SunCat batteries boast built-in solar charging wrappers
By Darren Murph 
posted February 27th 2009 8:11AM
posted February 27th 2009 8:11AM
[Via Inhabitat, thanks Sarvesh]
posted February 27th 2009 8:11AM
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i want one
I'd be concerned about how the heat from sunlight affects the batteries themselves...
Ditto. I wonder if the sun's heat would mean any risk of them exploding or wearing down the life of the battery itself.
Most rechargeables I've used get pretty hot when charging, so I doubt a little extra heat from the sun will do any harm :)
I wonder how these will get sunlight when they are tucked away inside my gadget. It's not charge and play since you still have to take out the batteries and put them in sunlight. Might as well walk with a charger since you won't have time to sit and wait until sunlight charges these. Not really practical.
transparant battery covers? i duno might ruin the look of the gadget if say it was all black then a see through panel=/
considering most gadgets have batteries on the bottom of the thing, you might need transparent EVERYTHING for this to work
just throw them out the window! fuck!
Gets my vote.
Presuming they can be made robust enough not to break off after a few wrap/unwrap cycles, and can be proven to be 'greener' overall than a normal rechargeable cell...
You aren't dumb for not thinking of it--it's the idea that's dumb! At any given time, most of the cells won't be facing a light source and will thus be wasted. Even those that face a light will almost all not be at an optimum angle. Unless the cells cost virtually nothing, only a flat panel charger makes sense.
Oh Noes! I'll have to put them on my WINDOWSILL to charge? Aiiee!
So what if they might have to sit in the window a little longer to charge. The idea is brilliant for its simplicity because the average person needs stuff to be simple.
The idea isnt that bad, its just poorly thought out.
What he should do is put a AA battery in there and use the free space for circuitry to better charge them. A smart charging circuit and capacitor would do a lot more than this trickle charge. It would fill the capacitor and then push that out to the battery. I believe LiOn batteries dont do well with trickles.
Regardless, this idea is really limited to camping and other outdoors activities. In the city I prefer these:
http://www.thinkgeek.com/homeoffice/gear/8e82/
Can I be a news seeker with you guys? I seen this over two weeks ago...
SAW!
http://web2.uvcs.uvic.ca/elc/StudyZone/410/grammar/ppvpast.htm
Anyone can contribute news by visiting http://www.engadget.com/contact/tips/
In other words: I don't think you would make a good news seeker - you waited 2 weeks.
"saw" is not correct. Perfect tense, or "had seen", is required as the subject of the sentence is not on the act of having seen; rather, it is on the consequence of the act.
http://en.wikipedia.org/wiki/Perfect_tense
HMM question .Isnt leaving batteries in the sun dangerous though?
This is so solar. Better build in a small generator and roll them down a hill.
F-ing BRILLIANT!!
They must cost a mint though.
This is the single lamest thing I saw in a long time!
And no its not a good idea!
That's a bad engadget, Bad engadget, Bad! No!
notice he said it was for "trickle charging." This design could not possibly provide enough power to charge a cell from scratch, only keep it from losing its charge as it sits there waiting to be used. Since that's my gripe with rechargeable batteries, this may have a market if you could make it affordable.
Or you could just use an Eneloop or similar NiMH battery that has the self life of an alkaline. While this project looks completely awesome, it is completely useless, and a waste of perfectly good solar cells.
All portable device would now have to have clear, translucent battery covers.
Leaving the batteries in sunlight might not be dangerous if the solar cell is converting the heat into energy. Perhaps when they are fully charged, I don't really know. My guess is it's not that dangerous. They could be designed with thermal insulation and to bleed heat when fully charged with some sort of heatpipe setup. It's not an impossible problem.
As for most of the cells not facing the sun, that could be the design, as solar cells are becoming cheap enough for it not to be an issue, or, if it were an issue the battery could be designed with a low center of gravity on one of the sides so that it would always rest solar side up. Another solution is to have a plastic charging bay which would allow people to set the batteries for charging. I would just design them to roll into place like bad dice though.
Overall a brilliant and simple idea, which I only see one potential problem with, charging times. But since the sun can give up to 1000w per square meter, this might not even be an issue for a small battery.
Does his method for faster charging involve superman flying the batteries really close to the sun? because I gotta tell you, the batteries may be cheap but superman is a pricey sob.
Wrap one of these solar charging wrappers around each of your fingers, wire it to your cellphone or ipod then charge them as you walk, drive or ride.
Just don't wear gloves or stick your hands in your pockets.
There appears to be many solar panel chargers, but why aren't roofs covered with this stuff? Mailboxes, streetlights, cars, hats... etc.
A few years a go, I read about a solar paint that was conductive - you could paint a roof and garner power from it. What happened?
Maybe there is a conspiracy going on.
No, it's just not cost-effective unless you have a low-powered device that absolutely has to be off the grid.
exactly how long would it take to charge, would it like charging the {Moon Stone} Sun Stone in Chrono Trigger?:
http://www.youtube.com/watch?v=lVZL5WWMBQo
if NiMH C-size batteries didn't lose their charge it would take ~280 days to charge one (based on a 5% efficiency {pessimistic}, 70days would be optimistic at 20% efficiency) from my crappy understanding of math based off of an: Average over the entire earth = 164 Watts per square meter over a 24 hour day (I don't know if this figure is correct)
C-size batteries have dimensions of h=50mm, and a d=26.2
Nihm for C-size have about 2500mAH at 1.2V
thin film solar cells have an efficiency of ~20%
The self-discharge for NiHM cells is 5-10% on the first day, and stabilizes around 0.5-1% per day at room temperature, so if you take that into account the best you can do is keep the batteries from losing their charge
Put them in a clear-case flashlight in your window and you're always good to go.
So that when the power goes out... you can light the few corners not lit by the sun coming through the window in which you flashlight sat?
Or just buy a solar-charging flashlight with better efficiency and form factor.
Leave it on the windowsill to charge, use it when it's dark out.
This would have been awesome back in the 90's when I used to run out of juice playing my gameboy, and would leave the batteries in the sun...to only get an extra 10 mins or so :)
I heart gizmag.
If you have the time to pull these out of your enclosed device (game, player, etc) and stick them faceup towards the sun why don't you just stick them in the charger?
You wont get enough power to charge these things in a reasonable amount of time and if you did, why dont you just get a device that has that kind of amperage solar panel hooked directly up to it... I remember when the solar power calculators were all the rage, because people didn't feel like dealing with the batteries in the first place. Specialized capacitors and solar panels make more sense, charging will be faster too...
first off, the idea is that you wouldn't need a charger. You could be in the middle of no-where (Sahara desert, arctic tundra, et cetera) and all you'd need to do is pull the batteries out and they'll recharge. It means there is one less device needed in this process.
Secondly, it is a prototype. Prototypes are there to demonstrate the idea. it really isn't all that often that the first prototype has the capacity to fully accomplish what it is supposed to do.
Assuming one could improve the efficiency, this'd be good for camping, wunnit? Leave 'em out during the day, pop 'em in at night fully charged.
Obviously, a better application would be a solar flashlight; hold your durrs and your hurrs, folks. Recharge whatever sort of rechargeable battery you please inside, with more efficient, stable solar cells on the outside of the flashlight. This solves the problem of batteries wearing down over time, no need to add to the cost of the battery with solar cells.
Hate to poo-poo this idea but I will :)
Ni-MH and Lithium Ion rechargeable batteries - even the latest whizz-bang technology from Sanyo (Eneloop) - do not like heat. In fact, self-discharge increases a lot the more you heat these things up and who knows what it does to longevity. It can't be good.
Now you can say that a charger heats them up too. Yep, it does (fast chargers of 2 hours or so are notorious for this, so avoid them), but not to the level of a dark-ish battery being left in the sun for hours / days (which is needed for this idea to charge the batteries with current tech).
Poo-Poo 2:
----------------
When the batteries eventually die, the lovely solar cells get disposed of, too. Not good. How will this affect recycling?
More practical solution
------------
If you must use solar, placing the batteries in a charger with a larger solar cell on top (and inside the charger, away from direct heat from the sun) is the ideal, really. The charge can be controlled properly with electronics and the solution is far more practical, and no solar cells really need to be thrown out (and/or recycled) when the batteries reach the end of their useful charge life.
neat idea... any protection from over charging?
heheh... overcharging...
1. Invent it for double A batteries
2. Insert into old GameBoy
3. Play for ever because sun charges while playing...oh wait...the cover blocks the sun... fail?
Awesome. Such a simple idea, why hasn't this been a) invented earlier and b) marketed? Hope it happens soon.
Wouldn't a solar battery charger be more 1)efficient; 2)eco-friendly?
Engadget has acknowledged me. My life has a new meaning.
Actually, Darren Murph acknowledged you, so...yeah...wouldn't brag about that one so much.
"C-size batteries have dimensions of h=50mm, and a d=26.2
Nihm for C-size have about 2500mAH at 1.2V
thin film solar cells have an efficiency of ~20% "
its worse. real C size = 5000-6000 mAh
so its really even more impractical. the cheapie c/d rechargables are no more than cases with AA inside.
heat does damage batteries. 15 minute chargers use fans to keep batteries cool. direct sunlight on a bright day would bake the cells. there might be reverse current flow as well:P