Project by Knut Karlsen

At home i always have some batteries lying around, either rechargeable or normal ones. Usually they are empty, but i'd like them to be always fully charged. I could use a normal charger and there is a lot of solar devices that charge rechargeable batteries. I wanted it simpler; why hasn't anyone made a battery with integrated solar cells? The idea of the "SunCat" batteries where born. The batteries should just bask in the sun like a cat and left for a while, in a sunny window, they would slowly recharge.
Prototypes
During my research for my diploma i was in touch with scientists at IFE that experimented with the production of flexible solar cells. They where kind enough to send me some samples in the right dimensions that i could use for the prototypes (full set at flickr):

I had some older NiMH rechargeable batteries that i glued the flexible Photo Voltaic (PV) cells onto. The PV cells are rated at 1.8V and the batteries are 1.5V so they match quite well.

Half glued you can see the really shiny polymer substrate backside of the PV cell. The crude written text says: 3x0,6V B: 13.411.09 Which i guess is the voltage and a batch number.


Using a conductive silver pen and some flat wires from a broken canon lens I made an ok connection to the PV cell.
This setup is infact a (quite weak) trickle charger. It is not ideal, but really convenient. A second version would have some electronics (to check when full) and capacitors to charge the batteries more efficiently, but the battery would then be smaller if it all needs to fit within a C-cell battery.

The sun did not shine today, infact it was snowing. But i'll sure let them hang around in my window and take some more pictures when the sun shines.

57 comments:
rett og slett fantastisk.
Takk for entusiasmen!
Det lyder som en rigtig god ide :) Det kan du garanteret tjene en masse penge på
Hilsen Johannes fra Danmark
Hi .. thats quite stupid.. cause u dont want the batteries to get hot.. and if u place them in the sun to charge.. well they will get pretty hot...
but nice design though.
Very interesting
trackbacks http://www.fusher.be
very cool idea.
Great idea. On the slow charging - there are many applications where a couple of weeks to charge would be fine. For example, I have 2 NiMH batteries in my mouse. I bought a 4-pack with a recharger and swap dead for live every couple of weeks. We also have a bunch of kids toys that only require new batteries every couple of months.
just brilliant!!!! all batteries should be so equipped!
This is a miraculous discovery! Keep it up!
Ja, det er virkelig helt utrolig bra, det greiene her Knut. Og all rave´n som har kommet på nettet... Dritmorsomt!
Yup, det er artig! Takker til alle!
I want to buy it !
http://wild-wild-web.blogspot.com/2009/02/fini-lere-des-piles-kleenex.html
awesome! thanks!
scott
http://www.solarfeeds.com
Yes, please! This is exactly what we have been waiting for and looking for!
hi,
for say the trouth your idea is not as fantastic as many people think.
1. failure: when you wrap the solar panel around the battery you'll never use all the panels area, unless you place a mirror on the other side.
2. failure: why put the solar panel on the battery??? if you have lot of batteries it is much better to separate the solarpanel from the batteries so you don't have to buy (and manufacture) lot of solarpanels.
and the lifetimecycle of a battery is much shorter than the lifetime of a solarpanel.
if the battery once is cunsumed??? you gonna throw away lots of working solarpanels????
3.failure:
do you really think that batteries like it to lay in the sun????
verdict:
it is much much better to have an external solarpanel.
it is cheaper, easier to produce, much more ecologic because you have to manufacture just one solarpanel to load as much batteries you want.
your idea seems to be practic, but it doesn't make any sense regarding ecological issues...
Great work, and truly a simple solution!
On behalf of the sceptic, i can only say that this looks like phase one, a prototype! And that is really important to realize. I dont think most of todays brilliant inventions came out clean, directly from the drawing table.
This will need some development. But it is a great idea!
Dear Anonym who said "FAILURE" "FAILURE" "FAILURE".
You have resolved to be a critic instead of a dreamer. Ever wonder why people don't like being around you?
Superb idea. There is something to be said for that ignore-until-needed approach.
And they're not neccesarily required to rest in the hottest, brightest sunlight available. Exactly because they're never going to be the quickest rechargers anyway. But then they'll always be full ...
Construction-wise they're probably going to be a bit pricey. But I really like your way of thinking.
good point on it not being a good idea to wrap solar cells around the batteries. Not only would it be super-expensive to produce, but solar cells don't really go bad like rechargable batteries eventually will. So you'll be throwing away all of these perfectly good working solar cells. The external solar cells are less pretty, but are probably a lot more efficient.
Love the concept! Would it be possible to convert old rechargeable batteries to operate like this? You could sell kits even.
I'm also picturing something like a small tube lined with reflective film on the inside to allow light reflection all the way around the cell for faster charging. You'd need some sort of ventilation to keep the battery cool enough though.
I am so glad I found you. I'm based in Haiti, West Indies, and we're totally dependent upon sporadic electricity and carcinogenic crude oil. Blessings upon your brain cells, your article is great. I've been living here for 3 months now, and I'm starting an NGO dedicated to solar energy. How can we distribute your products through our schools and churches? Thanks. Cheers. Claude-Michel, http://www.synchronium.com, cm@synchronium.com, 011 509 3770 1904, Skype ID: claude_michel_prevost. Cheers.
I have read your article with interest and am very impressed by some of the ideas.
Although, as mentioned before, how will you ensure the batteries consumer maximum sun if they are circular? Also the initial costs of solar power technology may outweigh the benefits of having solar powered batteries. Perhaps an external single panel will ensure maximum surface area contact and power?
The initial ideas seem promising, have you perhaps considered solar powered mobile phones, laptops or even mp3's? perhaps more adaptable docking stations for either of these will give an energy efficient greener way to charge our modern day necessities.
Failure, I dont think so, but as a prototype brilliant.
Lets examine what people said:
1. you'll never use all the panels area, unless you place a mirror on the other side.
- Very easy to overcome, however the inventor pointed out they do charge, so this works. The newer solar cells also charge in some shade (ie. the backside of the battery.)
2. why put the solar panel on the battery, they will be thrown out.
-Most consumers will not spend $29.99 -$100 and up on a solar charger but they will spend up to $10 on rechargeable batteries. Does the solar skin have to be thrown away...nope. If you look at various battery adapters that have come about over the years, it wouldn't be hard to build a reusable solar skin that say held 3 or 4 "AA" batteries in a "C" or "D" sized case. http://www.reuk.co.uk/C-and-D-sized-Rechargeable-Batteries.htm
3. The batteries will heat up....people we are talking about maybe 80-90 degrees F. I have batteries traditionally charging on my counter in direct sunlight...no adverse effect.
4. Not ecological hmm. If every battery sold had this capability and they were cheap enough. We would have less batteries in the landfills.
They were all good points..however they are just food for thought for perfecting this idea.
Don't stop...you are on to something.
Verkar vara en bra ide speciellt om man är ute i obygden,slipper ju laddare som e bulkiga och kan falera.
Får väl ha med ett extra för backup.
PJ
I really like the kind of thinking that led to this idea, but I'm sure you need to think harder. Because, even though it's nice, it's NOT a good idea. The "failure, failure, failure" message is a bit harsh, but it IS based on true facts:
1. The solar panels aren't optimally used.
2. Batteries should NOT be lying around in the sun.
3. You're wasting the solar panels, once the batteries are dead.
However, this was only the first prototype. Who knows what the end result might be... Keep going on this path, Knut, because there certainly must be a solution for those three issues!
Only use 3/4 of the circumference with solar panel. The remaining quarter that is not illuminated that well could be used for the label “the cat power battery” (and flattened, so that the battery won’t roll around). It could also possible to print such cells right onto the batteries. The newer battery generations are also less affected by the heat.
And one last thought: how about distributing it as set. It is not necessary to tape the panels on the batteries. Why cannot “I” choose where to put it? For example on the back of my TV remote control. Than the control can lie in the sun for an afternoon, and in the evening it will allow me to switch off the damn thing.
The world does not suffer from a lack of resources, but from a lack of mind… you are on the right track there man…
@13:37 "Why cannot “I” choose where to put it? For example on the back of my TV remote control." Brilliant idea!
Thats a smart idea !
Very nice idea! Super!
Veldig spennende idé! Jeg lurer på hvem jeg kan kontakte hvis jeg vil få tak i de solcellene du bruker. Studerer Design & Innovation på Danmarks Tekniske Universitet, og skriver masteroppgave nå, om smarte tekstiler. Og vil gjerne prøve å bruke de fleksible solcellene til å gi strøm du lys i et stoff. På forhånd takk for hjelpen.
Add a mirrored parabolic dish with a acrylic shelf at mid height. Placing the batteries on the shelf will get light reflected almost all the way around and probably shorten the recharge time significantly!
Your idea is brilliant. I hope you looked into international design patents before publishing.
you could use something like this to house a smaller battery and capacitor and smart sensor.
http://gadget.brando.com.hk/prod_detail.php?prod_id=00390
Great idea, no so much for charging them but more for keeping them charged. All rechargable batteries suffer from self discharge. A small solar panel (maybe it would be even enough to use a panel covering only a 1/4 of the surface of the battery) could counter act this. No need to keep them in direct sunlight either. my solor powered calculator also works in the shadow or artificial light.
no one has addressed some of the more fundamental problems with this design. Who cares if the cells aren't all exposed, that's the least of your problems. First off, that's a 1.5V battery, and you're claiming to have a 6V solar cell, which it may be, but who knows. If it is, connecting 6V to a 1.5V battery for extended period of time, IN the SUN, could literally have explosive results. However, I doubt you'd ever get that far, because as soon as there's no sun light, and the solar cells are lower than the battery voltage, you're going to be putting charge from the battery back into the solar cells! Which will be the end of the solar cells. This is a simple fix though, just add a diode at the positive terminal from the solar cell to the battery. I'm guessing you're initial test didn't work? But keep trying....
Please provide data.
Batteries don't like heat - therefore unless you're charging them in the sun in a very cold environment this won't work. Believe me I know, its my job to test battery charging circuitry.
Colin: you are mistaken; there are 3 cells each of 0.6V = 1.8V total. OP is also mistaken; rechargeable cell voltages are more like 1.2V not 1.5V. 1.8 is still a good charging voltage tho. A shottky diode at low currents will use less than 0.3V if chosen with care. SMT variants can be almost microscopic.
ok man pero, wala man baligya sa amo.
Hello, Knut!
I am a journalist from Russian news agency www.infox.ru. Could we use your pictures for our article?
Please, write to pkotlyar@infox.ru
Absolutely terrific. I am posting this on my blog www.beyondrealtime.com. Wonderful creativity here!!
old idea. these have been in use for years, and we had a D cell with solar window in the mil years ago.
I think this idea is already in patent, for I remember using similar D batteries with half solar window some time ago.
Very nice idea. Could you please contact me. I would like to buy some battery. Can you please contact me at infoatcsraeedotit?
Thanks
miehahhahahha
mypchack.blogspot.com
Perhaps you should reduce the solar panel by half for cost saving because it is never utilized 100%. I think 75% is maxium.
Good idea, perhaps a solar panel sleeve that can be reused would solve the problem of disposing of the panels when the battery becomes redundant. Just a thought.
Could you put cells on only the top and weight the bottom so they would roll to expose the cells?
why not simply make "sleeves" in various sizes for "AA" "AAA" "C" "D" sizes with a spring loaded clip on either end to make contact with the + & - terminals of the battery? then when you want to use the batteries simply slide them out of the sleeves and use them knowing they haven't self discharged. The diode is definately a good idea acting to prevent the battery from discharging in the darkness... great idea tho
Where can I get those flexible solar panels from? I would like to buy some!
keren abis
mantep tenan
i like it
Thanks for given this information about solar rechargable batteries.
do you know some about laptop battery ?where can i to get it?
VGP-BPS8
""""""Add a mirrored parabolic dish with a acrylic shelf at mid height. Placing the batteries on the shelf will get light reflected almost all the way around and probably shorten the recharge time significantly!""""""
You can get the batteries cooked too. I guess you have seen what those parabolic things can do. I once made a parabolic oven with a sun shade for the car and the thermometer raised to 80ºC!! Even if the parabolic design was far from perfect.
Hi, this is wonderful! But i want it, where shopping this cell?
Thank you too.
thie idea is so simple and brilliant that i cant figure out why nobody figured it out untill now. great job, and keep it up.
Very nice idea!
I wrote a blog post to point people to this page (http://www.interwebmojo.com/blog/?p=27).
Congrats! :)
Pickle
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