Low Voltage Solar Panel w/ Step-Up Converter(s)?

Thread Starter

Chris01

Joined Mar 18, 2016
3
Hi everyone,
I'm very new to electronics so bear with me here. I'm trying to make a small solar panel that I can charge a 12 volt deep cycle battery with. I would like to use solar cells that have an output voltage of about 0.5 volts and 6 amps, which I understand is pretty typical. Since I would like to make the panel with only 6 cells, after I hooked all of them up in series, I would have a panel with an output of about 3 volts and 6 amps. Since 3 volts is obviously way too low to hook up to a charge controller, I would need to first run it through a step-up or DC-DC boost converter. Plus, I don't need anywhere near that much current. The problem is, however, I haven't been able to find a step up converter that can both handle 6 amps and step around 3 volts up to 12 (Also, keep in mind that the panels won't constantly be producing 0.5 volts. It could be less). My question is, could I hook up two step up converters in parallel to the solar panel so the amperage would get cut in half (6 amps to 3 amps each) since I have found a converter that can withstand this much current, or would this result in an uneven distribution of electricity? I did a little research and I read that the resistances had to be the same on each line for the distribution to be the same, but it should be pretty similar since I'll be using the same converter, correct? Is there any other way around this or is there a custom boost converter I can make so that it will do what I need? If not, should I look at either using different solar cells or just more of them? Thanks, Chris
 

ronv

Joined Nov 12, 2008
3,770
Hi everyone,
I'm very new to electronics so bear with me here. I'm trying to make a small solar panel that I can charge a 12 volt deep cycle battery with. I would like to use solar cells that have an output voltage of about 0.5 volts and 6 amps, which I understand is pretty typical. Since I would like to make the panel with only 6 cells, after I hooked all of them up in series, I would have a panel with an output of about 3 volts and 6 amps. Since 3 volts is obviously way too low to hook up to a charge controller, I would need to first run it through a step-up or DC-DC boost converter. Plus, I don't need anywhere near that much current. The problem is, however, I haven't been able to find a step up converter that can both handle 6 amps and step around 3 volts up to 12 (Also, keep in mind that the panels won't constantly be producing 0.5 volts. It could be less). My question is, could I hook up two step up converters in parallel to the solar panel so the amperage would get cut in half (6 amps to 3 amps each) since I have found a converter that can withstand this much current, or would this result in an uneven distribution of electricity? I did a little research and I read that the resistances had to be the same on each line for the distribution to be the same, but it should be pretty similar since I'll be using the same converter, correct? Is there any other way around this or is there a custom boost converter I can make so that it will do what I need? If not, should I look at either using different solar cells or just more of them? Thanks, Chris
A single boost converter will work, but ones that run off of 3 volts are a little hard to find already built. Keep in mind by the time you boost the 3 volts to 12 volts you will probably get only about 1.2 amps. Is that enough?
 

Thread Starter

Chris01

Joined Mar 18, 2016
3
A single boost converter will work, but ones that run off of 3 volts are a little hard to find already built. Keep in mind by the time you boost the 3 volts to 12 volts you will probably get only about 1.2 amps. Is that enough?
Yes that should be fine. The problem is, I haven't been able to find a boost converter that is able to run off of 3 volts AND withstand 6 amps of current. I've only been able to find ones that either support low input voltage and low current or high input voltage and high current. Is there one that I could make that would meet these specs? Like I said, I'm not very good with electronics yet, so I would need a schematic to work with as apposed to designing it myself.
 

ronv

Joined Nov 12, 2008
3,770
Yes that should be fine. The problem is, I haven't been able to find a boost converter that is able to run off of 3 volts AND withstand 6 amps of current. I've only been able to find ones that either support low input voltage and low current or high input voltage and high current. Is there one that I could make that would meet these specs? Like I said, I'm not very good with electronics yet, so I would need a schematic to work with as apposed to designing it myself.
Hmm, yep. May have to build one. Is there some reason you cant use higher voltage panel?
Tomorrow is a golf day, but if someone else doesn't come along I'll give it a shot.
 

abjadi

Joined Mar 28, 2014
18
I think you can use LM2577 as boost converter; but the minimum input voltage should be 3.5 volts.
And don't forget the voltage of solar panel is deroped so u need a higher solar voltage.
upload_2016-3-19_8-29-34.png
 
Top