Solar power?

[cmaylodm]

Are there any affordable solar powered methods of charging Li-Ion batteries out there? I was browsing DealExtreme and they have a 5.5v 1000mAh solar powered self-charging lithium ion cell, which got me thinking: What happens to all my rechargable lights when the power goes out? It would be great if there was a way to recharge lights using solar power, that way I could conserve primaries until they are absolutely necessary. Perhaps there is a way to output 12v/450mA to my Ultrafire WF-139 charger?

 

[Eugene]

Get a small panel, a small charge controller and a small 12v gel cell, then get a 12v in charger for your Li-Ion's. The solar/controller/gelcell sit all day long charging and then if you want to recharge a flashlight battery you just drop it in the charger. The gel cell will hold a charge for a long time if you size it properly. I'm looking at doing this on a larger scale, I want to get a couple hundred watt panel and controller and a nice big battery the size of a car battery then power my battery chargers, cell phone charger, etc from it.
Solar charge controller can be bought with a low voltage drop out which normally disconnects the load from the battery but I plan to use it to switch a relay that will turn on a charger powered from house electricity to charge up the battery should I run out of sunlight long enough to let the battery discharge. Then monitor to make sure I'm not switching to electricity too often otherwise I need to add more panels. Only reason I don't have it running now is the price of the panels went up a lot since I planned everything out so I have to save up some more.

 

[VidPro]

i find that excessive conversion is a waste of the all to limited solar power.
if you have the skill, make your pannels 6V and use a simplistic voltage regulation to lock the max voltage.
because the Current not the voltage goes to heck when the sunlight is limited, you only have to go over the voltage a bit.

using methods like that, i get 2X the charging by using the power more direct, vrses converting it to death. after all its already DC .

i suppose its like everything, the further off the stuff is originally, the more you lose trying to get to where you want.

 

[Eugene]

Where do you find battery chargers for Li-Ion or NiMH that take 6v in? Unless you build them your self 12v will let you use an number of automotive accessories and the majority of panels you can buy are all designed for 12v charge controllers.

 

[VidPro]

Where do you find battery chargers for Li-Ion or NiMH that take 6v in? Unless you build them your self 12v will let you use an number of automotive accessories and the majority of panels you can buy are all designed for 12v charge controllers.

Yup , if you want it done right
i was just indicating that charging a 4.2V battery from a 6V source, with say some 1.2V loss is very efficient.

there is tons of accessories that are already 12V, and tons of pannels designed to charge 12V battereis, but these accessory items are designed for cars, and LOSS isnt even a concideration.
when i started doing solar, the first thing you realise is they suck max out at mabey 14% efficiency with Bright Well Aimed sun.
then all the CRUD they were tossing between, like even the CHEAP diodes they would use, instead of shotkeys or mosfets, they were squandering away lots of the power in inefficency.

so when i made up my li-ion charger, i wasnt going to have 2X the pannel and blow 50% of it.

 

[Eugene]

Thats why I never use inverters and suggest not using them as well, they have to be 80% efficient or better to get an energy star rating and I've never seen one with that rating on it.
I've been planning on building a couple chargers of my own, keep looking through different data sheets. Those are pretty much as efficient at 12v in as they are at 6v in but running everything from 12v means I don't have to reverse engineer my cell phone charger every two years when I get a new on or disassemble my linksys router to see if it can run on less than 12v.

 

[VidPro]

we tested 110-120v inverters here, and they were way inefficent, just turning some of them on and NOT using the power would suck the poor thing dry.
i think that is WHY there is so much 12V stuff out there for "SOLAR" .
i always say the first thing you learn about applying solar is just how much energy you were using/wasting

on the other hand, one FULL house solar story i was reading, was from a person who was just trying to save MONEY, he did his full conversion, and between his kids and him it only provides them 1/3 thier total power.
poor guy needs some LEDs

 

[VidPro]

the thing at dealextreeme is a solar cellphone USB type of charger, i do not THINK it contains or uses a li-ion rechargable itself.
its probably a regulated 5V output solar charge system, you could plug a nokia, or PDA or whatever into. so you can charge a li-ion with the appropriate 5V adapter thing.

they DO have ones (in existance) with ni-mhy and 2X li-ion (so it can be regulated to 5v) , that do have internal battery storage, and the same basic USB 5V power output available on places like e-bay. this one just does not look like one of them.

only the title seems to be mismarked at the moment, and they admit they dont have data on it yet.