Posted by admin on Monday Jan 31, 2011
Filed under :12v Solar Charger
Im building a solar powered USB charger and im using a DC-DC converter to get down to the required 5VDC for the USB charger. I have 6 cells in series with a compined open voltage of around 20 volts but when I connect them to the DC converter the voltage drops to 6VDC In. The converter is a VB1205S and is rated at 1 watt. When I connected everything up to a 12V AGM battery the USB setup was charging an older mp3 player fine.
I just checked it again with the 12V agm battery and it charges the mp3 player fine.
Ah I forgot to add that the converter is rated at 9v to 18v in but even with less cells (4 instead of 6) I should have had enough voltage to be within that range. I did that first with 4 cells then added the additional 2.
Ok I think you guys are confused so ill type slower
All of the CELLS in SERIES are 20+ volts OPEN voltage….When I connect them to the converter it drops to 6V at the INPUTS. These arent panels…they are CELLS and are rated at 4.5V OPEN VOLTAGE each.
If these CELLS have an open voltage of 20V +/- why does the INPUT voltage drop to 6V when they are connected to the INPUT of the converter?
Im even going to make it easier….I have a YouTube video of the project….so if you have a few minutes please take a look at the video.
Posted by admin on Sunday Jan 30, 2011
Filed under :12v Solar Panels
I want to make 12V 4.5A solar panel to charge my battery used in my RC car project. I just like to know how should I amplify the current for 4.5A. I need the total circuit diagram. Can anyone help me. Please. I need some affordable methods please.
This will be hooked up to my solar panel batteries in the basement. The battery output is continuously 12v. I’m planning on connecting all my phones to my batteries in time. I also have a trickle charger active on standby if the voltage gets too low to keep the batteries at 12v when I have no sun. My solar panels are about 105 watts in total and they also have a charge controller. I have 5 large wheel chair batteries for power.
Posted by admin on Tuesday Jan 25, 2011
Filed under :12v Solar Panels
I live in Southern California, and I have been considering solar panels for some time. I’d love to air condition my house, but I’m not willing to do so until and unless we come up with an alternative energy source. I’m somewhat anxious to go ahead with the solar idea. It seems, though, that the technology is changing rapidly. I wonder if it would be smarter to wait.
Posted by admin on Monday Jan 24, 2011
Filed under :12v Solar Charger
I have a 12v, 5w solar panel that I typically get 8-19 volts out of with current between 30-200ma depending upon conditions. I would like to use it to charge an electric razor. The charger on the razor is outputs 6vdc at 150ma. And it’s a li-on battery within the razor.
Can I just attach the solar panel directly to the charger (cut off AC plug so it’s just wire leads attaching to alligator clips off the solar panel) and let it charge the battery for say 5 hours when current off the panel is around 150ma or less and about voltage in the neighborhood of 15 to 18v?
I don’t have a charge controller and want to make sure the li-on battery doesn’t overcharge or explode. I know they’re more prone to this than nicad or ni-mh batteries. And that’s why I’m more concerned about this being a lithium-ion.
My guess at this point is that I should be ok because the current rating on my panel vs the razor battery is matched nearly perfectly. But I don’t know if the double to triple voltage would be a big problem. And if so, then whether or not a 12v charge controller would be needed.
Thanks in advance for all your help!
NOTE: I also have an older li-on razor that is 3v and 100ma. If I wanted to charge this one, separately from the one above, using the same solar panel, would I need a charge controller? Or am I going to be ok by simply attaching the panel to the charger for about 3-6 hrs at 14-18v and 150ma on the high end?
Thanks for the answers. As a follow-up and general question, let me ask you this.
When you have a solar panel that’s not matched voltage and current-wise to a device’s needs, how would you regulate both the current and voltage at the same time?
I know a voltage regulator can be used with resistors to maintain either a constant voltage or current.
But how would you regulate both voltage and current levels at the same time? For instance, reduce a 12v panel down to 6v. And at the same time, lower current from 100ma to 20ma?
Posted by admin on Saturday Jan 22, 2011
Filed under :12v Solar Panels
I want to heat a room that is 20" by 16 ". I have a 1500w ceramic heater and a 12v battery. How many solar panels would i need to heat the room?
and what size panels
Posted by admin on Thursday Jan 20, 2011
Filed under :Solar Charger
I’m going to china in a week and I would like to find a solar charger/portable battery that can charge from the sun or light in an airplane and from an outlet in the plane station. any help? I already checked out many ones online but cannot find one that can take a short time to recharge and provide over 6 hours of extra battery. It would be helpful if someone can find one that is compatible for the ipod touch or iphone. Thanks!
We already have an electric fence set up in our field but the battery keeps dying and it is a real pain. I want to use a solar panel to charge the 12V car battery that is the power source for our fence. I know nothing about solar panels besides the fact that they are direct current. What would I need to buy to charge the fence with solar panels? Could I just buy a solar panel and hook it up (however you do that) to our car battery that is connected to the fence charger or do I need to buy the whole set up for a solar powered electric fence? I don’t want to over charge the battery- what size solar panel would I need to safely charge the battery and do I need a charge controller (whatever that is)? I’ve tried researching online, but all I keep getting is adds for the complete solar powered electric fence set up. Any help would be appretiated thanks.
