Charging speeds explained
How long does it take to charge an electric car?
A short top-up can take minutes; a full charge can take many hours or more than a day. A 7kW home charger can replenish daily driving overnight, but the time depends on your starting charge, usable battery capacity and the power your car accepts. Here are worked examples to help you check your charging window.
Free · No obligation · Takes about 60 seconds
The short answer
Last reviewed: 26 October 2026
- A 7kW home charger supplies at most 7kWh per hour before losses.
- Power in kW multiplied by hours gives energy in kWh. Less reaches the battery after losses, and your car's AC limit can reduce the power drawn.
- An overnight top-up and a full charge are different jobs.
- A 60kWh usable battery needs 36kWh to go from 20% to 80%, but 60kWh from 0% to 100%. At a constant 7kW, allowing 10% extra energy for losses, those take about 5.7 and 9.4 hours respectively.
- A 3-pin plug delivers about 2.3kW, roughly three times slower than a fitted 7kW unit.
- A full charge can take more than a day. See our 3-pin (granny charger) guide for portable charging use and safety.
Check the hours you actually have. At a constant 7kW, a seven-hour window supplies at most 49kWh and an eight-hour window at most 56kWh, before losses. With our illustrative 10% extra-energy allowance, that adds about 44.5kWh or 50.9kWh to the battery. A lower AC limit, load sharing or a delayed start reduces the total.
Charge times by battery size
Choose the generic usable battery capacity closest to yours. The 7kW column shows home AC charging. These are arithmetic examples, not specifications for named cars. Each column assumes the car and supply can sustain the stated power; a wallbox advertised as 7.4kW will give slightly different figures if it delivers that rate.
| Usable battery capacity generic examples | 3-pin 2.3kW, 0 to 100% |
Home charger
Your driveway 7kW, 0 to 100% | Three-phase 22kW, 0 to 100% | Public rapid 50kW, 10 to 80% ideal minimum | Ultra-rapid 150kW, 10 to 80% ideal minimum |
|---|---|---|---|---|---|
| 40 kWh | ~19.1 hrs | ~6.3 hrs | ~2 hrs | ~34 min | ~11 min |
| 52 kWh | ~24.9 hrs | ~8.2 hrs | ~2.6 hrs | ~44 min | ~15 min |
| 60 kWh | ~28.7 hrs | ~9.4 hrs | ~3 hrs | ~50 min | ~17 min |
| 77 kWh | ~36.8 hrs | ~12.1 hrs | ~3.9 hrs | ~65 min | ~22 min |
| 100 kWh | ~47.8 hrs | ~15.7 hrs | ~5 hrs | ~84 min | ~28 min |
The maths. AC columns (2.3kW, 7kW, 22kW) show 0% to 100% using usable capacity × 1.1 ÷ power, rounded to 0.1 hour. DC columns show 10% to 80% using capacity × 0.7 ÷ power, rounded to a minute. For example, a 60kWh battery needs 42kWh for that DC top-up, giving an ideal minimum of about 50 minutes at 50kW. Actual DC charging takes longer when power drops or energy is lost.
Check your car's limits. AC and DC limits are separate. A high DC peak does not establish a home AC charging time. Use the AC specification for your exact model and version; 22kW AC also needs a three-phase supply. Battery temperature, starting charge and the charging curve affect the actual time.
Charging-time sources checked 26 October 2026: DfT on why rated power is not guaranteed, SEAI on vehicle limits and charging losses and Volvo on factors affecting charging time.
Now you know how long, the next question is how much. See what it costs to charge an electric car in NI and which overnight tariffs make it cheapest.
What each charging speed is, and where you meet it
The table above compares generic battery sizes. This one explains each charger type: what it is, and where in real life you come across it, from the slowest 3-pin trickle to the fastest public ultra-rapid. The one most NI drivers actually live with is highlighted.
| Charger | Power | 60kWh, 20 to 80% | Where you'll find it |
|---|---|---|---|
| 3-pin plug (granny charger) | ~2.3kW | ~17.2 hours | Any domestic socket. Emergency or occasional use only, never as your main method. |
| Home charger (7kW) NI sweet spot | 7kW | ~5.7 hours | A home wallbox on a single-phase supply. Check your car's AC limit and how much energy you need overnight. |
| Three-phase home charger (22kW) | 22kW | ~1.8 hours | Needs a three-phase supply most NI homes do not have, and many cars cap AC charging at 7kW to 11kW anyway. |
| Public rapid | 50kW | ~43 min (ideal minimum) | Motorway and forecourt units. Actual time depends on the car's DC limit and charging curve. |
| Public ultra-rapid | 150kW | ~14 min (ideal minimum) | Public units for shorter stops. The rated power is a ceiling; the car will not necessarily sustain it. |
Every time in this table covers 20% to 80% of a generic 60kWh usable battery, adding 36kWh. AC times assume 10% extra energy for losses. DC times are ideal minimums at constant power without losses or tapering; power can fall within this window too. These are not full-charge times or manufacturer claims.
Why 7kW overnight is the NI sweet spot
Match the charger to the energy you need and the hours available. For a home with single-phase supply, 7kW is a practical starting point.
It matches your supply
7kW runs on the standard single-phase supply almost every NI home already has. No expensive three-phase upgrade, no fuss.
It can cover daily top-ups
A 60kWh battery going from 20% to 80% takes about 5.7 hours at a constant 7kW with our loss allowance. Starting empty takes about 9.4 hours to reach full.
It pairs with cheap rates
A smart 7kW charger can schedule charging within your tariff window. Check that the window supplies the energy you need; a large top-up can require extra hours outside it.
Weighing 7kW against 22kW properly? Read our 7kW vs 22kW guide, see the best home chargers for NI, or check which NI tariffs make overnight charging cheap.
Stop watching the clock at public chargers
Ask the installer to check your car's AC limit, daily mileage, ready-by time and available charging window. We match you with up to three vetted, NICEIC-registered NI installers so you can compare and get fitted sooner.
- Up to 3 vetted, NICEIC-registered NI installers
- NIE Networks notification included as standard
- Your OZEV grant checked before you commit
- Advice on 7kW vs anything faster for your home
Not sure which unit? Start with the charger comparison.
Not ready for quotes yet? Estimate your install cost first.
Get 3 quotes for a 7kW home charger
No obligation. We match you with up to 3 NICEIC-registered installers covering your area.
Request received
Thanks for that. We're matching you with up to 3 NICEIC-registered installers covering your area.
What happens next
- We share your request with up to 3 vetted installers in your area.
- Each installer contacts you directly with their quote.
- You compare and choose. No obligation, and we never charge you.
Nothing more to do for now. Questions in the meantime? [email protected]
How long to charge an electric car: common questions
How long does it take to charge an electric car?
It depends on usable battery capacity, starting charge, the car's charging limit and losses. For a generic 60kWh battery, 20% to 80% adds 36kWh. Assuming 10% extra energy for AC charging losses, that takes about 17.2 hours at a constant 2.3kW or 5.7 hours at 7kW. Ideal DC minimums are about 43 minutes at 50kW or 14 minutes at 150kW, before losses or any reduction in power. These are arithmetic examples, not model-specific charging times.
How long does it take to charge an electric car with a 7kW charger?
For generic usable battery capacities from 0% to 100%, assuming a constant 7kW and 10% extra energy for losses: 40kWh takes about 6.3 hours, 60kWh about 9.4 hours, 77kWh about 12.1 hours and 100kWh about 15.7 hours. A lower vehicle AC limit or reduced power makes it slower. A partial top-up takes less time, but a full charge will not always fit overnight.
How long does it take to charge a car at home?
For a generic 60kWh usable battery at a constant 7kW, allow about 9.4 hours from 0% to 100%, or 5.7 hours from 20% to 80%, assuming 10% extra energy for losses. The same full charge at 2.3kW takes about 28.7 hours under that assumption. Check your car's AC limit, starting charge and available charging window before relying on an overnight top-up.
Why is a 7kW home charger the right choice for most NI homes?
A 7kW charger suits a single-phase home supply and can replenish daily driving during an overnight stop. Whether it reaches your target depends on the energy needed, your car's AC limit and the hours available. A 22kW charger needs three-phase and a car that accepts that AC rate; the wallbox rating alone does not guarantee faster charging.
How long does a 7kW charger take to fully charge a car?
A 7kW charger supplies at most 7kWh in one hour before losses. For a generic 60kWh usable battery, a full 0% to 100% charge takes about 9.4 hours at a constant 7kW if 10% extra energy is needed for losses. A 20% to 80% top-up adds 36kWh and takes about 5.7 hours with the same assumption. Seven hours supplies at most 49kWh and eight at most 56kWh before losses, so neither guarantees a full charge from empty.
Is a 22kW charger worth it at home?
Rarely, in Northern Ireland. Home 22kW charging needs a three-phase supply, which most NI houses do not have and which is expensive to install. Even with it, many EVs limit onboard AC charging to 7kW or 11kW, so the extra capacity sits unused. For nearly all homes a 7kW charger is the sensible, cost-effective choice. Our 7kW vs 22kW guide covers the decision in full.
How much range do I add per hour of charging?
Range depends on the car's energy consumption as well as charging power and losses. For illustration, if 10% extra energy is needed for charging and the car travels 4 miles per kWh, a constant 7kW adds about 25 miles per hour and 2.3kW about 8 miles. Cold weather or higher consumption reduces those figures. Calculate the energy needed for your own driving rather than assuming one night covers a full week.
Plan your overnight charge at home
Get up to three quotes for a 7kW home charger from vetted NI installers, grant checked, NIE Networks notification handled. No obligation, always free.
Free · No obligation · Takes about 60 seconds