I have a Cerbo GX and Phoenix 1200 inverter. My system is off grid, I monitor remotely with VRM.
Thing is, I get random (no pattern) low voltage alarms from the Phoenix 1200 every 2-10 days, sometimes none for 2-3 weeks, but then it'll happen again. It will be a low voltage alarm, showing 11.5V or something.
I go into the history of voltage and SOC using Cerbo GX paired with smart shunt, and I see nothing below 13.5V. Maybe 13.4 if there is a day of no sun. Anybody have any ideas?
Sup stranger?
What is actually reporting the alarm? The Phoenix itself? Is DVCC enabled with the smartshunt identified as the SCS, SVS and STS (if you have temp sensor)? If yes, then the shunt is feeding the Phoenix that voltage.
Cerbo/VRM will only catch readings based on its update frequency, which is no more often than 1 minute. Next time you're onsite, use bluetooth to connect to smartshunt with Victronconnect (not through VRM). Go to trends and select SoC and Voltage. Once you've done that, it will log data for 45 days at a much higher rate (every 1-2 seconds or so?).
Connecting to the shunt via VC and VRM will not enable or view any logged data except for the active session. If you connected to it through VC on a PC via VRM and kept the trends tab open, it should "log" for as long as the VC session is active. This might give you a clue before your next visit.
While you can only access that logged trend data through bluetooth, you will at least get a very accurate log of what's going on once you're back onsite.
I'm pretty confident you'll trace it to your BMS(es) - they are going dormant or doing something weird. Low drain situations can see BMSes go into low power mode where they report a notably lower voltage.
Lastly, if you have the stupid LiTime self-heating batteries that cut discharge briefly when charging is terminated, that's likely your issue. Stupidest batteries on the planet.
The phoenix is reporting the low voltage alarm.
I do not have DVCC enabled as my 'stupid self heating litime batteries' are not listed in the approved list of compatible batteries.
I logged into VRM, hit advanced, and opened up the System Battery Voltage & Current (I believe that's what you meant by VC) but the frequency, even if I pare it down to the last hour, is still about 5 minutes apart on the graph.
I wonder if I can pop these batteries open and run a different BMS. So frustrated with these.
VC=VictronConnect
DVCC can be used with lead acid. DVCC is required for BMS communications, but it has other non-BMS functions as well. Sharing voltage, temperature and current data from your shunt to all connected devices is one of them.
I used it with lead acid to limit my charge current to something safe for my batteries. This limited charging, but it still allowed the MPPT to output more than that current for loads if needed.
Recommend you enable DVCC and enable SCS, SVS and STS (if you have a temp sensor on your shunt). The benefit of this is to propagate the same data to all connected devices. The MPPT will charge based on the shunt voltage and charge current rather than it's own less accurate measurements.
In the GX console, you need to go into Settings > VRM and set logging frequency to 1 minute.
The logging I referenced in my initial response was for local bluetooth connection directly to the smart shunt ONLY. The goal is to setup your shunt to log data for 45 days so that when you're on-site, you get a very detailed record of what's happening in the VictronConnect Trends tab for the shunt.
Unfortunately, for remote options, VRM at 1m intervals is all you get.
I will also add, the Phoenix itself is flaky in terms of connection. Right now it shows as unknown, last seen 4 hours ago. I did some googling and I did find people with Phoenix units they had to return, newer units did not have the low voltage alarms. I'm wondering if this inverter is just bunk.
Plan this winter is to put external battery warming mats in the box, hooked up to the inverter. Should be able to turn the inverter on/off manually, or possibly put it on eco mode and use a programmable timer to turn the heaters on and off. This should preheat the batteries so I don't have any weird ass charging situations with these 'self heating' batteries.
If the Phoenix is measuring a weird voltage, DVCC with the shunt as SVS may fix it since the Phoenix will ignore its own voltage reading.
You have Dynamic Cut-off switched on? Its not workíng and produce errors.
