MIN_EFFICIENT_POWER

[055Richard]

Home Assistant Astrameter add-on with two Marstek batteries (800W load and 2500W unload per battery). What is the best value for MIN_EFFICIENT_POWER to achieve high RTE (for load and unload)? Currently set to 395.

[GENERAL]
DEVICE_TYPE = ct002
SKIP_POWERMETER_TEST = False
POLL_INTERVAL = 1
DEADBAND = 3

[CT002]
CT_MAC =
WIFI_RSSI = -50
UDP_PORT = 12345
DEDUPE_TIME_WINDOW = 0.9
FAIR_DISTRIBUTION = True
MIN_EFFICIENT_POWER = 395
EFFICIENCY_ROTATION_INTERVAL = 1800
EFFICIENCY_FADE_ALPHA = 0.3
BALANCE_DEADBAND = 30
BALANCE_GAIN = 0.2
EFFICIENCY_SATURATION_THRESHOLD = 0.65
SATURATION_ALPHA = 0.07
MAX_TARGET_STEP = 0
PACE_BASE_STEP = 0
PACE_MAX_STEP = 0

[055Richard]

Any options?

[tomquist]

Go for about 300–330. Once only one battery is running, the second doesn't join until demand reaches 2.4 × MIN_EFFICIENT_POWER, so at 395 a single battery has to cover up to about 950 W. That's fine when discharging, but when charging it sits at its 800 W limit and exports the rest. In a simulation of your setup that was about 50 W exported at 850 W surplus. Staying below 800 / 2.4 ≈ 333 avoids that, and each battery still runs at 300 W or more whenever both are active.

[055Richard]

Thanks.