How long does it takes to recharge the battery using only the solar panel?
Per the vendor: Full recharge through solar panel needs 24 hours of strong sun light.
Walmart’s site actually has a few more pictures that are helpful: https://www.walmart.com/ip/Zunammy-ZBank-12000mAh-Solar-Power-Bank-Battery-Charger-with-Flashlight/236325421
24 hours for a full charge? Not what I would call “high speed.”
While I doubt it will be anywhere near that fast with full sun solar- that is SOLAR charging - you can plug it in like all other non solar powered battery units to swiftly charge
12000-mAh = 12-Ah. That’s the amount of current generated by the typical automotive battery charger sold for home garage use. There’s no way that this toy can produce that amount of current.
It’s the batteries capacity, not output… but I was curious about the USB output is it 1amp or 2amp
Wanted to get one of these, however Woot only delivers to the US, so what’s the point of inviting me to join?
The Walmart pictures provide some information, though possibly conflicting.
The back image, https://www.walmart.com/ip/Zunammy-ZBank-12000mAh-Solar-Power-Bank-Battery-Charger-with-Flashlight/236325421 has the following:
- Input 5.0V/1.0A
- Output: 5.0V/1.0A,2.1A
The label on the front https://www.walmart.com/ip/Zunammy-ZBank-12000mAh-Solar-Power-Bank-Battery-Charger-with-Flashlight/236325421 has all sorts of technical information:
- Capacity: 12000mah (sic)
- Solar panel 5V, 200mA
- LED Power: 2.4W
- Input DC 5V/1A
- Output DC 5V2X 1A
Optimistically, it’s one 1.0A port and one 2.1A port. A pessimist would go by the back and assume it’s 2x 1.0A ports.
If the solar panel is indeed 200mA at 5V, which seems reasonable for the size, it would take WAY more than 24 hours to charge.
12000 mAh / 200ma = 60 hours. If you convert from 5V to the 3.7 V the battery uses and the 12000mAh rating most likely uses, you get 60 * 3.7 / 5 = 44.4 hours.
With an optimistic 10% voltage conversion penalty, you get 44.4 *(1.10) = 48.84 hours.
That’s over 2 days, and doesn’t even taken into account charging inefficiencies less than ideal solar exposure–clouds, misaiming, and the like.
And, unless you’re near the north pole in summer, there’s this pesky problem that the sun goes down every night.
It would likely take 4 days or more to get 48 hours of direct sunlight to the panel.
If you could put the charger out in the sun on a cloudless day and reorient it a couple of times, you might get 8 hours of full strength charging. That’s 200mA * 8h * 5V / 3.7V = 2162mAh. If you hang it from the included carabiner on your backpack, you’d be lucky to get half that.
So you could maybe plan on getting 1000mAh of charge every sunny day.
That’s about half an iPhone charge.
Conclusion: the solar isn’t worth much on a daily basis, though it would allow you to revive a dead phone to make an emergency call, which could save your life. And at $15, you aren’t really paying extra for it.
Otherwise, the 6-LED light looks pretty useful. If it does indeed have a 2.1A output, then it could be worthwhile.
If it is 4.9” x 1.1” x 7.4”, then it’s huge, and likely pretty heavy.
I won’t be buying one, but you could certainly do worse.
Output is not measured in amperes. Amps/time is output.
It is a high speed charger, meaning it charges other devices at high speed not that it can be charged at high speed. at least that is how I understand it.
LOL!
the math makes my head hurt, it’s been 15 years since my physics class.
anyone find a review anywhere?
if it holds 3-6 charges, then a slow solar recharge isn’t terrible.
its more than enough for 3-4 day camps and hikes to keep the music playing and a kindle readable.
it’ll recharge about 1 phone’s worth per sunny day, if i read that maths right?
might use 1.5 charges on your phone and half a charge on a tablet per day camping?
you’ll be running dry by day 4, which is pretty good.
sounds almost too good.
I owned one of these. No way you’re getting 6 full phone charges off of one battery. The solar is a bit of a ploy, it’s way too small a panel to get a lot of charge. 24 hours of direct sunlight is a stretch - I’ve kept it out for hours and gotten like 2-3%. That said, it’s a welcome 2-3% if you’re in danger of being without electronics.
This battery - with case and solar - is about as thick as a deck of cards and a bit larger than some of the larger cell phones on the market. Not big enough for 12,000 mAh.
how can you tell when it’s fully charged? does it give you any indication ?
So this item is optimized for use in Alaska?
Only if you have it shipped outside Alaska first and then drive it there.