Pre-Peak Charge
Pre-Peak Charge is the smart upgrade to “always charge before peak.” It looks at your typical solar generation, today’s actual cloud cover, and your current battery level — and only pulls from the grid when solar genuinely won’t get you to your target by peak start.
Why it exists
Section titled “Why it exists”Tesla’s Time-of-Use mode is supposed to manage this, but most owners end up tweaking their rate plan trying to coerce the right behavior. Grid Getter already has the data — minute-by-minute battery telemetry, hourly solar/load history, weather forecasts — so we can make a real prediction instead of relying on rules of thumb.
What it does
Section titled “What it does”- Predicts your remaining solar from now until peak start. Uses your own site’s typical hourly solar profile, scaled by today’s observed clearness (today’s solar so far compared to typical), and optionally adjusted for forecast cloud cover.
- Estimates household load for the same window from your own history.
- Computes the deficit between your target battery % and what solar will deliver.
- Re-decides every 30 minutes — wait, start grid charging, stop, or done — and on every telemetry tick once you are within two hours of peak, so a late change in the forecast can’t slip through a gap.
- Hard deadline. If the deficit can’t be closed in the time left before peak (5 kW per Powerwall), grid charging starts immediately regardless of what the forecast says.
How predictions improve
Section titled “How predictions improve”The first two weeks after install, predictions blend a conservative cold-start baseline with your personal history. Once you have ~14 days of telemetry, the model uses your own site’s data exclusively. The weather forecast toggle is optional — with it off, the model still works using your historical curves and today’s observed clearness.
How it’s different from Battery Threshold
Section titled “How it’s different from Battery Threshold”Battery Threshold is reactive: drop below X%, charge to Y%. Pre-Peak Charge is predictive: only charge if solar isn’t going to get you there. On a sunny day with a half-empty battery, Pre-Peak Charge waits; Battery Threshold would have pulled from the grid unnecessarily.
Where to find it
Section titled “Where to find it”Pre-Peak Charge lives on the Background Rules page (Smart Controls → Background Rules), alongside Battery Threshold. That page is the home for automations Grid Getter runs on its own — the ones with no schedule for you to set.
You’ll also see it in a few places while you work:
- An announcement banner on the Automations page, until you set it up or dismiss it.
- A suggestion while you create a Peak Time or DemandGuard automation. That automation raises your reserve; Pre-Peak Charge makes sure there’s charge to raise it to, so the two are offered together. Added this way, it charges to the same reserve the paired automation holds.
- A lead-in on Today’s Automations, fused to the left edge of the peak window it serves and marked if needed — it only charges on the days the forecast falls short.
The charge prompt
Section titled “The charge prompt”Right now Pre-Peak Charge asks before it acts. On a day the forecast falls short, you get a notification about an hour before the top-up would need to start: Battery won’t be full before peak, with how far short you are. It carries two choices, Charge now and No thanks.
- iPhone: press and hold the notification to see the two buttons. A plain tap opens the app and offers the same two choices there, so either gesture works.
- Android: expand the notification to see the two buttons. A plain tap opens the app and offers the same two choices there.
- Web: the prompt also lands in the notification centre, where you can answer it until it expires.
The choices expire when your peak window starts. Charge now runs the top-up until peak begins and then puts your battery settings back; No thanks leaves today alone and the automation evaluates again tomorrow.
On the Live Dashboard
Section titled “On the Live Dashboard”When a top-up is planned or running, a card appears under Power Flow showing how today is tracking:
- Peak starts in — a live countdown to your peak window.
- On solar alone — what the battery is projected to reach by peak start with no grid help, against your target. This figure is deliberately labelled on solar alone: with the planned top-up, the battery does reach target at peak.
- Solar until peak and Home use until peak, with today’s solar shown as a deviation from a typical day at your site.
- Gap to cover — the shortfall the grid would have to make up.
- Charge window — when the top-up starts and finishes. It always finishes before peak begins. A planned window also shows the expected charge rate; once a top-up is actually running, the window shows real start and finish times.
Skip today suppresses just today’s top-up. The automation stays on and evaluates again tomorrow. Changed your mind? The same button becomes Undo skip — today’s top-up goes back on the table. Skipping while a top-up is already running ends it and puts your battery settings back, within a few minutes.
If clouds clear before the charge window opens, the top-up shrinks or is cancelled on its own — you don’t have to do anything.
Settings
Section titled “Settings”| Setting | Default | Notes |
|---|---|---|
| Target battery % | 100% | Slider, 50–100% in 5% steps — how full you want the battery at peak start. When Pre-Peak Charge is added alongside a Peak Time or DemandGuard automation, it starts at that automation’s peak reserve instead. |
| Use local weather forecast | On | Adjusts the solar prediction for today’s forecast cloud cover; with it off, the model relies on your historical curves and today’s observed clearness |
Pre-Peak Charge runs automatically before your peak window — its schedule comes from your rate plan, not a separate days/months picker. There’s nothing to configure beyond the two settings above.