I’m running an off-grid system for our house with the following setup:
MultiPlus II 48/5000/70-50 (firmware v556)
3x Pylontech US5000
MPPT 250/100 | 12 panels
Cerbo GX (latest firmware)
Generator: Genergy Creta-SOL
Everything works fine — solar charging, inverter performance, and automatic generator control. I use a digital input on the Cerbo GX to start and stop the generator automatically. It also triggers when battery SOC drops below a set percentage (e.g. 25%) and stops charging once it reaches the configured level
However, I’ve noticed one strange issue:
The generator “Acc. Runtime” always stays at 2 seconds.
The generator itself runs perfectly. I can:
See runtime hours directly on the generator screen.
See in VRM when the generator is running, how much power it’s producing, etc.
But the accumulated runtime on the Cerbo GX never updates — it’s stuck at “2s” no matter how long the generator runs.
Has anyone encountered this before? Could this be related to how the digital input is configured (manual vs auto mode), or do I need to map the runtime via a Modbus or relay input instead?
A Digital Input cannot be used to start and stop a genset, therefore the relay is used.
By default, the runtime gets counted as long as the relay is closed.
However, you can configure a digital input to “Generator” and thereby use it to count runtime more accurately. If configured, the runtime only gets counted when the digital input is “closed”. This is usually connected to a digital output of your genset controller that reports if the genset is running or not.
I guess you have configured the digital input, but as it is always open, no runtime gets counted.
You’re absolutely right. It’s working now. I had set the digital input to genset even though there is no digital input at all, only the relay as you pointed out.
