The right inverter is on the wall

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, the worry wasn’t the day-to-day. Export isn’t even switched on yet, the battery’s DC path is unchanged, and Predbat had quietly recalculated the whole plan around the 6.6 kW limit it read from a sensor. The worry was the deadline. The swap had to happen before export certification clears, because that extra 1.4 kW is exactly what pays out during short, high-value export events.

Today the installer came back and fitted the correct unit. Sigenergy EC 8.0 SP, 8 kW, now on the wall. The race is won with weeks to spare.

What actually changes

Less than you’d think on the software side, which is the whole point of reading limits from sensors rather than hard-coding them. Predbat will re-read the new 8 kW ceiling on its next restart and plan against it automatically. No config to rewrite, no numbers to chase down. The discharge-rate scaling we’d dialled back to a true 6.6 kW just goes back to reflecting a genuine 8 kW.

The fiddly part is everything that’s tied to the physical unit. The new inverter has a new serial number and a new network address, so the Modbus connection that lets Home Assistant talk to it has to be re-established, and the DHCP reservation re-pointed. None of that’s hard. It’s just the price of swapping the brain of the system out from under a live install.

We’ll confirm the model sensor reads EC 8.0 SP and the plant power limit reads 8 kW once it’s all back on the network, and then this chapter is properly closed.