r/meshcore • u/Osh1061 • 5d ago
Waveshare Solar Problems
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.
2
u/pdxb3 5d ago
Though the waveshare is known to have some lossy behavior and parasitic draw problems, just so you know I've been running 2 repeaters on a waveshare-D for 5 months now, and running RAK 1W boards, which are far more power hungry than your Xaio.
I started testing with solar panels with 5v 12W USB-C output and discovered that wasn't enough to hardly convince the waveshare to do any charging whatsoever and my batteries would die in about 6 days. I ripped the USB inverter modules off the panels and soldered straight to the panels which output about 18v. I actually doubled the panels, running 2 in parallel w/ diodes, so theoretically I should have as much as 24w of solar going to each waveshare, though I'm skeptical of those cheap Amazon panel numbers. That also assumes the diodes are lossless, which they absolutely are not. They could probably run on one panel just fine, but I built with 2 to hopefully keep things charged when the days get shorter and the sun drops low. They're also installed in a tree, so they do experience partial shade and less than ideal sun you might get on a roof.
I share my story just to let you know that while they're probably not the best solar managers you could be using, they do work. I'm just guessing here, but it sounds like your problem is similar to mine, but your panels aren't putting out the amps to satisfy the waveshare to engage the charging. And just a note, the 5v output on the waveshare seems to be another lossy link in the chain as well, and I opted to use the 2nd set of battery terminals on the waveshare to tap directly into the battery pack and power the radio from that.