Electric vehicles

How many miles does one 23:30–05:30 charge add?

Last checked: 15 October 2026 · PlugLater

One overnight charge adds charger kW × hours × your car’s miles per kWh. On Intelligent Octopus Go’s six-hour window, 23:30 to 05:30, that is 13.8 kWh from a 2.3 kW three-pin lead and 44.4 kWh from a 7.4 kW wallbox, before losses. What that is in miles depends on the car.

The formula

kWh added = charger power (kW) × hours in the window. 2.3 kW × 6 h = 13.8 kWh. 7.4 kW × 6 h = 44.4 kWh.
Miles added = kWh added × miles per kWh. Miles per kWh is 1,000 ÷ the car’s Wh a mile.
If the battery is smaller than the kWh the charger can deliver, the limit is a full battery, not the window.
Charging losses are not included. Your meter will record more kWh than the battery takes in.

Ten cars, one six-hour window

Miles added between 23:30 and 05:30, before losses
Car (EV-Database real range)	mi/kWh	2.3 kW	7.4 kW	7.4 kW, cold weather
Tesla Model 3 RWD *	4.59	63	204	170
Tesla Model Y RWD *	3.92	54	174	144
Vauxhall Corsa Electric 54 kWh	4.03	56	179	148
Renault 5 E-Tech 52 kWh	4.03	56	179	150
MG4 Urban Comfort Standard Range	3.70	51	155 (full battery)	130
Nissan Leaf Standard Range 52 kWh	3.77	52	167	143
Kia EV3 Long Range *	3.58	49	159	134
BYD Atto 3 Evo RWD Design	3.34	46	148	125
MINI Cooper Electric Cooper E	4.24	59	155 (full battery)	130
Skoda Elroq 85	3.57	49	159	135

Miles per kWh comes from the same EV-Database figures as all 142 cars. The cold-weather column uses EV-Database’s combined cold-weather figure for each car (−10°C with heating on), a worst case rather than a typical winter night. Usable battery sizes are from each car’s EV-Database page; * marks a battery size EV-Database gives as an estimate. All checked 15 October 2026.

The MINI Cooper E (36.6 kWh usable) and the MG4 Standard Range (41.9 kWh) have batteries smaller than the 44.4 kWh a 7.4 kW wallbox can deliver in six hours, so even from empty they are full before 05:30.

Other windows

Not every EV tariff gives six hours. With a 7.4 kW wallbox, a five-hour window (Octopus Go, British Gas EV Power, So EV, ScottishPower EV Saver) adds 37.0 kWh, and EDF’s seven-hour window adds 51.8 kWh. On a 2.3 kW lead it is 11.5 kWh and 16.1 kWh. Windows and rates for each tariff, checked on the suppliers’ pages, are in UK EV tariffs compared.

Does it cover a week of commuting?

Take 30 miles a day, five days a week: 150 miles. Divide by the car’s miles per kWh for the energy you need, then by what one night adds.

Tesla Model 3 RWD: 150 ÷ 4.59 = 32.7 kWh. That is 2.4 nights on a 2.3 kW lead, or 0.7 of one night on a 7.4 kW wallbox.
Vauxhall Corsa Electric 54 kWh: 150 ÷ 4.03 = 37.2 kWh. 2.7 nights on a 2.3 kW lead.
Kia EV3 Long Range: 150 ÷ 3.58 = 41.9 kWh. 3.0 nights on a 2.3 kW lead, 0.9 nights on a wallbox.
Same EV3 week on its cold-weather figure (3.01 mi/kWh): 49.8 kWh, so 3.6 nights on a 2.3 kW lead.

So for a 150-mile week, a granny lead covers it in under four nights for all three cars, even on the cold figure. It starts to fall short for high mileages, which granny charger vs wallbox works through with a 20,000-mile example.

Winter

In cold weather the car uses more energy per mile, for heating and because a cold battery is less efficient. The same kWh then buys fewer miles: for the Model 3 RWD, a full six-hour wallbox window is 204 miles on the middle figure and 170 on the cold one. Charging also loses more energy at low power, so the 2.3 kW column is the most optimistic.

Work out your own week in the homepage EV calculator, which has a mileage slider and lets you type in your own rates.

Questions people ask

How many miles does 6 hours of charging add?

At 7.4 kW, six hours is 44.4 kWh. That is about 204 miles in a Tesla Model 3 RWD (4.59 mi/kWh) and 159 in a Kia EV3 Long Range (3.58 mi/kWh), before losses. From a 2.3 kW three-pin lead it is 13.8 kWh: about 63 and 49 miles.

How many miles does a granny charger add overnight?

About 46 to 63 miles in six hours at 2.3 kW for the ten cars on this page, before losses. On EV-Database’s cold-weather figures it is about 15–17% fewer.

Will one night fill my battery?

Only if the battery is smaller than what the charger can deliver: 44.4 kWh in six hours at 7.4 kW. Of the ten cars here, only the MINI Cooper E and MG4 Standard Range fill from empty in one six-hour window.

Is this financial advice?

No. It is arithmetic from EV-Database consumption figures and charger power, for planning only.

Not financial advice. These are worked examples from published rates and EV-Database consumption estimates, for planning only. Your own tariff, day rate, standing charge, car, driving and weather will change the numbers. Check your bill and your supplier’s current terms before you switch or buy anything.

Sources

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