey, that is what they claim.
Note, when charging these, deflate them. If they were inflated, it would not effect the charging at all, but the sun could heat the air inside to a damaging pressure, and they would be more subject to being blown away by wind.
Step 3, turn both on high and measure the run time. Epic fail; both were dead in under 7 hours (turned on before bed, they were both dead upon wakening).
Step 4, put both in the sun all day. And a second day, since it is winter and the sun is not at it's most intense. The goal was to fully charge both, for real, not for how long they claimed to take to charge.
Step 5, turn both on low and measure the run time. The Luci ran for 13 hours. The Sunlight ran for about 11 hours before dimming, but continued to shine at the reduced level. I finally gave up tracking it at the 17 hour mark. If fully charged, either would provide light “all night”.
Step 6, once both were drained, put both out for 2 hours when it was cloudy (to see if direct sunlight is needed).
Step 7, turn both on low and measure the run time. Luci about an hour, and Sunlight a bit less, mostly at the dimmed level. The Luci seems a bit better at charging under cloudy conditions.
Step 8, hang each 6′ high in a dark shed, 5 feet from one wall and 10 feet from another. Evaluate the light pattern. The Luci appeared to be “brighter”.
Both of these provide usable light for a reasonable period of time if charged. You might be able to read at up to 4 feet, and perform tasks which are not light intensive out to 8 feet. A little light is visible at the ground 20 feet from the lantern when it is hung 6′ above the ground.
I don't think you can rely on a “full nights” worth of light if only charged during the day; under ideal conditions, it should do it, but conditions are not always ideal. I would say you usually can get a reasonable length of light out of a typical day's charge.
All in all, the Luci seems a better choice, but the Sunlight is adequate, and, at least when I got it, had a better price. If I could have only one, it would be the Luci. Any kit which will fit three or more, I'd have one Sunlight and the rest Luci, since although the Luci appears to be mostly superior, the Sunlight is less costly and provides SOME light for a longer time on a full charge.