How to Set Up Your EV Charger to Charge During Off-Peak Hours

How to Set Up Your EV Charger to Charge During Off-Peak Hours (Step-by-Step)

One of the biggest financial benefits of owning an electric vehicle in Ireland is charging during off-peak hours when electricity rates drop by up to 75%. However, many new EV owners aren't sure how to configure their home charger to take advantage of these savings automatically.

If you have a smart EV charger like the Zappi or Ohme Home Pro installed at your home, setting up scheduled off-peak charging takes just a few minutes. Once configured, your charger will automatically wait until electricity prices drop before starting to charge, saving you hundreds of euro per year without any daily effort.

This guide walks you through the exact steps to set up off-peak charging for both Zappi and Ohme chargers, including troubleshooting tips for when your schedule doesn't work as expected.

What You Need Before You Start

Before configuring your charger, gather the following information:

Your Electricity Tariff Details

You need to know your exact off-peak hours. These vary by supplier and tariff type. At the time of writing, common Irish off-peak windows include:

Check your supplier's website or recent bill to confirm your specific off-peak window. See our comparison of night rate electricity times in Ireland for more detail.

Your Charger App Login

Ensure the myenergi app (for Zappi) or Ohme app is installed on your phone and you can log in successfully. If you haven't set up your account yet, you'll need your charger serial number (found on the unit itself).

Your Vehicle's Scheduled Charging Settings

This is critical: disable any scheduled charging settings in your car's built-in system. Your EV and your home charger both have scheduling features, and if both are active they will conflict. Always schedule charging through the charger app, not the vehicle.

Zappi Setup: Configuring Off-Peak Charging

The Zappi EV charger offers several charging modes. For off-peak charging, you'll use Eco+ mode combined with a Boost Timer schedule.

Step 1: Set Zappi to Eco+ Mode

Open the myenergi app and ensure your Zappi is set to Eco+ mode. This mode tells the charger to wait for your command before charging, rather than starting immediately when you plug in.

In the app:

• Tap on your Zappi device
• Select Eco+ from the charging mode options (not Fast or Eco)
• Eco+ will now show as the active mode

Eco+ mode is essential because it prevents the charger from starting immediately. If you're in Fast mode, the car will begin charging the moment you plug in, regardless of any timers you've set.

Step 2: Create a Boost Timer Schedule

A Boost Timer tells the Zappi exactly when to charge. This overrides the Eco+ "wait" instruction during your off-peak window.

In the myenergi app:

• Navigate to Other Settings → Boost Timer
• Tap Add Schedule
• Enter the following details:
  • Start Time: Match your off-peak start time (e.g., 11pm for SSE Smart EV Max)
  • Duration: Match your off-peak window (e.g., 6 hours for 11pm – 5am)
  • Days: Select which days this applies (typically every day, or weekdays only if you don't commute weekends)
  • Charge Amount: Set to a high kWh value (e.g., 50 kWh) or leave as maximum to ensure the car fully charges during the window
• Save the schedule

Your Zappi will now wait in Eco+ mode when you plug in during the day, then automatically start charging at your scheduled time.

Step 3: Test Your Schedule

Plug in your EV during daytime or early evening (before your off-peak window). The Zappi should not start charging immediately. Instead, the app should show "Waiting for Boost" or display the scheduled start time.

When your scheduled start time arrives (e.g., 11pm), the charger should automatically begin charging. Check the app or the charger's LED display to confirm charging has started.

If charging starts immediately when you plug in, your car's internal scheduling may be overriding the Zappi. Go into your vehicle settings and disable any scheduled charging features.

Zappi Troubleshooting: Why Your Schedule Didn't Work

Charging started immediately when I plugged in

• You're in Fast mode instead of Eco+ mode. Switch to Eco+ in the app.
• Your car's internal charging schedule is active. Disable vehicle-based scheduling.

Charging didn't start at the scheduled time

• Check that the Boost Timer is saved and shows in the app schedule list.
• Ensure your Zappi has a stable Wi-Fi connection (the timer runs locally but syncs via Wi-Fi).
• Confirm the car is still plugged in and the charging port is locked.

Charging stopped before the car was full

• Your kWh limit in the Boost Timer was too low. Increase the charge amount to 50+ kWh or set to maximum.

Ohme Setup: Configuring Smart Tariff Charging

The Ohme Home Pro is designed specifically for smart tariff optimisation. Setup is slightly simpler than Zappi because Ohme automatically calculates the cheapest charging windows once you input your tariff.

Step 1: Enter Your Electricity Tariff in the Ohme App

Open the Ohme app and navigate to Settings → Energy Tariff.

Select your supplier and tariff from the list. At the time of writing, Ohme supports:

• SSE Airtricity Smart EV Max
• Electric Ireland EV Night Boost
• Energia EV tariff
• Bord Gáis Energy standard and EV rates
• Custom tariff (if yours isn't listed)

If your tariff isn't pre-loaded, select Custom and manually enter:

• Off-peak start time
• Off-peak end time
• Day rate cost per kWh
• Night rate cost per kWh

Ohme uses this information to schedule charging during your cheapest hours automatically.

Step 2: Set Your Charging Preferences

In the Ohme app home screen, you'll see options for each charging session:

Smart Charge (Recommended for off-peak) This mode tells Ohme to charge during the cheapest hours within your off-peak window.

• Plug in your vehicle
• In the app, select Smart Charge
• Set Ready By Time (e.g., 7am if you leave for work at 8am)
• Ohme will automatically schedule charging during your off-peak window to ensure the car is ready by your departure time

Max Charge Use this if you need to charge immediately regardless of tariff (e.g., emergency top-up before an unexpected journey). This bypasses scheduling.

Schedule For recurring daily schedules (e.g., charge every night from 11pm – 5am), go to Settings → Schedules and create a recurring charge plan with your off-peak times and ready-by time.

Step 3: Enable Price Cap (Optional)

If you're on a dynamic tariff where prices change daily (e.g., Energia's dynamic plan), Ohme can set a Price Cap. This tells the charger to only charge when electricity drops below a certain price per kWh, even within your standard off-peak window.

To enable:

• Go to Settings → Price Cap
• Enter your maximum acceptable price (e.g., €0.15/kWh)
• Ohme will only charge when prices drop below this threshold

This feature is particularly useful during windy nights when wholesale electricity prices drop close to zero.

Step 4: Test Your Smart Charge

Plug in your EV during the afternoon or early evening. The Ohme app should display:

• Current status: Waiting to charge
• Scheduled start time (e.g., "Charging starts at 11:00 PM")
• Estimated finish time
• Total cost for the session

When the scheduled time arrives, charging should begin automatically. The app will update to show Charging status and live kW delivery.

Ohme Troubleshooting: Why Your Schedule Didn't Work

Ohme started charging immediately

• You selected Max Charge instead of Smart Charge. Use Smart Charge for scheduled off-peak sessions.
• Your ready-by time is set too early (e.g., ready by 6pm today when it's already 5pm). Ohme charges immediately if it can't fit the required charge into the future window.

Ohme didn't start charging at off-peak time

• Check Wi-Fi connection. Ohme requires internet to calculate schedules.
• Verify your tariff settings are correct in the app.
• Ensure the vehicle's charge port is unlocked and ready to accept charge.

The app says "Unable to connect"

• Your Ohme charger may have lost Wi-Fi. Check router signal strength near the charger location. See our guide on EV charger app connectivity issues.

What If You Switch Electricity Suppliers?

If you change to a different supplier or tariff, you must update your charger settings to match the new off-peak hours.

For Zappi:

• Go to Other Settings → Boost Timer
• Edit your existing schedule or delete and create a new one with updated times
• Save changes

For Ohme:

• Go to Settings → Energy Tariff
• Select your new supplier or update the custom tariff times
• Ohme will automatically adjust future charging schedules

Failing to update these settings means your charger will start at the wrong time and you'll pay peak rates instead of off-peak rates.

How Much Can You Save with Off-Peak Charging?

Setting up off-peak charging correctly can cut your EV charging costs by 50-75% compared to charging at standard day rates.

Example savings for a typical Irish EV driver (15,000 km per year, 18 kWh/100 km):

Over 5 years, off-peak charging saves over €4,500 compared to standard rates. Nearly half the cost of the EV charger installation itself. See our detailed breakdown of EV charging costs in Ireland.

Combining Off-Peak Charging with Solar

If you have solar panels installed, you can further reduce charging costs by combining daytime solar charging with off-peak grid charging.

For Zappi with Solar: Use Eco mode (not Eco+) during sunny days. Zappi will charge using surplus solar generation automatically. Then switch to Eco+ mode with a Boost Timer for overnight off-peak charging on cloudy days or in winter.

Alternatively, use Eco+ mode permanently and let the Boost Timer handle overnight charging, while manually triggering a solar boost on sunny afternoons using the app's Manual Boost button.

For Ohme with Solar: Ohme doesn't directly integrate with solar generation monitoring. However, you can manually trigger a Max Charge session during sunny midday periods when your solar system is producing surplus energy, then return to Smart Charge mode for overnight off-peak sessions.

For homes with both solar and EVs, the Zappi is specifically designed for solar integration and can automatically prioritise solar charging when available.

Final Thoughts

Configuring your EV charger for off-peak charging is one of the simplest ways to cut your annual charging costs by hundreds of euro. Once set up, the process is entirely automatic—you simply plug in whenever convenient, and the charger waits until electricity prices drop before starting.

The key steps are:

• Know your exact off-peak hours for your tariff
• Set Zappi to Eco+ mode with a Boost Timer, or Ohme to Smart Charge mode
• Disable any scheduling in your vehicle settings
• Test the schedule to confirm it works before relying on it daily

If you encounter issues, most problems stem from conflicting vehicle schedules, incorrect mode selection, or Wi-Fi connectivity. Refer to the troubleshooting sections above or contact your installer for support.

Need Help Setting Up Your EV Charger?

WattCharger installs and configures smart EV chargers across Ireland, with full setup support included. Our SEAI-registered installers ensure your Zappi or Ohme is correctly configured for your specific tariff and usage pattern, and we provide ongoing technical support after installation.

Whether you're installing a new charger or need help optimising an existing setup, get in touch with WattCharger for expert advice and professional installation. We'll handle everything from tariff configuration to app setup, so you start saving from day one