The correct inverter is fitted

When we found the wrong inverter on the wall (a 6 kW EC 6.0 SP instead of the EC 8.0 SP we’d ordered and paid for), day-to-day running wasn’t the concern. Export isn’t switched on yet, the battery’s DC path was unchanged, and Predbat had already recalculated its plan around the 6.6 kW limit it reads from a sensor. The concern was timing. The swap needed to happen before export certification clears, because the extra 1.4 kW is what earns money during short, high-value export events.

Today the installer came back and fitted the correct unit, a Sigenergy EC 8.0 SP rated at 8 kW, with weeks to spare.

What changes

Not much on the software side, which is why we read limits from sensors rather than hard-coding them. Predbat will pick up the new 8 kW limit on its next restart and plan around it, with no config to rewrite. The discharge-rate scaling we’d set back to 1.0 for the 6.6 kW unit now simply reflects 8 kW.

The more awkward part is everything tied to the physical unit. The new inverter has a new serial number and a new network address, so the Modbus connection Home Assistant uses has to be set up again and the DHCP reservation pointed at the new device. None of it is difficult, but it has to be done when you replace the inverter on a working system.

Once it’s all back on the network we’ll check that the model sensor reads EC 8.0 SP and the plant power limit reads 8 kW, and that should be the end of it.