Predictive charging¶
Predictive charging is an optional feature that charges batteries from the grid when the expected energy balance for today is negative.
Decision logic¶
If (Usable battery + Solar forecast) < Expected consumption:
Charge from grid the exact deficit
Else:
Do not charge (cost saving)
- Usable battery: energy currently stored above the configured min SOC.
- Solar forecast: estimated production for today (Solcast/Forecast.Solar sensor).
- Expected consumption: 7-day rolling average. See Daily consumption estimate.
Charge target¶
When charging is triggered, the integration does not charge all the way to max_soc from the grid. Instead it calculates a grid-only target SOC — enough to cover only what solar will not be able to provide during the day:
solar_surplus = max(0, solar_forecast − estimated_consumption)
grid_charge = max(0, gap_to_max − solar_surplus)
target_soc = current_soc + grid_charge / capacity × 100
gap_to_max is the kWh distance from the current SOC to max_soc. Solar output in excess of household demand charges the battery the rest of the way during the day.
Example: the battery needs 5 kWh to reach max_soc. Solar forecast is 13 kWh, expected consumption is 10 kWh — a surplus of 3 kWh available for the battery. The integration charges only 2 kWh from the grid; solar handles the remaining 3 kWh during the day.
Multi-battery systems¶
In systems with multiple batteries at different SOC levels the grid charge is distributed proportionally to each battery's individual gap to max_soc. A battery further from full receives a larger share; a battery already close to full relies mostly on solar for its remainder. This prevents overcharging any single unit from the grid and minimises total grid import.
Available modes¶
| Mode | Description |
|---|---|
| Time Slot | Charges during a fixed window (e.g. overnight off-peak tariff) |
| Dynamic Pricing | Automatically selects the cheapest hours of the day |
| Real-Time Price | Activates/deactivates charging based on the current price |
Notifications¶
The integration sends Home Assistant notifications:
- 1 hour before the slot starts: energy balance analysis and charging decision.
- When the slot starts: confirmation that charging has begun.
Use the Override Predictive Charging switch to cancel predictive charging at any time.
