Will my EV be fully charged by morning if it only runs during cheap hours?

Yes — you set how many hours per day the charger runs. A typical overnight trickle charge (6–8 h at 2.5 kW) adds 14–18 kWh, which is enough for 70–90 km. Elewatt picks the cheapest hours within your chosen window, so by morning your car is charged and your bill is lower.

Is it safe to switch an EV charger on and off repeatedly?

Yes. The Shelly plug controls AC power to the charger, not the car's battery directly. Your EV's onboard charger (and most wallboxes) are designed to handle frequent starts and stops — they pause and resume gracefully. The charging session simply continues from where it left off when power returns.

Which electric cars does this work with?

Any EV with a standard Type 1 or Type 2 inlet works, regardless of brand — Tesla, BMW, Volkswagen, Hyundai, Kia, Nissan, Renault, etc. Elewatt doesn't communicate with the car itself; it only controls the smart switch that supplies power to your charger.

What if I need to charge urgently when prices are high?

You can override the schedule at any time in the Shelly Smart Control app or directly on the plug's physical button. The device will stay on until you cancel the override. Elewatt pushes a new schedule each day, so the next day everything returns to normal automatically.

Does Elewatt control my EV or charger directly?

No. Elewatt sends on/off schedules to the Shelly smart plug that powers your charger. The charger and car operate completely independently — Elewatt only determines when electricity flows to the charger.

What if my car reaches 100% before the schedule ends?

No problem. Your car's battery management system stops accepting charge automatically when full. The charger idles at near-zero power. There is no risk of overcharging.

Education HubEV Charging Guide

EV Charging · Smart Automation

Smart EV Charging: Save money by charging at the right time

Electric vehicles consume 15–30 kWh per 100 km. At peak electricity prices, that can cost twice as much as charging during off-peak hours. In Estonia, Finland, Latvia, and Lithuania, Nord Pool spot prices fluctuate by 10–20× across the day — making smart scheduling one of the highest-impact changes you can make.

Get started free Connect Shelly

EV charging with smart electricity scheduling — Source: Google Gemini

Why does charging time matter?

Electricity spot prices in the Baltic and Nordic region change every hour. The difference between the cheapest and most expensive hour of the day typically ranges from 3–5× in summer to 10–20× in winter. An EV consuming 7.4 kW for 2 hours a day costs roughly:

At peak hours

~€1.00–2.50

per charge session

At off-peak hours

~€0.30–0.80

per charge session

Annual difference

€150–450

for a typical EV

Most EV chargers don't know what electricity costs right now. They just charge whenever you plug in. Elewatt changes that by pushing a daily on/off schedule to your smart relay so charging always happens during the cheapest window.

Choosing the right device

The right smart relay depends on your charger's power. Use the table below to find the correct device for your setup.

Use case	Max current	Device	Notes
Overnight trickle (≤2.5 kW)	12 A	Shelly Plug S Gen3	Plug & play, no installation
Standard charger (≤7.4 kW)	32 A single-phase	Shelly Plus 1PM	Requires wiring
3-phase 11 kW charger	3×16 A	TopAC EVE01-11R	Native Shelly device with REST API
Heavy 3-phase (up to ~33 kW)	3×32 A / 3×48 A	Shelly Pro 3	Professional install required

TopAC EVE01-11R — 3-phase 11 kW EV charger

The TopAC EVE01-11R is a Shelly ecosystem partner product available via shelly.com. It's a 3-phase 11 kW wall box with native REST API, MQTT, and Shelly Cloud support — meaning it's controlled in Elewatt exactly like any other Shelly device, using the same filter and schedule system.

This makes it the cleanest solution for 3-phase setups: no additional relay needed, and scheduling works out of the box.

How Elewatt automates your EV charging

1Connect your Shelly device in Elewatt (via Shelly Cloud or local IP).
2Create a duration filter: e.g. "4 hours between 23:00–07:00".
3Link the filter to your EV charger. Elewatt finds the cheapest 4-hour window and pushes the schedule to the device every evening.
4Plug in your car before bed. It charges automatically during the cheapest hours, every day.

Create a filter About Shelly Plug S Gen3 Connect Shelly

Calculate your savings

Adjust the sliders to match your EV's onboard charger power and typical daily charging time.

Savings Calculator

Estimate how much you could save by running your device during the cheapest hours.

Device power7.4 kW

0.1 kW22 kW

Hours per day2 h/day

1 h24 h

Days per year365 days

30 days365 days

Nord Pool EE + Elektrilevi grid + VAT · c/kWh (yearly avg)

0:00 · 14.1c

1:00 · 14.0c

2:00 · 13.1c

3:00 · 12.7c

4:00 · 12.6c

5:00 · 13.3c

6:00 · 16.2c

7:00 · 19.5c

8:00 · 21.8c

9:00 · 20.0c

10:00 · 17.8c

11:00 · 16.2c

12:00 · 15.6c

13:00 · 15.5c

14:00 · 15.5c

15:00 · 15.9c

16:00 · 16.7c

17:00 · 18.4c

18:00 · 20.9c

19:00 · 23.0c

20:00 · 23.7c

21:00 · 21.9c

22:00 · 18.7c

23:00 · 16.3c

Cheapest 2hMost expensive 2h

Daily usage

14.8 kWh/day

Annual usage

5402 kWh/year

With Elewatt

12.7 c/kWh avg

€683

per year

Without Elewatt

23.3 c/kWh avg

€1259

per year

Your savings

Monthly

€48

Yearly

€576

Shelly Plus 1PM (€35) pays back in
0.7 months

Based on Nord Pool EE spot prices 01.03.2025–01.03.2026 + Elektrilevi VÕ grid fee + excise tax + 24% VAT. "Without Elewatt" assumes running during the most expensive hours. Actual savings vary by country, grid, and season.