Plan Charging Action

The plan_charging action turns battery parameters into a complete cost-minimized charging schedule. Instead of manually computing energy, duration, and power, you describe the battery (capacity, current SoC, target SoC, max power) and the action returns a per-interval plan with SoC progression, cost totals, and segment grouping.

When to use this

If you already know the duration in minutes and just need the cheapest time window, use find_cheapest_hours or find_cheapest_block. Use plan_charging when you know your battery/EV parameters and want the integration to compute the duration, account for charging losses, and produce a SoC progression.

At a Glance

Situation	Example
Home battery: "Charge from 20% to 80%, efficiency 0.92"	current_soc_percent: 20, target_soc_percent: 80, battery_capacity_kwh: 10
EV with 3-phase charger: "Use 1/2/3 phases as needed"	charge_power_steps_w: [1380, 4140, 11000]
Battery with modulation: "30 W – 1200 W continuous"	min_charge_power_w: 30, max_charge_power_w: 1200
Deadline-aware: "At least 50% before next peak"	must_reach_soc_percent: 50, must_reach_by_event: next_peak_period
Arbitrage: "Only charge if later discharge is profitable"	expected_discharge_price: 0.28, reserve_for_discharge: true

Required Inputs

Field	Description
max_charge_power_w	Maximum charging power in watts (upper bound for every interval).
current_soc_percent or current_soc_kwh	Current battery state of charge.
target_soc_percent or target_soc_kwh	Desired battery state of charge.
battery_capacity_kwh	Required when you use percent values.

All other inputs (deadline, power steps, grid limit, economics, search range) are optional.

Choosing Between Fixed / Continuous / Stepped Power

Mode	Trigger	Behavior
Fixed	Only max_charge_power_w set	Every selected interval charges at full power. Last interval may over-shoot the target slightly (rounding up).
Continuous	Add min_charge_power_w	Planner can reduce the final partial interval down to the minimum power — no over-shoot.
Stepped	Add charge_power_steps_w: [a, b, c]	Planner picks the smallest allowed step that covers the remaining energy. Mutually exclusive with min_charge_power_w.

Deadlines

Combine a minimum SoC with a deadline:

• must_reach_soc_percent / must_reach_soc_kwh — the minimum you need by the deadline.
• Then pick one of:
  • must_reach_by — absolute datetime.
  • must_reach_by_event — one of midnight, next_peak_period, next_best_period_end.

The planner runs a two-pass schedule: first guarantee the minimum SoC before the deadline using the cheapest pre-deadline intervals, then fill the remaining target with the cheapest intervals from the full search range.

Economics (Arbitrage)

For "charge cheap now, discharge expensive later" use cases:

• discharging_efficiency — fraction still usable when discharged (default 1.0).
• expected_discharge_price — expected price per kWh at discharge time (in your configured display unit).
• reserve_for_discharge — when true, discards intervals that are unprofitable given the round-trip efficiency.
• max_cost_per_kwh — a hard ceiling; any interval above this price is discarded before scheduling.

The response's economics.break_even_price tells you the maximum charging price at which the round-trip still breaks even.

Examples

Home battery — charge from 20% to 80% overnight

Show YAML

service: tibber_prices.plan_charging
data:
  battery_capacity_kwh: 10
  current_soc_percent: 20
  target_soc_percent: 80
  charging_efficiency: 0.92
  max_charge_power_w: 2500
  search_scope: remaining_today
response_variable: plan

EV — 3-phase, at least 50% before next peak period

Show YAML

service: tibber_prices.plan_charging
data:
  battery_capacity_kwh: 60
  current_soc_percent: 30
  target_soc_percent: 80
  must_reach_soc_percent: 50
  must_reach_by_event: next_peak_period
  max_charge_power_w: 11000
  charge_power_steps_w: [1380, 4140, 11000]
  grid_import_limit_w: 16000
response_variable: plan

Battery arbitrage — only if profitable

Show YAML

service: tibber_prices.plan_charging
data:
  battery_capacity_kwh: 10
  current_soc_percent: 10
  target_soc_percent: 100
  charging_efficiency: 0.92
  discharging_efficiency: 0.92
  expected_discharge_price: 0.28   # ct/kWh value expected when discharging
  reserve_for_discharge: true
  max_charge_power_w: 3000
  search_scope: next_48h
response_variable: plan

Response Structure

The response contains the following top-level keys:

Key	Description
intervals_found	true when a schedule was produced.
battery	Normalized SoC / capacity / efficiency / achieved_soc_kwh (what you actually reach with the returned schedule).
charging	Mode, total duration, total energy, total cost, and the schedule block.
charging.schedule	segments[], intervals[], segment_count, seconds_until_start, seconds_until_end, and price statistics.
deadline	Present when a deadline was set — includes must_reach_by, must_reach_soc_kwh, achieved_soc_kwh, deadline_met.
economics	Present when any economic parameter was set — includes break_even_price, expected_net_savings, round_trip_efficiency.
price_comparison	Difference between the selected schedule and the most expensive equivalent window.
relaxation_applied / relaxation_steps	Whether the schedule was relaxed to fit available data.
reason	Stable reason code when no schedule was found (see below).

Per-Interval Fields

Each entry in charging.schedule.intervals[] includes:

• starts_at, ends_at, price, level, rating_level
• power_w — power assigned to this interval (watts)
• grid_energy_kwh — energy drawn from the grid
• stored_energy_kwh — energy actually stored after losses
• soc_after_kwh, soc_after_percent — cumulative SoC after this interval

Reason Codes

When no schedule is found, reason contains one of:

Code	Meaning
already_at_target	Current SoC is already at or above target — no charging needed.
no_data_in_range	The search range has no price data.
no_intervals_matching_level_filter	min_price_level / max_price_level filtered everything out.
no_intervals_after_economic_filter	max_cost_per_kwh or reserve_for_discharge filtered everything out.
energy_unreachable	The energy needed cannot be charged within the available intervals + power limits.
energy_unreachable_by_deadline	The minimum SoC cannot be reached before the deadline with the available intervals.
selection_above_distance_threshold	min_distance_from_avg is not satisfied by the cheapest selection.

Related

• find_cheapest_hours — when you already know the duration in minutes.
• find_cheapest_block — for appliances that must run uninterrupted.
• Scheduling Actions — shared parameters (search range, price filters, relaxation).