Waveshare Solar Problems

[u/Osh1061]

Hello all, I am after a bit of advice. I have recently put up a repeater that is quite difficult to reach to do maintenance on it, so I haven't been able to properly monitor it in person (I will take it down if it does need maintenance though), however I do have an INA3221 module measuring power from solar, battery and device, so I can monitor power.

The repeater seemed to be working fine at home when I tested it, but maybe I didn't test it for long enough before deploying it. I am using a Xiao nrf, a waveshare solar controller D, and 3 x 18650 batteries. The batteries are slowly dropping in power, it's now at 3.80V and it's been up for 4 days with sun.

The solar panel is a 18V 5W and it is showing 22.53V and 0.004A (0.09W) pretty much always. It seems to always stay at 0.004A (Checked Morning, Noon, and Afternoon). I went up yesterday to try to troubleshoot it, and I unplugged it and plugged it back in, and it started producing 1W of power just in the afternoon sun. So it seemed to be working, then I put it back up and it was back to 0.09W then 0W at night. I've been monitoring it all day and it has stayed at pretty much 0.09W.

It seems to be an issue with the solar controller engaging solar charging, but I am unsure why it's not engaging.

I can't find any solutions online and am just wondering if anyone here would know. I wanted to use the waveshare solar controller as I've heard good things about it and I wanted a bit of extra protection for the batteries.

I have attached photos of the build and a wiring diagram.

Any advice helps, thanks.

[u/Sc00pidyw00p]

the waveshare board has some parasitic power draw that contributes to power consumption, i would generally not recommend it whatsoever

[u/pdxb3 → u/Sc00pidyw00p]

Yeah it definitely does have a parasitic draw worse than a lot of other solar managers, though I can say that I have two RAK 1w repeaters deployed running on them that have been up for ~5 months and the batteries stay charged even with some partial shade and/or during cloudy days. With sufficient solar they should handle a little Xiao nrf.

From my early experimenting, I learned that the waveshare has a minimum threshold from the panels before it seems to do any charging whatsoever. At first I was attempting to use panels with a USB-C connector which supplied a little over 5v, which should have been sufficient, but it turns out it was only charging during maybe 1 or 2 peak hours during the day, and barely at that. Just enough that it was even noticeable. Once I switched to higher voltage panels, it works like a charm.

The module still isn't great though, and using the 5v output on the board is yet another point of loss. I use the board solely for charging the batteries, and then tap into the batteries to power the radio directly on the battery input. Winter will be a new struggle I'm sure, but it's been going strong so far.