I’ve got an off grid system with 2x Quattro 48/10000/140-2x100 inverters, connected to a Cerbo GX and BYD Premium LV batteries. I’ve seen the AC metering just disappear on a few occasions over the past month, always whilst the generator is running (triggered by the Cerbo based on SOC).
When in this state, the Quattro doesn’t seem to be aware of any AC input, so does not charge - or discharge - the batteries. It seems to just connect the generator to the loads without any interruption and you can tell from the BMS that the Quattro isn’t charging the batteries in the meantime. On one occasion the generator stayed running for 3 days solid even though the batteries usually charge fully in 6-7 hours. The Cerbo can only see the PV supplying the loads and assumes load = output, and the DC system (the Cerbo and a 3rd party charge controller) slowly drains the battery.
It’s evidently not a full breakdown in comms between the Quattro and the Cerbo as in this situation (e.g. the Ve Bus cable is removed) the Quattro shuts down as it doesn’t get signal from the BMS. It’s also intermittent, in as much as after a while it seems to recover and the Quattro kicks back in and resumes happily charging the batteries like nothing has happened, but this can happen multiple times on and off before the batteries are charged. Once they are charged and the Cerbo stops the generator, the Quattro carries on Inverting like nothing happened. I can’t see anything in the Cerbo logs and when in this state, the lights on the master Quattro is just Mains On ie Passthrough. What on earth is going on?!
You can see in this screenshot that the generator appears to cuts in and out several times during the 24 hour period. Some VRM advanced graphs attached below as well. You can see the BMS isn’t stopping the charge, and the battery voltage spiking up and down as the Quattro decides to charge, or not charge. There seem to be interruptions in the flow of information from the Quattro during the unwanted Passthrough periods.
