For Tesla drivers on Octopus Agile
Charge your Tesla for pennies. Automatically.
Octopus Agile reprices electricity 48 times a day. Ember watches every price, picks the cheapest window, and charges your car in it. You plug in. That is the whole job.
Free to download · iPhone · No card required
The problem
Electricity was nearly free about 370 times last year. Were you plugged in?
When Britain generates more power than it needs, especially from renewables like wind and solar, supply outstrips demand and Agile prices crash, sometimes below zero. The catch is that these cheap windows move every single day, and nobody has time to chase them. Ember chases them for you, so your car charges when power is cheapest.
Live · today on Agile
This is today's market.
Every bar is a real half-hourly price. On the same day it can swing from a teatime peak to a cheap daytime floor, often a 16× difference. Ember reads all 48 prices the moment they publish and charges your car at the bottom.
Today's peak
37.0p
per kWh at 17:30. Every car plugged in then pays it. Most are.
Today's floor
-1.0p
per kWh at 03:00. Octopus paid drivers to take them.
Ember charges at the bottom, every day.
How it works
Built for people who'd rather not think about it.
-
01
Plug in
Get home, plug in, walk away. Ember only ever controls charging at your home charger.
-
02
Ember picks the window
When tomorrow's prices publish, around 4pm, Ember locks the cheapest stretch that fills your battery to your target.
-
03
Charged, with a receipt
The car stops at your target and you get a notification: what it cost, and exactly what you saved.
In the app
- Set-and-forget targetPick 80% once. Ember fills to it at the day's lowest cost.
- Your price capSet a maximum. Ember skips days that cost more, and says why.
- Max Range for tripsEmber targets 100% using the cheapest slots before you leave.
- Recovery windowsPlugged in late? Ember finds the next cheapest stretch.
- Holiday modePick your dates. No charging, no notifications, until you are back.
- Every session loggedCost, energy, and saving versus a flat rate.
The tariff
Why not Intelligent Octopus Go?
Smart EV tariffs give your car one fixed cheap window and price everything else at a flat rate near the cap. Agile refuses that trade. Your car charges at the day's floor, wherever it falls, sometimes below zero. And because most half-hours price below that flat rate, the whole house saves, not just the car, from the kettle to the heat pump. Ember handles the car automatically. The cheap half-hours are yours for everything else.
One fixed cheap slot, same time every day. A flat rate near the price cap for every other unit, all 24 hours.
Ember's cheapest window moves with the market, and it is often in daylight when the wind is up.
Charging the car
Intelligent Octopus Go~7.5p/kWh in a fixed window. Dependable, blind to the market.
Agile + EmberThe day's cheapest window, wherever it falls. On plunge days, below zero.
Everything else you run
Intelligent Octopus GoFlat rate near the price cap, all day, every day.
Agile + EmberThe live half-hourly rate. Most slots below that flat rate.
The 4 to 7pm peak
Intelligent Octopus GoThe same flat rate. Simpler for those three hours.
Agile + EmberEmber charges in the day's cheapest window, which steers clear of the peak. Skip any day you like.
The whole house saves, not just the car.
Intelligent Octopus Go and price-cap figures are typical rates; both vary by region and cap period.
Get EmberNo small print
The honest bit.
Some days the prices are ugly. Agile can spike, though it is capped at 100p/kWh. Ember always charges in the day's cheapest window, so it stays away from the priciest hours by design. And if a whole day looks bad, you skip it with one tap and Ember stands down.
Or set a price cap and stop watching. When tomorrow's cheapest window still averages above your limit, Ember stands down for the day and tells you what it would have cost. A battery floor overrides that, so the car still charges when it is genuinely low. Changed your mind? Charge the skipped day straight away.
Going away? Holiday mode pauses charging and every notification for the dates you pick, then picks up the day after you are back. End it whenever you like.
You stay in control. Ember just does the boring part.
Compatibility
Tesla today. Your EV very soon.
We're nearly there. Ember charges Teslas on Octopus Agile now, and support for these brands is coming very soon.
Want yours next? Download the app and we'll tell you the day it arrives.
Get EmberPricing
Free to watch. £3.99 to never think about it.
The market, in your pocket.
- Today's and tomorrow's cheapest window, every day
- Full Agile price charts for your region
- Live battery, range and charge status
- A push when tomorrow's prices land
Ember does the charging.
- Fully automatic charging at the day's cheapest prices
- Smart notifications: when to plug in, what you saved
- Recovery windows when you plug in late
- Max Range mode for trips
- Skip a day with one tap
- Price cap: Ember stands down on days that cost more than your limit
- Holiday mode: no charging, no notifications, while you are away
- Savings analytics, every session logged
One app, both plans. Download free, upgrade when you are ready.
Cheapest window Ember has automated, per kWh
Projected saving per driver, per yearProjected from each driver's actual saving versus their previous tariff rate, annualised from their charging history so far. An estimate, not a guarantee.
Plunge-price windows in the last 12 months
Prices Ember reads and ranks for you
Figures from Octopus Agile data and Ember session history. Savings are measured against each driver's own previous tariff rate. Individual results vary.
Get started
Plug in. That's the whole job.
iPhone. A Tesla. An Octopus Agile tariff. That is all Ember needs.
FAQ
Questions, answered.
Do I need to be on Octopus Agile already?
Yes. Ember works on top of the Octopus Agile tariff. If you are on a different tariff, switching to Agile is free.
Is my Tesla safe? What can Ember control?
Ember only ever starts and stops charging at your home charger. It never touches driving, locking, or anything else.
What if I plug in late, or forget?
Ember charges during the cheap window it has set for you. If you plug in after that window has passed, open the app and pick the next best window in a tap.
How much will I save?
Ember drivers have saved hundreds between them so far, with automated windows dropping below zero on plunge days. Your own saving depends on your driving, your previous tariff and the market: Ember measures it against your own baseline, so no two drivers' figures are alike. An estimate, not a guarantee.
Does Ember ever charge at expensive prices?
Ember always charges in the day's cheapest window. If the whole day looks expensive, skip it with one tap and Ember stands down. Premium drivers can set a price cap instead: when tomorrow's cheapest window still averages above your limit, Ember skips the day by itself and sends one message with the window and both prices. Set a battery floor and it still charges when the car is genuinely low, whatever the price. You can override a skipped day and charge immediately.
What happens while I am away?
Turn on holiday mode, a Premium feature, and pick your dates, up to 90 days. Ember schedules nothing, sends your car no commands and sends you no notifications, then starts again the day after you get back. You can end it at any time, even if your subscription lapses while you are away.
Which cars work with Ember?
Tesla today. Support for more of the most popular EV brands (BMW, Volkswagen, Audi, Hyundai, Kia, Polestar and more) is coming soon.
What does it cost, and can I cancel?
Free to watch the market. £3.99/month or £38.99/year to automate charging. Cancel anytime.
iPhone only?
For now, yes.