Smart charging explained
Smart charging is not just a fancier timer. It is the bit that lets an EV charger, car app or energy supplier choose when the car charges, so more of the charging happens in a cheaper or cleaner window.
Quick answer
If you are on Octopus Go, smart charging can be as simple as setting your charger to run during the 00:30 to 05:30 cheap window. If you are on Intelligent Octopus Go, Octopus can schedule the charge for you once your compatible car or charger is linked in the Octopus app.
The important distinction is control. A timer follows the same hours every night. Intelligent smart charging can move charging into the cheapest suitable slots, including daytime slots, while still aiming for the charge level and departure time you set.
What smart charging actually means
A basic charger starts when power is available. A timed charger waits for the hours you choose. A smart charger or smart vehicle connection can talk to an app or supplier system, then start, stop or pause charging based on tariff windows, grid conditions, your target charge and when you need the car.
That matters because EV charging is one of the largest flexible loads in a home. Moving a 30kWh top-up away from the evening peak can make a much bigger difference than moving a kettle, phone charger or TV.
The three common setups
1. Manual scheduling
You set a time in the charger app or the car. On Octopus Go, that usually means telling the charger to run between 00:30 and 05:30 so the car uses the off-peak rate.
This is simple and often good enough. It works with more cars and chargers because Octopus does not need to control the device. The trade-off is that it will not respond to a one-off cheap daytime opportunity, and it depends on your timers being set correctly.
2. Charger-app optimisation
Some chargers let you enter a tariff and a target, then the charger’s own app chooses when to run. This can be useful on tariffs where prices change during the day, especially Agile.
For fixed-window tariffs such as Go, the extra saving over a well-set timer may be modest. The practical benefit is convenience: you are less likely to forget a schedule, charge outside the cheap period or leave the car short of range.
3. Intelligent Octopus Go integration
With Intelligent Octopus Go, you link a compatible charger or supported vehicle in the Octopus app. You set the charge target and the time you need the car. Octopus then creates a charging schedule.
The current public offer is built around six whole-home cheap hours every night from 23:30 to 05:30, plus smart charging at the Intelligent Octopus Go off-peak rate when Octopus schedules it. That can include slots outside the overnight window. During those scheduled smart slots, Octopus says the electricity used by the whole home is charged at the discounted rate too.
Whole-home cheap slots, in plain English
The phrase “whole-home” is easy to misread. It does not mean every hour of the day becomes cheap. It means that during qualifying off-peak periods, the rate applies to the electricity used by the home, not just the electricity flowing into the car.
On Intelligent Octopus Go, there are two separate ideas:
- Guaranteed overnight window: 23:30 to 05:30, when the whole home gets the off-peak rate every night.
- Scheduled smart-charging slots: extra or shifted charging slots chosen by Octopus. If they fall outside the overnight window, the whole home gets the discounted rate during those slots too.
You still need the car plugged in and the integration working for smart-charging slots. If you use a boost or override that is not part of the smart schedule, it may be charged at the normal day rate.
Charge Cap and the six-hour limit
Octopus’s 2026 Intelligent Octopus Go change is about how much discounted smart charging can be scheduled in a day. The public explanation says customers still get the six-hour whole-home overnight window, plus up to six hours of smart charging measured from midday to midday.
In practice, most daily top-ups fit comfortably inside that. A 7kW charger can add roughly 40kWh before losses across six hours, which is a lot of normal commuting range. The edge cases are larger batteries, two-EV households, very low starting charge or irregular high-mileage days.
Charge Cap is there to help control what happens when the car would need more than the discounted smart-charging allowance to hit the target. The safe habit is to plug in earlier, set a realistic target and check the schedule rather than assuming every requested hour will be discounted.
If the Charge Cap toggle is not there
Octopus says the Charge Cap control appears in the device settings when it is available for your account. If you cannot see it yet, do not assume your tariff is broken or that every long charge will be protected automatically. Check the Devices tab, keep Octopus app notifications switched on and use the schedule shown in the app as the billing clue.
If the app warns that the requested target may need more than the discounted allowance, lower the target, plug in earlier or accept that part of the charge may fall back to the standard rate. A manual Boost is useful when you need range quickly, but it should be treated as an override, not as proof that the extra energy will be billed like a scheduled smart slot.
Billing and app data are not the same thing
The smart-tariff terms make the billing dependency clear: Octopus needs compatible smart-meter half-hourly readings, and third-party app data cannot replace billing data if readings are missing. The Charge Cap note also says detailed Intelligent Octopus Go usage views now sit in the Octopus app rather than on monthly statements, usually around a day behind real time.
That means charger graphs, car-app sessions and Octopus app schedules are useful evidence, but the bill still depends on the meter data Octopus can use. A physical in-home display is not a reliable guide to this tariff’s dynamic charging calculations.
Keep screenshots of unusual schedules, Boost use and any notification that mentions the six-hour allowance. They are helpful if you need to ask Octopus why a session was split between the discounted and standard rate.
Smart charging source check, 25 May 2026
Use this page as a setup and evidence guide, not as a promise that every car, charger or app state will behave the same way. The current Octopus sources still point to three checks before relying on Intelligent Octopus Go:
- the car or charger must be eligible and linked in the Octopus app;
- the home needs a compatible smart meter with half-hourly readings;
- Boost, manual overrides and conflicting car or charger timers can change how a session is billed.
If your setup includes solar, a home battery or a third-party charger schedule, keep one app in charge of the EV session where possible. Otherwise the car, charger, battery and Octopus app can all try to optimise the same night in different ways.
Source links checked
How much can you save?
The numbers depend on your mileage, efficiency, region and how much charging you can shift. Here is a rough illustration for an EV using about 2,400kWh a year:
- Standard flat rate (23.7p–27.6p/kWh): around £568–£664/year
- Go overnight rate (9.5p/kWh): around £228/year
- Intelligent Octopus Go smart-charging rate (8.0p/kWh): around £192/year before any day-rate charging
The big saving normally comes from moving EV charging away from a standard flat rate. Intelligent scheduling can add convenience and can unlock extra cheap slots, but it is still worth checking the day rate, standing charge, compatibility and your actual charging pattern.
Use the EV calculator for a more realistic estimate.
Charger app vs Octopus app
Most home EV setups involve at least two apps. The charger app handles installation, WiFi, firmware, device health and detailed charging history. The Octopus app handles the tariff connection, Intelligent Octopus Go setup, target charge and departure time where your charger or vehicle is compatible.
Avoid letting two different schedules fight each other. If Octopus is controlling the charge, keep any charger or vehicle timer set up in the way Octopus recommends for that device. If you are using a simple Go timer instead, make sure the car and charger are both allowing charging during the same off-peak hours.
Getting started
- Check whether you want a simple fixed cheap window or full Intelligent Octopus Go scheduling.
- Confirm your smart meter, EV and charger eligibility before assuming Intelligent Octopus Go will work.
- If you use Go, set the charger or car to the off-peak window and test it on a normal night.
- If you use Intelligent Octopus Go, link the charger or vehicle in the Octopus app, set your target and check the first few schedules.
- Keep an eye on the bill after the first charges so you know which sessions were billed at the cheap rate.
Bottom line
Smart charging is worth understanding because it affects both cost and reliability. For many drivers, a well-set Octopus Go timer is enough. Intelligent Octopus Go becomes more useful when your car and charger are compatible, you can leave the car plugged in regularly and you want Octopus to move charging into cheaper scheduled slots for you.
If you are still choosing hardware, start with the compatible chargers guide before buying anything just for a tariff.