Charge controller loading requirements for solar panel setup

Discussion in 'General Electronics Chat' started by Connor May, Jun 11, 2016.

  1. Connor May

    Thread Starter New Member

    Jun 11, 2016
    I want to power a micro controller and a vibration (piezo) sensor circuit (for waking up the micro controller) using solar power as an energy source. I understand that I need at least four things:

    1. Solar panel array
    2. Charge controller - 3 port setup, 1 for solar panel, 1 for battery, 1 for external load
    3. Battery
    4. Load center for distributing power to the two loads, the uC and a comparator circuit for the sensing element

    My question is, can you plug just any load into a charge controller, as long as it is below the maximum output power rating of the charge controller? Or does the load need to match the voltage of the battery (e.g. 12 V)? And if this is the case, what is the easiest way to convert the output to values within the operating voltages of my microcontroller (1.8-3.6V)?

    I have spent some time looking for an answer on the internet for this, but haven't come up with any concrete information to my question, but I hope that this post isn't too trivial. I appreciate any tips you guys can provide.
  2. crutschow


    Mar 14, 2008
    Why not just use a controller with one output to charge the battery and power everything from the battery as is typically done?
    You then use a linear voltage regulator (such as the common LM371) to regulate the voltage for the microcontroller.
    For higher currents (above a few tenths of an amp) and/or better efficiency you can use a switching buck regulator.
    Connor May likes this.
  3. Connor May

    Thread Starter New Member

    Jun 11, 2016
    Thanks for your help, I think that makes more sense, too. And it should be possible to run the battery in parallel, as in have multiple loads attached to the battery at once, both running a voltage regulator, correct? Will there be any issue with power supply for this? The system should be able to run 24/7.