I have a BlueSolar MPPT 75/15 charging two 140ah batteries in parallel (12vdc). This is done through a SmartShunt. On the batteries themselves I have a battery charger which is keeping things running while the weather is crappy and the days short. I have a larger solar panel in the garage which should help negate the need for the charger but it certainly isn’t helping where it’s sitting in the garage. Monitoring everything I have Venus OS running on an old Raspberry Pi.
The setup doesn’t run much but the pi and a couple of Ubiquiti antennas (powered by a 12v POE injector) in a remote area I can’t easily get power to (I mean, aside from the 5 or 6 extension cords stuck together running a 2a charger… )
The setup, minus the shunt, has been working for a couple of years now.
I added the shunt a few months ago, really only got it working consistently a couple of weeks ago (usb cable woes), but it’s been consistent for a few weeks - until 3 days ago (apparently).
The Problem:
My shunt (device 289) is showing some crazy high readings for voltage for some reason:
As you can see it’s showing in excess of 250V all of a sudden and there are no high voltage warnings in place.
Note I had everything disconnected earlier today making sure all my connections were snug and testing a few things with a voltmeter, nothing seemed odd or out of range)
The System is showing odd usage and voltage data also (I assume it’s calculated based of info from the Shunt?)
I just updated the Venus OS again and the Smart Shunt had some kind of bluetooth interface update I did while at the setup. Again I went over everything and checked for bad/loose wires, everything seems to be fine.
As you have checked all the connections and measured with a meter, only three things I can think of…
1 - Interference, between the Shunt and old Raspberry Pi (are you running VE.Smart Networking?)
2 - Bad cable (as you had usb cable woes) try another cable.
3 - Shunt gone faulty.
1 - No I am not using VE.Smart Networking
2 - While I can’t exclude this entirely I’d expect data to be all over the place or not work at all if the cable was bad.
3 - This is what I’m thinking but find surprising that it’s sending ever increasing voltage data alone.
I have replacing the usb cable on my radar and will give it a try when I can find the time. I did spend a bunch of time searching for my symptoms hoping to find a definitive answer but I can’t even find reference to someone else seeing the same thing happening.
Ok to eliminate the shunt what I would do is, take the shunt out of the system, connect it to a separate 12v source (Battery>Shunt>current) with a low current draw on it and monitor for a few days. (with Victron Connect on your Phone/PC with Bluetooth)
If all ok then more detailed investigation of the rest of the system is required, a process of elimination until you find the problem, i know it can be time consuming but always worth it.
Wellllll that was interesting. Turns out that it is indeed the cable that was causing the weird voltage reading. I was monitoring the data on the shunt via Bluetooth on my phone and unhooked the serial cable and the voltage dropped to an expected value. Plug it back in and it instantly went up again…
The voltage on my USB to Serial adaptor was set at 5vdc but I removed the jumper entirely and things seem to be working nicely, for the moment.
Sure, monitor it for a few days and when your confidante it all ok please come back here and let us know and mark it as solved that way if someone else get this issue it can easily be found, as they say every day is a school day.
