Knowing Your Solar Day Before You're Up

Solar decisions get made early — unfold the blanket or don't, move the vehicle or don't, go easy on the fridge tonight or don't. WattsUp sends one message before sunrise with what you need to make them.

What it sends you

• What kind of day it is — graded against what your latitude can produce this week, not against a perfect summer day somewhere else. A clear day in a Tasmanian or Montanan midwinter is a good day for midwinter, and it gets told that way rather than called poor.
• How many hours are worth having — not sunrise to sunset, but the window where the light is strong enough to charge properly. On a patchy winter day that can be two or three hours out of nine of daylight.
• When those hours fall.

The hours and the window are two readings of the same thing. The count is taken inside the window the message names, never across the whole day, so it can never come out longer than the window — and a good hour that falls outside it isn't in the number. That is deliberate: a briefing that named a window and then counted hours somewhere else would be quietly describing two different days.

A day with nothing in it says so — Grey and low sun — limited charging today. followed by Worth a look at the app when you're up. On a day with no charging hours at all the app drops the number rather than printing a zero; the window carries the message instead. Worth knowing at 6am, because the useful response is to ease off the big loads rather than to spend the afternoon checking connections.

When it arrives

An hour before sunrise, and never before 5am local — an hour ahead of a 3:40am midsummer sunrise in northern Norway is nobody's idea of useful.

Early because the decision has a deadline. By the time you've looked at the sky you've already set up or you haven't, and a 9am alert about the good morning light is a report, not a decision.

The first briefing is for tomorrow. Turn it on the night before you leave, not at the campsite. Each message is written and handed to your phone's own alarm clock ahead of time, and the app only ever queues mornings it has a real forecast for — a day it knows nothing about is skipped rather than invented.

Switching it on

It lives in Settings, under the heading WattsUp, on a row called Morning briefing — A heads-up on the day's solar — on-device, no tracking. It ships off; flicking the toggle is what starts it.

The toggle doesn't fire your phone's permission box straight away. It shows a card first — A heads-up each morning ☀️, with Turn it on and Not now — and only the deliberate tap asks the phone. That order matters on an iPhone, where the system asks once in the app's whole life: decline it there and it can never be asked again.

If notifications are already blocked, the card says so instead and offers Open Settings, and the row back in the app carries ⚠ Notifications are off in Settings — tap to re-enable. Your answer to the toggle is kept either way, so switching notifications back on at the phone level resumes the briefings the next time you open the app — you don't have to toggle it again.

The weather warning is the one to act on

It fires on sustained wind at 55 km/h, gusts at 70 km/h, or forecast hail, thunderstorm, cyclone, hurricane, tornado or blizzard. Those thresholds are about the point where a light panel on soft ground starts behaving like a sail, not about the panel's survival rating. For a storm the wording changes to name it and to say the quieter thing plainly — worth packing the panels away before it hits.

It arrives an hour before the dangerous weather starts, as a message of its own, under the same WattsUp name with a wind glyph rather than a sun. An hour is enough that packing up is a plan rather than a scramble.

If the dawn briefing already knows, the warning also rides on the end of it — Thunderstorms from ~2pm — worth planning an early pack-up. That only happens when the danger is at least three hours after the briefing goes out. Closer than that and the dawn message says nothing about it, because the hour-before alert is already on its way and would arrive first anyway. So the two are alternatives, not a pair: on an early-morning blow the standalone warning can land before the briefing does.

Two things it is not. It reads the forecast, not your campsite — it has no idea whether your panels are actually out, so it warns either way and leaves the judgement to you. And tapping it opens the app's main screen rather than a card: the live danger strip there is the up-to-date version, and the warning in your hand is a forecast that was written earlier.

What's behind the tap

Tapping the morning message opens a card headed WattsUp ☀️ and the time it was sent. Under that heading it is three blocks stacked, never one rewritten paragraph. The morning message sits at the top exactly as it went out — it is never quietly edited to look right. Underneath, the app adds what has changed since.

How the day is actually going

One sentence, and only when something has genuinely moved. If the sky has changed band it says Cloud cleared — better charging than expected. or More cloud about — slower charging than expected. If the charging hours have moved by two or more it says Better conditions than expected — a longer charging window today. or Worse conditions than expected — a shorter charging window today. Anything smaller is forecast noise, and the line stays away rather than manufacturing news.

It never quotes a figure. The morning claim and the live one sit next to each other so you can see when the forecast was wrong, instead of being handed a new story — and the numbers themselves are one more tap away on the main screen, which is the instrument. WattsUp is the messenger.

How tonight looks

One of three sentences: Tonight looks covered., Could be tight tonight depending on how the day goes. or Tonight looks short on solar alone. No percentage, no amp-hours.

This is a projection, not a reading. It is the same overnight walk the main screen does — your battery from where it is now, forward through tonight's draw, to two hours after tomorrow's sunrise, compared with the safe floor for your battery chemistry. Clear of that floor by a comfortable margin reads as covered; above it but inside the margin reads as tight; landing under it reads as short.

It is the only place WattsUp says anything about your battery rather than the sky, and that is why it lives on the card and never in the notification. A notification is written before dawn and then frozen, so it could never quote something that has since moved. The card is live, so it can.

The line needs a fair bit before it will appear — Pro, at least one panel saved, a battery type, your own current battery percentage entered, a real sunrise and sunset at your latitude that day, and enough recorded draw for the app to have a rate to walk forward. Miss any one of those and there is simply no tonight line. That is the app declining to guess, and it is the same gate the main screen's own overnight rows use, so the two can never disagree.

Your way out, when the day has settled

If tonight is short and you have a generator or a DC-DC ticked in your setup, the card adds the remedy: Worth running the genny for a bit this arvo to put some back in., A decent drive this arvo'll put a fair bit back in via your DC-DC., or A genny hour or a decent drive this arvo'll put some back in.

You will not see it at breakfast, and that is deliberate. It stays quiet until the day's charging is effectively over — until then a shortfall is a forecast a sunny afternoon might erase, and the app won't send you out to the generator over it.

It also stays quiet when you are comfortably clear, when your rig has neither a generator nor a DC-DC, and at latitudes and seasons where the sun never climbs high enough or never drops, because there is no honest deadline to point at. So on the morning tap the card usually stops at the verdict. Open the same message again late in the day and the way out is there if you need it.

It goes quiet when you do

Briefings run for two days after you last opened the app, or for the length of a trip you've started in the Pro trip planner, up to a fortnight.

The mechanism is the point. It doesn't watch your usage to decide whether you're still interested — opening the app schedules a short rolling window, and if you stop opening it the window runs out. Nothing is recorded about you, because nothing needs to be. A feature that tapers off when you stop camping is normally built on a usage profile sitting on someone's server; this one is built on an alarm that isn't renewed.

The queue only reaches as far as the forecast does. A fortnight-long trip does not get a fortnight of messages lined up the day you start it — the app writes a briefing only for mornings it actually has weather for, and quietly skips the rest rather than inventing a day it knows nothing about. Those later mornings fill in as the forecast catches up, which is the real reason to open the app once a day on a long trip.

There's no account, no tracking and no analytics of any kind. The sun and battery maths runs on your phone, and every briefing is written there too. The only time your location leaves it is the weather request, so the forecast is for where you are — and nothing is stored.

Out of range, and Bush Bash Mode

Because each message is written in advance and handed to your phone's own alarm clock, it arrives whether or not you have a bar of signal that morning. Nothing is fetched when it fires.

What needs signal is the rebuild. Open the app somewhere with no reception and the app has no fresh forecast to re-write the queue from, so it leaves what's already scheduled alone rather than wiping it — better an older message than none. Those briefings then fire from the forecast as it stood when they were written, and the card doesn't stamp how old that forecast was. It shows when the message was sent, not when the weather behind it was fetched.

Bush Bash Mode is the part worth knowing. While it is on — and it switches itself on whenever the phone is offline — the app deliberately stops fetching weather and works from the reading it saved. The main screen keeps answering from that saved reading.

WattsUp does not. With no fresh fetch there is nothing to rebuild the schedule from, so once the queued briefings have run, no new ones are written — and that holds even back in range, for as long as the mode is on. Switch Bush Bash off, open the app, and the schedule rebuilds from the next fetch.

Getting the most out of it

What it won't tell you

It's a forecast, and it behaves like one. The message is written before dawn and locked, so a day that turns out better or worse doesn't change it — which is why the correction lives on the card.

It doesn't tell you how old the forecast behind it is. The time on the card is when the message was sent, and out of range that message can have been written from weather fetched a while earlier. If a briefing looks out of step with the sky, open the app: the main screen is the live half.

It doesn't know your campsite. Trees, an awning, the ridge to the west: none of that is visible to a phone. It gives you the half you can't work out by looking — what the sky will do and when the light is worth catching — and you supply the other half with a glance upwards.

And it won't print a number it can't stand behind. With no position fix, or no forecast for that morning, no briefing is written at all rather than a vague one. With no battery percentage entered, no panel saved, or a setup it doesn't know yet, the overnight line simply doesn't appear. That's the app declining to guess, not a fault.

Wake up knowing what the day's got

The WattsUp morning briefing is free in Solar Spotter — no account, no tracking, and your data stays on your phone.

Zero data collection · Your data stays on your phone