Sunny Buddy: SET voltage cannot be adjusted below 7V

Components & Accessories Power
1

Hi,

I have been working on a simple Solar Powered Arduino project with Sunny Buddy, and have tried several things in order to get it work. The truth is, I am not an expert in the electronics field and I have learnt a bit during this voyage.

However - now my project has step-up module, second battery and second PV panel - and I still cannot get it work.

When is all properly connected, I cannot get more than 1.9V on the load connectors and the step-up module needs at lease 2V in order to work. (It is sunny and I get around 18V from PV panel)

What I got now connected is:

  • - Battery - 800mAh/3,7V (JA 603048P)
  • - PV - 5W, Umax=17.9V, Imax=0.28A
    • When I measure the SET pad (against GND) with no load and no battery connected, I cannot adjust the potentiometer down to 3V. I would not go lower than 7.2V somehow.

    I would appreciate if someone could shed some light into this situation for me.

    Thanks a lot in advance!

    Peter

    2

    Hi Peter,

    I’m not sure what would be causing that behavior with the Sunny Buddy. When you adjust the potentiometer, does the voltage measured between SET and GND change at all or is it stuck at 7.2V? Also, has this been a problem as long as you’ve been using the board or only when you added a second solar cell and battery? Have you modified any of the jumpers on the board? Finally, to get a better idea of your circuit, can you take a few photos of your Sunny Buddy and the circuit you have it in and/or a schematic of your circuit and attach it to your reply?

    3

    Hi TS-Mark,

    the (SET-GND)) voltage, was gradually changing from around 12V down to 7.2V as I was adjusting the potentiometer.

    No jumpers were modified, I have been using the board as is.

    This is a photo of my board with all of the peripheries.

    SunnyBuddy.jpg
    SunnyBuddy.jpg2016×1512 944 KB

    Any idea?

    Thanks!

    Peter

    4

    Hi again Peter,

    Thanks for taking those photos and providing the extra information about your setup. A quick suggestion before we call the board defective is to adjust that SET potentiometer with no battery or load attached. Give that a try (assuming you have not done so already) and let me know if that helps.

    5

    Hi Mark,

    I have always had no battery and no load connected, while trying to get to 3V with potentiometer. :frowning:

    So the board might have been defective the whole time? Mmmmm…

    Thanks anyway!

    Peter

    6

    I figured as much but from your photo I was not sure if you were trying to adjust it with a load/battery attached. If you purchased the Sunny Buddy directly from SparkFun, please fill out the form on [this page with a brief description of the problem and a link to this post and we’ll follow up with further instructions on how to proceed.](Return Policy - SparkFun Electronics)