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Topic: Measuring current from solar panel (Read 2092 times) previous topic - next topic

Hello frnds,
I am using arduino uno and i want to measure the current from the solar panel for my project , i don know what to interface to read the current, and i am newbie to arduino.

Please suggest some ideas ,

The current rating is from 0-5 A DC

afremont

Put a small value, precision shunt resistor in series with the cell and measure the voltage drop across it.
Experience, it's what you get when you were expecting something else.

strykeroz

Hi,

I've used a few of the hall effect current sensors from Pololu for this type of thing also.  In a project on a boat I measured solar and generator input as well as total battery discharge using 3 of these modules.  I also use them in my benchtop power supply.  This +/- 5A one based on Allegro ACS714 will give you the best resolution for the range you're measuring.

Cheers ! Geoff
"There is no problem so bad you can't make it worse"
- retired astronaut Chris Hadfield

Thank you Afremont and Strykeroz,

To strykeroz : can u also tel me how to design a dc-dc converter , and tell about your solar project , i have to design a solar charge controller,, it will be very useful for me ,


strykeroz

#4
Feb 24, 2013, 10:01 pm Last Edit: Feb 25, 2013, 07:13 am by strykeroz Reason: 1
Hi

Unfortunately neither of those projects will be too useful to you I think. The bench supply uses an ATX PSU with power broken out to 3v3, 5, 12 and variable posts on the enclosure.  A 20x4 character display outputs the current drawn from each... Plus temperature and a clock since it was already over the top.

The power hub on the boat is really a fuse box and power distribution board with a screen. The solar and outboard power are routed through it before the battery and all battery output goes through it also. This gives a simple indication of total charge or discharge of the battery since reset, instantaneous and cumulative moving average for those statistics... And cabin temperature, because I had extra pins ;)

Geoff
"There is no problem so bad you can't make it worse"
- retired astronaut Chris Hadfield

Chagrin

Atmel has an application note on battery charging. Starting in section 3.3 they start explaining the voltage and current measuring.

With respect to solar panels Tim Nolan's MPPT design is a must read.

Thanks Chagrin

Those links were so useful :)


Put a small value, precision shunt resistor in series with the cell and measure the voltage drop across it.

In solar battery charging systems every bit of energy is precious. A current shunt is just throwing away energy. Granted that it is a small amount but, if it can be avoided it should be. The use of a Hall sensor would be my first choice. Search ebay and you will find Hall sensors ranging from 5A to 30A .

afremont



Put a small value, precision shunt resistor in series with the cell and measure the voltage drop across it.

In solar battery charging systems every bit of energy is precious. A current shunt is just throwing away energy. Granted that it is a small amount but, if it can be avoided it should be. The use of a Hall sensor would be my first choice. Search ebay and you will find Hall sensors ranging from 5A to 30A .


True, but the first couple of Hall sensors that I checked out used 50mW while operating so you'd have to be careful.
Experience, it's what you get when you were expecting something else.

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