Always-on loads inside the Battery
inverter control computers
battery management system (BMS)
grid synchronisation circuitry
relays/contactors
cooling electronics
communications (Wi-Fi / cloud)
safety monitoring
Typical internal consumption: 60โ150 W continuous
๐ Why Not Just Use the Battery?
This seems logical:
โI have a battery โ why import anything?โ
But inverter designers intentionally avoid this overnight.
If powered from battery instead:
Every night would cause:
tiny discharge โ recharge โ discharge โ recharge
Thousands of micro-cycles per year.
Lithium batteries dislike constant shallow cycling more than steady rest.
So Sigen prefers:
Grid powers inverter idle load
Battery sleeps
This improves long-term battery health.
โก Why It Happens Mostly Overnight
During the day:
solar already powers inverter electronics
battery already active
At night:
solar = 0
inverter decides grid is cheaper than battery wear
So you see a flat baseline import.