Most Grid Getter setups stop at one DemandGuard automation and a peak window. That covers the expensive part of the day, and for a lot of people it's enough. But several settings inside the automation types don't get much attention, and a few of them quietly change what your battery does at the edges of the day. The edges are usually where the money leaks out.
Here are three rules worth building, and what each one is actually doing underneath.
Rule Idea 1 — A Reserve That Changes at the Peak Boundary
The default setup is a single backup reserve that never moves. It's a compromise: high enough that an outage doesn't catch you empty, low enough that there's something left to shave with. For most of the day it's wrong in both directions.
A Peak Time automation lets the reserve mean different things inside and outside the window. You set the percentage that applies when the window opens, then decide what happens when it closes. "Restore previous" puts the reserve back to whatever it was before the automation touched it, which matters more than it sounds like it should, because you or another rule may have moved it earlier in the day. The alternative is to name an explicit end value.
That second choice does more than the form suggests. Setting a start reserve and choosing restore-previous is exactly what switches on Demand Floor behavior: the start percentage becomes a floor DemandGuard won't dip below mid-window, and your original reserve comes back when the window closes. Pick an explicit end value instead and you've opted out of floor semantics entirely, even though that start percentage is still sitting right there in the form looking active. Two settings that appear independent are not.
Window length should drive the number you pick. SRP's E-27 runs 2pm-8pm on summer weekdays, a six-hour stretch. APS's 4pm-7pm plans give you three. SCE's TOU-D-PRIME peaks 4pm-9pm daily, and demand charges are spreading through California residential rates besides. Shaving six hours off a single Powerwall is a genuinely different proposition from shaving three, and a floor that's comfortable on one plan will strand you on another.
One thing to know before you type any reserve percentage anywhere: Tesla's cloud API silently ignores values between 81 and 99, snapping them down to 80 while reporting back whatever you entered. Grid Getter clamps to 80 on your behalf rather than letting you save a number Tesla is going to quietly discard. It's one of several gaps between what the Tesla app shows you and what the battery actually did.
Rule Idea 2 — Refill Overnight Without Setting a New Peak
Peak shaving leaves your battery low. That's the job working correctly. The question is how it gets back up, and the default answer is whatever solar shows up tomorrow, which is fine in June and unreliable in December. If you've never compared your production curve against your consumption curve month by month, that gap is bigger than you'd guess.
A Battery Threshold rule watches your state of charge every minute and grid-charges back to a target when it falls below a floor you set. Say 30% as the trigger and 80% as the target. When charging finishes it returns to self-consumption at your minimum reserve, or you can name an explicit reserve for it to land on. There's also a hold option that keeps the battery pinned at the target until the window closes instead of letting it drift back down.
The scheduling is where this gets good. You can define your own active windows, or you can set the schedule to derive itself from everything else you've built, in which case the rule runs in whatever time is left over and your dashboard labels it "Outside Peak Time and DemandGuard windows." No window arithmetic, and nothing to redo when you shift a peak window in the fall. Battery Threshold also defers during active DemandGuard intervals, so the two aren't fighting over the same battery: DemandGuard owns the peak, Battery Threshold fills in around it.
The trigger has to sit below the target, which sounds obvious until you try to build a rule that charges to 40% when it drops below 40%. The form will stop you.
Rule Idea 3 — Storm Posture in One Scheduled Action
Most storm prep advice amounts to a checklist you're supposed to remember to run. A Custom Schedule automation collapses it into a single trigger time.
One automation, fired once a day, can flip Storm Watch on, set your battery reserve, override grid charging to enabled, and switch your operational mode between autonomous and self-consumption. Those are checkboxes, not an either/or, so the whole posture change happens at one moment rather than across four visits to the app. Set the months to your California fire season or your Arizona monsoon season and it stops firing the rest of the year without you disabling anything.
Worth understanding what Grid Getter does and doesn't do with weather here, because it's easy to assume more. There's no trigger that watches for a red flag warning and raises your reserve on its own. What exists is protective: Weather Guard, on by default, stops your Demand Floor from being lowered while Storm Watch is active or severe weather is forecast for your area, and DemandGuard respects Storm Watch rather than working against it. So the automation keeps peak shaving from eating the reserve you're counting on. Deciding to raise that reserve ahead of a storm is still your call, and the Custom Schedule rule is how you make it stick.
Pair it with a second scheduled rule that puts everything back afterward. A posture you can't easily undo is one you'll leave running through November, giving up savings for a risk that passed weeks ago.
Building Your Own Rules
These are starting points, not a checklist. Once you start thinking about your energy use as a set of conditions rather than a fixed schedule, other rules start suggesting themselves.
Maybe it's a weekday-only charging rule, since weekend usage patterns don't justify the same demand-charge defense. Maybe it's a window built around when your EV actually charges, which is the single biggest load most Powerwall homes control. Maybe it's separate summer and winter versions of the same automation, using the months selector rather than editing one rule twice a year.
Event-day plans are worth a look before you build anything clever, though check what you're actually on first. Critical Peak Pricing at both SCE and SDG&E is a business rate rider, not something a standard residential TOU-D customer gets, so a "skip charging on CPP days" rule solves a problem most homeowners don't have. SDG&E does run residential event-day plans where you're asked to cut usage during a called window, and SCE's residential Power Saver Rewards paid bill credits for the same behavior, though that program isn't continuing past 2026. If you're on a plan with called events, a rule that raises your reserve ahead of the window earns its keep. If you're not, skip it.
The rate structures on E-27, the APS 4pm-7pm demand plans, TOU-D-PRIME, and the SDG&E EV plans all reward different behavior. A rule that's perfect for your neighbor on a different plan might be actively costing you money on yours. Look at your own bill's rate schedule before copying someone else's automation, and if the difference between an energy charge and a demand charge isn't clear yet, start there — the savings calculator will tell you what your plan is worth defending.
Set Rules That Match How You Live
A Powerwall without custom rules just reacts. It fills up and discharges on whatever schedule it defaults to, nothing more. Custom rules are how you tell it what actually matters to you; DemandGuard and your automations handle the execution from there.
If you haven't built one yet, start by opening your Grid Getter dashboard and checking your current backup reserve. If it's still at the factory default, that's usually the first thing worth changing. Then pick one rule from this list and set it up this week. The free plan covers live monitoring and a single custom automation, which is enough to try Rule 3; Peak Time and Battery Threshold sit on the paid tiers.
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