Solar Tracker

Discussion in 'The Projects Forum' started by sunwarrior1993, Nov 21, 2013.

  1. sunwarrior1993

    Thread Starter New Member

    Nov 20, 2012
    Good day, everyone.

    I'm finishing high school this year, I have to develop a project to finish my technical course (Electronics, Automation and Computer Science).

    My project is a Solar Tracker, with the help of my professors we'll decide if have the chance to insert the X and Y axis for the solar panels.

    Let me break it down:
    - 6 solar panels, each produces 1.5V, that gives a total of 9V.
    - A 9.6V Ni-Cd battery pack will be used to store power, for further experiments in robotics or even powering other devices.
    - The battery can be charged by building a Ni-Cd battery charger.

    The charger circuit that my professor shared with me has a LM317 Ajustable Voltage Regulator.

    However, I'm concerned about the voltage regulation because I won't need it, I suppose.
    And also about the energy production, can 9V charge a 9.6V battery in DC?

    Any help or guidance will be deeply appreciated.
    Thank you :).
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    The open circuit voltage from the panels (when in bright sun) needs to be about 1.5X to 2X the open-circuit voltage of the batteries you are trying to charge. Only other option is to connect the panel output to the input of a step-up Switch Mode Voltage Converter whose output is high enough to charge the batteries. NiCads are charged with a constant-current, but the voltage required will need to go as high as ~12V

    Read how to charge NiCads (and NiMh) here.
    sunwarrior1993 likes this.
  3. wayneh


    Sep 9, 2010
    I agree with Mike - you'll need a DC-DC converter to boost the voltage. You can find them cheaply all over e-bay. On the upside, this is more efficient than the LM317 voltage regulator.

    Without the boost, the only way you can charge the batteries is to use a switching arrangement whereby you charge the batteries in parallel but then switch them to serial to supply the load. Since your cells are in a pack, this may not be an option.
    sunwarrior1993 likes this.
  4. donpetru

    AAC Fanatic!

    Nov 14, 2008
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  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    I'm puzzled. Your project is a solar tracker, but the details given and your question are about battery charging ??
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Typically once one builds a solar tracker they attach it to a solar panel.

    One application of solar panels is to charge batteries.

  7. sunwarrior1993

    Thread Starter New Member

    Nov 20, 2012
    MikeML, wayneh and donpetru: Thank you for the information, I will definitely check out the link and the PDF file. :)

    Alec_T: Yes, my main issue was about the battery charging, but now I understand that I need a higher voltage than the input voltage produced by the solar panels, to charge the battery pack.

    I started to do some research about the Boost Converter.

    Again, I appreciate your help.

    Best regards.