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.
- Decides every ~15 minutes: wait, start grid charging, stop, or done.
- 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.
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 |
| 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.