Wattson intelligently charges your EV and home battery when electricity is cheapest — and stops when it's not. Hands-free, every day.
Works with Tesla · Hypervolt · GivEnergy · Solis · Sigen
Whether you have an EV, a home battery, or both — Wattson finds savings you'd never spot yourself.
Plug in and forget it. Wattson checks tonight's half-hourly prices and schedules your charge for the cheapest window — every time, automatically.
Shifting a 10kWh overnight charge from 35p peak to 7p overnight saves £2.80 per session — over £1,000/year for typical EV owners.
Typically £50–£120/monthCharge your home battery when electricity costs next to nothing overnight — then draw from it through the expensive evening peak instead of buying at high rates. Every unit charged at 5p and used at 35p saves you 30p.
A 10kWh battery charged overnight at 5p covers your evening peak load for free instead of paying 35p — saving £2.50+ per day without exporting a single unit.
Typically £40–£80/monthNot sure whether to switch to an Agile tariff? Wattson shows you — using your real energy data — exactly what each tariff would have cost you today.
We compare Octopus Agile, Intelligent Go, Cosy, Flux, and more against your current spending so you can switch with confidence.
Know before you switchThere are other optimisers out there. Here's what makes Wattson different.
Other optimisers control one device in isolation. Wattson coordinates your EV, battery, and charger together — so your battery never wastefully discharges while your EV is charging.
If tomorrow's solar forecast will top up your battery for free, Wattson won't waste money pulling from the grid overnight first. Smart enough to know when not to act.
Ask Wattson anything — "Why did you charge at 3am?", "What would I save on Octopus Go?", "How much solar did I generate this week?" — and get a plain-English answer.
Wattson isn't tied to one energy supplier. It works across Octopus, EDF, and more — and helps you decide if switching tariffs is worth it before you commit.
If tomorrow night's prices are significantly cheaper than tonight's, Wattson defers the extra charge rather than filling up now. It looks 24 hours ahead so you always charge at the best price across two days.
Connect your devices once and Wattson handles everything — every day, every session, every price window — with push notifications to keep you in the loop without the hassle.
From sign-up to savings in minutes.
Sign up free in under two minutes. No credit card, no commitment.
Link your Tesla, GivEnergy inverter, Hypervolt charger, or other compatible hardware using your existing credentials.
Tell Wattson your energy provider. It will automatically fetch today's half-hourly prices — and show you how other tariffs compare.
Wattson plans the optimal charge schedule every 30 minutes. You just plug in and go.
Unlike a fixed-rate tariff where you pay the same price all day, Agile tariffs update every 30 minutes based on wholesale energy costs. Prices are published the evening before — so Wattson knows exactly when to charge.
Connect your inverter or battery today. We'll analyse your real usage and show you exactly what you'd save before you commit to switching.
Example based on typical usage with a 5kW battery — Wattson shows you this with your actual numbers.
* Illustrative example. Wattson shows your personalised comparison on the dashboard using your own energy data.
Connect your device and enter your current tariff rate. Within a day or two, Wattson will show you: "You paid £X. On Agile with Wattson you'd have paid £Y."
Connect your inverter, battery or EV charger — no need to be on Agile yet
Enter your current unit rate so we can calculate your actual spending
Get a personalised savings estimate — with a full tariff comparison — on your dashboard
No commitment. No need to switch tariff to get started.
Wattson connects directly to your hardware — no additional hub or subscription required.
All Tesla vehicles via Tesla Fleet API
Hypervolt EV chargers
GivEnergy inverters & batteries
Via Solis Cloud or local Pi agent
Sigen home battery systems
New manufacturers added regularly
Agile tariffs reward households that can shift when they use electricity. The more you can shift, the more you save.
EVs are the biggest single electricity load in most homes. Shifting a 7kW overnight charge from peak (35p) to cheap (7p) saves £2+ per session — that's over £1,000/year for regular drivers.
Batteries can charge overnight at near-zero prices and discharge during the expensive evening peak. Wattson does this automatically, every day — with no need to set schedules yourself.
Solar + battery + Agile is the ultimate combination. Generate free energy during the day, and charge from the grid only when it's nearly free overnight — so the battery is always full when you need it.
Even without an EV or battery, running the dishwasher and washing machine overnight instead of at 6pm makes a noticeable difference to your bill.
Agile prices can spike during cold winter evenings — sometimes above 50p/kWh. If you use a lot of electricity at peak times without being able to shift it, you could pay more than a fixed tariff. Wattson can't control everything you use, so if your household draws heavily from the grid at peak, Agile may not suit you.
Connect your devices today and Wattson does the rest — every day, every charge, every price window.
Start saving for freeNo credit card · No commitment · Takes less than 5 minutes