EV Charging Schedule Optimization UK 2025: Smart Tariff Timer Guide

Your EV charger can automatically charge your car during the cheapest electricity hours, saving £400-£500 annually compared to standard rates. This comprehensive guide shows you exactly how to set up optimal charging schedules for every major UK smart tariff, maximizing savings while ensuring your car is always ready when you need it.

Why Charging Schedule Optimization Matters

Standard rate charging (24p/kWh average UK 2025):

• 10,000 miles per year = 2,857 kWh = £686 annually

Optimized off-peak charging (7p/kWh on smart tariffs):

• 10,000 miles per year = 2,857 kWh = £200 annually

Annual saving: £486

Over 5 years of EV ownership, that's £2,430 saved simply by scheduling charging to use cheap overnight electricity instead of charging whenever you plug in.

Understanding UK Smart Tariff Windows

Every major UK smart EV tariff offers drastically cheaper electricity during specific overnight windows:

Octopus Intelligent Go

• Cheap rate: 7p/kWh (23:30-05:30) = 6 hours
• Standard rate: 24.50p/kWh (rest of day)
• Smart slots: Additional cheap periods when grid is low-cost (Intelligent algorithm adds these)
• Best for: Tech-savvy users with compatible smart chargers

OVO Charge Anytime

• Cheap rate: Effectively 7p/kWh averaged
• Smart optimization: OVO finds cheapest 6 hours within your availability window
• You set: "Car must be charged by [time]"
• Best for: Set-and-forget convenience

British Gas Electric Drivers

• Cheap rate: 9p/kWh (00:00-05:00) = 5 hours
• Standard rate: 26p/kWh (rest of day)
• Fixed window: No smart optimization, simple fixed off-peak period
• Best for: Simplicity, no smart charger required

E.ON Next Drive

• Cheap rate: 8p/kWh (00:00-07:00) = 7 hours
• Standard rate: 25p/kWh (rest of day)
• Fixed window: Longer overnight period
• Best for: Larger batteries needing longer charging times

Scottish Power EV Saver

• Cheap rate: 7.5p/kWh (00:00-07:00) = 7 hours
• Standard rate: 24p/kWh (rest of day)
• Fixed window: Scotland-focused tariff
• Best for: Scottish EV owners

Optimal Scheduling Strategy by Tariff

Strategy 1: Octopus Intelligent Go (Most Advanced)

Setup Requirements:

• Compatible smart charger (Ohme, Wallbox, Zappi, Hypervolt, Pod Point)
• Octopus Intelligent app installed
• Charger linked to Octopus account
• Vehicle details entered (battery size)

Optimal Configuration:

1. Set departure time (most important setting):

   • Enter time you need car fully charged each day
   • Example: "7:00am weekdays, 9:00am weekends"
   • System works backward from departure to schedule charging

2. Set target charge level:

   • Daily commute: 80% (extends battery life, still gives safety margin)
   • Long journey next day: 100% (override for specific days)
   • Weekend: 60-70% (if you don't drive far)

3. Enable Intelligent charging:

   • App: Settings → Intelligent Charging → ON
   • This allows system to use cheapest slots (may start before 23:30 if grid is cheap)

4. Bump charge setting:

   • Set minimum charge level (e.g., 30%) in case you need to leave early
   • Car maintains this minimum, then completes charging before departure

Advanced Octopus Tips:

• Max Boost button: Charges immediately at standard rate if you need emergency top-up
• Planned drives: Set departure times for specific days (e.g., early airport run)
• Away mode: Disable charging when on holiday to avoid vampire drain top-ups

Real-world optimization (Bristol user, Tesla Model 3, 12,000 miles/year):

• Departure time: 7:30am weekdays (work commute)
• Target charge: 80% daily
• Actual charging window used: 23:45-04:15 (4.5 hours typical)
• Annual cost: £240 (includes occasional daytime rapid charges)
• vs Standard rate: £823
• Annual saving: £583

Strategy 2: OVO Charge Anytime (Simplest)

Setup Requirements:

• Compatible charger (Ohme is official partner, most smart chargers work)
• OVO account with Charge Anytime tariff
• Charger connected to OVO via app

Optimal Configuration:

1. Set ready-by time:

   • Tell OVO when car must be fully charged
   • Example: "Ready by 7am every day"
   • OVO finds cheapest 6 hours before this time

2. Set plugged-in window:

   • When you typically plug in (e.g., "Usually plug in by 8pm")
   • Gives OVO maximum flexibility to find cheap periods

3. Automatic optimization:

   • OVO manages everything remotely
   • You just plug in and walk away
   • System charges during cheapest periods before your ready-by time

OVO doesn't require:

• Setting target charge levels (always charges to full)
• Managing schedules yourself
• Thinking about it at all

Real-world optimization (Manchester user, Nissan Leaf, 8,000 miles/year):

• Plugs in: 6pm daily
• Ready-by time: 7am next morning
• OVO typically charges: 00:30-06:30 (finding cheapest 6 hours)
• Annual cost: £160
• vs Standard rate: £548
• Annual saving: £388

Strategy 3: British Gas Electric Drivers (Fixed Schedule)

Setup Requirements:

• Any smart charger with scheduling capability
• British Gas Electric Drivers tariff

Optimal Configuration:

1. Set charge start time:

   • 00:00 (midnight) via charger app or vehicle settings

2. Calculate required charging duration:

   • Typical overnight top-up: 3-4 hours (30-40% to 90%)
   • Full charge from low: 8-10 hours (needs to start earlier)

3. Use vehicle scheduling OR charger scheduling:

   • Vehicle scheduling: Set in car to charge 00:00-05:00
   • Charger scheduling: Set in charger app to activate 00:00-05:00
   • Don't use both (can conflict)

Important limitation: Only 5 hours of cheap electricity (00:00-05:00). If you need more than 5 hours to charge from low battery, you'll pay standard rate for additional charging time.

Real-world optimization (Leeds user, Kia e-Niro, 10,000 miles/year):

• Plugs in: Evening (8-10pm)
• Charger scheduled: 00:00-05:00
• Typical charging needed: 3-4 hours nightly
• Charges within cheap window: 95% of nights
• Annual cost: £257
• vs Standard rate: £686
• Annual saving: £429

Strategy 4: E.ON Next Drive (Extended Window)

Setup Requirements:

• Any smart charger
• E.ON Next Drive tariff

Optimal Configuration:

1. Utilize full 7-hour window:

   • Cheap electricity: 00:00-07:00
   • Longer than competitors (perfect for larger batteries)

2. Charger scheduling:

   • Set start time: 00:00
   • Set end time: 07:00
   • Or use departure time mode (ready by 7:30am)

3. Best for large-battery EVs:

   • Vehicles with 70kWh+ batteries benefit from longer window
   • Can fully charge even from very low without hitting standard rates

Real-world optimization (Birmingham user, Tesla Model Y Long Range, 15,000 miles/year):

• 75kWh battery, often arrives home at 20%
• Needs ~7 hours to full charge (7kW charger)
• E.ON 7-hour window perfect for needs
• Annual cost: £300
• vs Standard rate: £1,029
• Annual saving: £729

Vehicle Scheduling vs Charger Scheduling

You can set schedules in two places. Understanding the difference prevents conflicts.

Vehicle Scheduling (In Your Car's Settings)

Where: Car's infotainment system, usually under Charging or Departure Time

How it works:

• Car tells charger when it's willing to accept power
• Outside scheduled times, car refuses to charge even if charger is offering power

Advantages:

• ✅ Works with any charger (even public chargers)
• ✅ Goes with the car if you sell charger or move house
• ✅ Can set different schedules for weekdays vs weekends

Disadvantages:

• ❌ Less sophisticated than smart charger scheduling
• ❌ Can't respond to grid pricing signals
• ❌ Resets if car battery goes completely flat (12V system reset)

Best for: Simple fixed-time scheduling on British Gas, E.ON, Scottish Power tariffs

Charger Scheduling (In Smart Charger App)

Where: Smartphone app for your charger (Ohme, Wallbox, Zappi, etc.)

How it works:

• Charger controls when to offer power to vehicle
• Can integrate with smart tariffs for dynamic optimization
• Vehicle usually set to "charge immediately" (accepts whenever charger offers)

Advantages:

• ✅ Smart tariff integration (Octopus Intelligent, OVO)
• ✅ Dynamic response to grid pricing
• ✅ Load balancing with household consumption
• ✅ Solar PV integration (charge when solar available)

Disadvantages:

• ❌ Tied to specific charger
• ❌ Loses settings if you move house or change charger
• ❌ Requires good WiFi connectivity

Best for: Octopus Intelligent Go, OVO Charge Anytime, solar integration

Which to Use?

Recommendation:

• Octopus Intelligent Go: Use charger scheduling + Intelligent app (required for smart slots)
• OVO Charge Anytime: Use charger scheduling + OVO integration (required)
• British Gas/E.ON/Scottish Power: Either method works, vehicle scheduling is simpler
• Solar PV integration: Must use charger scheduling (Zappi Eco modes)

NEVER use both simultaneously - they can conflict, preventing charging entirely.

Advanced Optimization Strategies

Strategy 1: Preconditioning While Plugged In

Most EVs can precondition (pre-heat or pre-cool) cabin before you leave. Doing this while plugged in means you don't use battery energy.

Setup:

1. Set departure time in vehicle (not charger)
2. Enable preconditioning/cabin comfort
3. Set desired temperature
4. Car heats cabin 10-20 minutes before departure

Benefit: Leaves home with full battery AND warm/cool cabin (uses grid power, not battery)

Savings: In winter, preconditioning while plugged in saves 8-15% range compared to warming cabin during drive. For 60kWh battery, that's 5-9kWh or £1.20-£2.16 per cold morning on standard rates (£0.35-£0.63 on smart tariff).

Strategy 2: Charge to 80% Daily, 100% Before Long Journeys

Daily commute:

• Set target charge: 80%
• Extends battery life (less stress from staying at 100%)
• Reduces charging time by 15-20% (last 20% charges slower)
• Still gives plenty of safety margin

Before long journey:

• Override to 100% night before
• Maximizes available range
• Occasional 100% charges don't significantly impact battery life

How to set:

• Most EVs: Charging settings → Target charge level → 80%
• Override: Set 100% for specific nights (most cars remember this)

Strategy 3: Departure Time Optimization

Set your departure time 30-60 minutes earlier than you actually leave.

Why: Guarantees charging completes with buffer time. If charging is unexpectedly slow (cold weather reduces charging efficiency), you still have full charge.

Example:

• Actual departure: 8:00am
• Set departure time: 7:00am
• Charging completes by 7:00am
• Car sits fully charged 7:00am-8:00am
• You leave with 100% confidence

Strategy 4: Weekend Schedule Adjustment

Most smart chargers let you set different schedules for weekdays vs weekends.

Weekday schedule:

• Departure: 7:00am (work commute)
• Target charge: 80%
• Critical to complete on time

Weekend schedule:

• Departure: 10:00am (flexible morning)
• Target charge: 70% (don't need full charge for short weekend trips)
• Lower target = less charging time = more flexibility for cheap rates

Savings: Charging to 70% instead of 80% reduces weekly kWh by ~15%, saving £25-£40 annually.

Strategy 5: Holiday/Vacation Mode

When not using car for extended periods (holidays, business trips), adjust settings:

Don't:

• ❌ Leave plugged in with regular schedule (wastes electricity on vampire drain top-ups)
• ❌ Leave unplugged at high charge (battery management systems prefer mid-range)

Do:

• ✅ Charge to 50-60% before leaving
• ✅ Unplug completely
• ✅ Or disable scheduled charging in app
• ✅ Some chargers have "holiday mode" (suspends all charging)

Why: EVs lose 1-3% charge per week when parked (vampire drain). If plugged in with scheduling enabled, charger tops this up repeatedly, wasting electricity. Better to leave at 50-60% and accept small drain.

Troubleshooting Common Scheduling Issues

Issue 1: Car Didn't Charge Overnight

Possible causes:

A) Schedule conflict (vehicle vs charger):

• Check both vehicle schedule AND charger schedule
• Disable one (recommend using charger schedule only for smart tariffs)

B) Departure time not set correctly:

• Verify departure time in app
• Check AM/PM setting (common mistake)
• Some apps use 24-hour time (07:00 not 7:00am)

C) WiFi connectivity issue:

• Charger lost WiFi connection, couldn't receive scheduling commands
• Check charger status lights (most flash differently when offline)
• Restart charger (turn off circuit breaker 30 seconds)

D) Vehicle refused charging:

• Some EVs won't charge if cabin climate control is on (check vehicle settings)
• Charge port locking mechanism failed (unplug, replug cable firmly)

Issue 2: Charging Started During Expensive Hours

Possible causes:

A) Smart charging disabled:

• Octopus: Verify Intelligent Charging is ON in app
• OVO: Check Charge Anytime is active on your account

B) "Max Boost" or "Charge Now" accidentally activated:

• Overrides smart schedule, charges immediately at any rate
• Check app for active overrides

C) Insufficient cheap hours for full charge:

• If battery was very low and needs 8 hours but only 6 hours of cheap rate available
• System may start charging early (partially at standard rate) to ensure ready by departure
• Solution: Charge more frequently (don't let battery get too low)

Issue 3: Car Only Charged to 60% Not 100%

Possible causes:

A) Target charge limit set in vehicle:

• Check vehicle charging settings (many default to 80%)
• Ensure 100% selected if you need full charge

B) Charger schedule ended before complete:

• Arrived home late with low battery
• Needed 7 hours but only 5 hours of cheap rate remaining
• Solution: Set earlier departure time, or charge will complete at standard rate

C) Charger reduced rate due to high household load:

• Load balancing charger detected high household usage
• Reduced charge rate to prevent tripping main fuse
• Solution: Reduce overnight household load (turn off electric heating overnight?)

Issue 4: Octopus Intelligent Isn't Adding Smart Slots

Possible causes:

A) Not enough flexibility in schedule:

• If you set departure time as 6:00am, no time for smart slots before 23:30 cheap period
• Solution: Set earlier plug-in time and later departure (gives system more flexibility)

B) Grid pricing hasn't been cheap outside normal window:

• Smart slots only added when grid prices are exceptionally low
• In winter (high demand), fewer smart slots available
• Summer (more renewables) has more smart slots

C) Charger not fully compatible:

• Some chargers have limited Intelligent Go features
• Check Octopus website for "fully compatible" vs "basic compatible" chargers

Seasonal Optimization Adjustments

Winter Optimization (November-February)

Challenges:

• Cold batteries charge 10-20% slower
• Preconditioning uses more energy
• Higher household usage (heating) can conflict with EV charging

Adjustments:

1. Earlier departure time: Set 60-90 minutes earlier than actual departure (allows for slower charging)
2. Precondition while plugged in: Critical for saving battery energy in cold weather
3. Charge to 90-100%: Cold weather reduces real-world range, so charge higher
4. Check load balancing: If you have electric heating, may need to charge vehicle after heating schedule ends

Example winter schedule:

• Plug in: 7:00pm
• Heat switches off: 11:00pm (smart heating schedule)
• EV charging starts: 00:00am (after heating finishes)
• Departure time set: 6:00am (actual departure 7:30am - allows buffer)
• Preconditioning: 7:10am (20 minutes before actual departure)

Summer Optimization (May-August)

Opportunities:

• Warmer batteries charge faster
• Less household heating usage
• More solar PV generation (if you have panels)
• More Octopus Intelligent smart slots (more renewable generation)

Adjustments:

1. Lower target charge: 70-75% sufficient for most daily driving (faster charging)
2. Solar charging: If you have panels, enable Zappi Eco/Eco+ mode for daytime charging
3. Departure time flexibility: Can set actual departure time (less buffer needed)
4. Smart slot opportunity: Earlier plug-in captures more cheap smart slots

Example summer schedule:

• Plug in: 5:00pm (home from work)
• Solar charging: 5:00pm-8:00pm (Zappi Eco mode, evening sun)
• Smart slots: May activate 9:00pm-11:00pm if grid is cheap
• Standard cheap period: 23:30-05:30
• Departure time: 7:15am (actual departure 7:30am)
• Target charge: 75% (sufficient for 40-mile commute)

ROI: Does Schedule Optimization Really Save Money?

Case Study: Typical UK EV Owner

Profile:

• Vehicle: Nissan Leaf (40kWh battery)
• Annual mileage: 10,000 miles
• Efficiency: 3.5 miles/kWh
• Annual consumption: 2,857 kWh
• Home charger: Ohme Home Pro (£850 installed)

Scenario A: No optimization (standard rate 24p/kWh)

• Annual cost: £686
• Over 5 years: £3,430

Scenario B: Basic optimization (British Gas 9p/kWh overnight)

• Annual cost: £257
• Annual saving: £429
• Over 5 years: £1,285 vs standard = £2,145 saved

Scenario C: Advanced optimization (Octopus Intelligent 7p/kWh + smart slots)

• Annual cost: £200
• Annual saving: £486
• Over 5 years: £1,000 vs standard = £2,430 saved

Additional benefit: £850 Ohme Home Pro charger pays for itself in:

• Basic optimization: 2.0 years (£429/year saving)
• Advanced optimization: 1.7 years (£486/year saving)

After payback, you pocket £400-£500 every single year for the life of the vehicle.

Quick Reference: Best Setup by Scenario

Scenario 1: "I want simplest possible setup"

Tariff: British Gas Electric Drivers (9p/kWh 00:00-05:00) Charger: Any smart charger, set schedule 00:00-05:00 Alternative: Use vehicle scheduling (even simpler, no charger app needed) Annual cost (10k miles): ~£257 Setup time: 5 minutes

Scenario 2: "I want maximum savings"

Tariff: Octopus Intelligent Go (7p/kWh + smart slots) Charger: Ohme Home Pro (best Octopus integration) Setup: Link Ohme to Octopus, set departure time, enable Intelligent Annual cost (10k miles): ~£200 Setup time: 15 minutes

Scenario 3: "I have solar panels"

Tariff: Octopus Intelligent Go (cheap overnight) or Octopus Agile (dynamic pricing) Charger: Zappi v2 (best solar integration) Setup: Zappi Eco+ mode for solar charging, plus smart tariff scheduling Annual cost (10k miles): ~£100-£150 (50% solar, 50% cheap overnight grid) Setup time: 30 minutes (solar CT clamp setup)

Scenario 4: "I drive unpredictable miles"

Tariff: OVO Charge Anytime (7p/kWh effective, flexible) Charger: Ohme (official OVO partner) or any smart charger Setup: Tell OVO your ready-by time, system handles rest Annual cost (10k miles): ~£200 Setup time: 10 minutes

Scenario 5: "I have large battery EV"

Tariff: E.ON Next Drive (8p/kWh 00:00-07:00 = 7 hours) Charger: Any 7kW smart charger Setup: Use full 7-hour window for large battery charging Annual cost (10k miles): ~£229 Setup time: 5 minutes

Conclusion: Set It Once, Save Forever

Optimizing your EV charging schedule takes 10-30 minutes to set up correctly but saves £400-£500 every single year. Over typical 5-year EV ownership, that's £2,000-£2,500 in your pocket just for plugging in at night instead of charging at expensive daytime rates.

Key takeaways:

1. Choose the right tariff: Octopus Intelligent Go or OVO Charge Anytime for maximum savings
2. Use charger scheduling: More sophisticated than vehicle scheduling for smart tariffs
3. Set departure time accurately: Ensures car is always ready when you need it
4. Charge to 80% daily: Faster charging, longer battery life, still plenty of range
5. Precondition while plugged in: Saves battery energy in winter
6. Adjust seasonally: Winter needs more buffer time, summer allows more flexibility

Ready to optimize? Start with your tariff choice (Octopus Intelligent Go recommended for most UK users), set up your charger's scheduling, and let the savings accumulate automatically. After initial setup, you'll never think about it again - just plug in and save.