This is what I have improved on the control system recently. Deliberately in plain language: you should be able to see that work is happening — without reading code.
Blueprint to download
Current version
1.0
The ready-made automation for Home Assistant — works with any dynamic tariff and any battery.
NewFirst release: the automation decides on its own when to charge, discharge or pause — based on the current electricity price.
NewWorks with any hourly tariff and any battery: the automation makes the decision, your own battery does the switching.
ImprovedA neutral band between cheap and expensive stops the system from flipping back and forth right at the price threshold.
What I am working on
My own system has been running for over a year and keeps getting sharpened. This is the honest record — including the mistakes I made myself and then caught.
These entries are summarised automatically from my own change notes.
Version 2026.10.4October 25, 2026
ImprovedThe controller now better recognizes when charging is worthwhile. It calculates more accurately with losses during charging and discharging as well as battery wear.
ImprovedThe battery stays full longer in the morning when high electricity prices are expected later in the day. This avoids expensive recharging in the evening.
ImprovedThe system now uses a more accurate electricity meter for its decisions. If there are problems with the measurement, you automatically receive a notification.
FixedError messages are now replaced instead of stacking up. The controller also no longer charges unnecessarily when the battery is already full.
Version 2026.10.3October 18, 2026
FixedThe energy flow display now always shows current values. During the autumn time change there were briefly outdated numbers, this has been fixed.
NewThe battery now records at which electricity price it was charged. This way you can later see whether charging at different times of day is worthwhile.
ImprovedThe displays now check more accurately whether the readings are still current. This means outdated data is detected more quickly.
Version 2026.10.2October 11, 2026
ImprovedThe controller now queries the battery less frequently and sends fewer commands. This protects the device and avoids overload.
ImprovedThe battery now charges to 95% during the cheapest hours when electricity prices are low. The time window for this is between 10 am and 5 pm.
FixedThe battery charge display now remains stable even if the connection briefly drops. The last valid value is retained.
FixedSmall adjustments to charging power are now maintained for one minute. This prevents too frequent switching back and forth.
Version 2026.10.1October 4, 2026
NewThe second battery is now controlled. It charges during the cheapest hours and releases power during expensive periods.
ImprovedDaily reports now show grid consumption and both batteries clearly. Charging schedules are calculated more reliably and change less frequently.
FixedWith pulsing consumers like pumps, the control now operates more smoothly and avoids unwanted grid feed-in. Outdated meter readings are detected and ignored.
SafetyThe controller monitors itself more closely and restarts automatically if values stop updating. This prevents incorrect operation during connection problems.
Version 2026.09.3September 27, 2026
FixedThe system sometimes charged and discharged the battery unnecessarily at night. This no longer happens.
ImprovedZero feed-in now works more precisely and reacts faster to changes at the electricity meter.
FixedFixed situations where the system jumped back and forth between two states. The system now runs more stable.
Version 2026.09.2September 20, 2026
ImprovedThe battery now charges only when really necessary. This reduces unnecessary charging cycles.
FixedThe inverter limit during charging now works correctly and persists after a restart.
ImprovedAt cooler outdoor temperatures from 30 degrees onward, the inverter can now deliver more power. Previously the limit was active from 28 degrees.
Version 2026.09.1September 13, 2026
FixedThe repeated clicking sounds from the battery are fixed. An overzealous monitoring mechanism was checking too frequently and has been disabled.
ImprovedThe software now detects conflicts when multiple processes try to access the controller simultaneously. This prevents error messages.
Version 2026.08.5August 30, 2026
FixedMissing consumption data from recent months has been recalculated. The daily overview now shows correct values since May.
Version 2026.08.4August 23, 2026
ImprovedThe overview now clearly shows how much you save when charging and discharging the battery. You can see at a glance your average costs for recent days, weeks, and months.
FixedThe display now correctly distinguishes between normal charging and emergency charging when the battery needs to be charged for safety reasons.
Version 2026.08.3August 16, 2026
FixedThe battery no longer switches back and forth between discharging and pausing. This had caused unnecessary switching cycles.
FixedA timing issue when switching to rest mode has been fixed. In rare cases, the controller could get confused.
Version 2026.08.2August 9, 2026
ImprovedThe system now reliably detects unstable internet connections and no longer responds with errors to brief interruptions.
FixedEmergency charging now works reliably even after the system has been restarted or the connection was interrupted.
ImprovedThe calculation of favorable charging times has been made more robust and no longer stops when unexpected problems occur.
Version 2026.08.1August 2, 2026
ImprovedThe charging schedule now runs in a single pass without additional interruptions. Status messages now show the actual reason why charging was stopped.
FixedFalse zero values are no longer displayed when the electricity meter temporarily provides no data. The display remains empty until real measurements are available.
FixedThe monitoring system now checks the actual switching history before raising alarms. This prevents false alarms caused by delayed recordings.
SafetyAll safety checks now work with current data and no longer make decisions based on outdated information. Additionally, timestamps are now correctly stored with time zone information.
Version 2026.07.4July 26, 2026
SafetyIn hot weather the system now reduces charging power in every operating state — including at night in rest mode. Before, there was a gap in which the fuse in the garage was unprotected.
ImprovedSwitching commands to the battery are now checked for their effect and repeated once if nothing happened.
FixedThe message "battery is charging" occasionally appeared when nothing was charging at all. It now only shows up when power is really flowing.
FixedValue added tax was applied incorrectly in one price calculation — the displayed electricity prices are correct again.
Version 2026.07.3July 21, 2026
NewA 15-hour power cut went completely unnoticed. The system now reports an outage immediately and checks by itself afterwards whether everything is running again.
NewNew monitoring for the case where the battery is full but still does not discharge.
FixedThe price monitoring raised a false alarm because quarter-hour and hourly prices were being mixed up.
FixedThe display showed the planned instead of the actual charge level — it now shows the real value.
Version 2026.07.2July 14, 2026
SafetyAt high temperatures the battery charges more slowly. Reason: the fuse in the garage has less headroom when it is hot — it has already tripped once because of that.
FixedThe grid fee was hard-wired in many places and partly wrong — about 21 instead of 12.5 cents. There is now exactly one source for it, which checks itself. That also makes the charging-cost calculation correct again.
FixedNo more discharging in the morning when the battery is empty anyway.
Version 2026.07.1July 7, 2026
NewThe most expensive hours of the day are never left uncovered — not even when tomorrow would be cheaper.
ImprovedConsiderably fewer false alarms: several checks were reporting problems that were not real.
FixedA wrongly stored reference price distorted the weekly report.
No support promise and no update guarantee: this is my private system, documented in public. What is listed here happened — what comes next is decided by everyday life.