A watchdog for impossible readings
Every battery reading is compared with the previous one. A jump from 0% to 50% in ten seconds is a sensor glitch, not physics, so it is logged quietly and summarised once a day instead of triggering anything.
My setup
The advice comes from a home that actually runs on it.
Before offering guidance to anyone else, I automated my own family home in Australia: rooftop solar, a 48 kWh home battery, an electric car, eight air-conditioning zones, two heat-pump hot water units and a handful of connected appliances. These are real screenshots and real automations from that home. Private details are deliberately left out.
- Automations in daily use
- 80+
- Areas mapped
- 16
- Entities organised
- 1,200+
- Climate zones
- 8
Rounded figures from my own Home Assistant system, September 2026.
Energy · the free-power window
The heavy lifting happens between 11 and 2.
Our electricity plan has a free three-hour window in the middle of the day, so the house moves its biggest loads into it automatically:
- Both heat-pump hot water units switch to performance mode at 11:00 and back at 14:00
- The dishwasher and washing machine start at 11:02, but only if they are loaded, the door is closed and nothing is already running
- The home battery and the car top up from the grid while it costs nothing
Why it works: each machine checks that it is actually ready before starting, and a simple “dishwasher loaded” toggle keeps a person in charge.
Energy · solar-balanced EV charging
The car charges from spare sunshine, and stops itself if it shouldn’t.
Outside the free window, charging current steps up and down to follow measured solar surplus. Three safety automations sit behind it:
- Real grid import for 30 seconds outside the free window stops charging at once
- Charging stops if the home battery falls below a floor I set
- If I turn on any charging mode while the car isn’t plugged in, my phone tells me
Lesson learned: the plug-in check used the car maker’s cloud service, which went stale during an outage. It now reads the charger’s own local sensor instead.
Small automations, big difference
The details that make it trustworthy.
None of these are flashy. They are the reason the flashy ones can be left running.
Scheduled switches are checked, not assumed
Fifteen seconds after a scheduled light or switch command, the system checks it actually happened. If a cloud service dropped it, it retries once, then alerts me if the retry fails too.
Restart recovery
If Home Assistant restarts in the middle of a battery charge or discharge window, recovery automations put the battery back into the right mode instead of leaving it in limbo.
A kitchen light that means “we’re exporting”
When the house exports more than 800 W of solar for half a minute, a light on the kitchen island turns on. It is a good moment to run something, and nobody needs to open an app to know.
A laundry fan that reacts to the air
The exhaust fan runs when humidity passes 60% or temperature passes 28 °C, and stops when both return to normal. A 90-minute cap covers a stuck sensor.
The garage looks after itself
The door opens for our cars on arrival and closes on departure, the light follows it, and a midnight check turns the light off if anything was missed. The door’s own remotes and safety sensors stay in charge.
Comfort and hot water
Everyday controls, one place.
Wall controllers and manufacturer apps still work. Home Assistant simply puts them side by side.
Architecture
One small server, clear boundaries.
Home Assistant runs in a container on a low-power home server, alongside a few other self-hosted services. Nothing on the internet talks to it directly.
Lessons learned
What I would do differently from day one.
- Name things before there are hundreds of them. A consistent room-and-purpose naming scheme saves hours later.
- Put settings in helpers, not inside automations. Changing a battery floor or charge window should never mean editing logic.
- Plan for restarts and dropouts. Every important routine needs a defined behaviour when a device or cloud service disappears.
- Prefer local sensors for decisions. Cloud integrations are fine for convenience, but a safety check should not depend on someone else’s server.
- Don’t trust a reading just because it arrived. Sanity-check values that drive money or safety decisions.
- Test the backup by restoring it. A backup that has never been restored is only a hope.
Your home is different
Borrow the lessons, not the whole setup.
Most households need five good automations, not eighty. Guidance helps you find the ones worth doing first.
Ask for guidance