How a battery car really works, from the lithium ions in one cell to the motor, the charger and the bill. Spin the X-ray car, scroll the power flow, and play with the charging, range and cost simulators.
An electric car has far fewer moving parts than a petrol one: a battery, an inverter, a motor and one gear. Scroll the steps and watch the power flow through the car, or pick a mode yourself.
Where the cable goes in. Most UK electric cars have a CCS2 socket: a Type 2 top half for everyday AC charging and two big pins underneath for rapid DC.
Mains electricity is AC, but batteries store DC. At home a charger inside the car converts it, usually at up to 7 or 11 kW. That is why a 22 kW post does not charge most cars any faster.
A rapid charger does the conversion in its own roadside cabinet and pushes DC straight into the battery at 50 to 350 kW, so the on-board charger sits this one out.
Thousands of lithium-ion cells in a flat tray under the floor, wired to about 400 V (800 V on some newer cars). Its size in kWh is the fuel tank: 40 to 100 kWh is typical. Low and heavy, it also keeps the car planted in corners.
The battery management system (BMS) watches the voltage and temperature of every cell. A coolant loop, often with a heat pump, keeps the pack near the 20 to 40 °C it likes.
The power brain. It switches the battery's DC into three-phase AC thousands of times a second. Changing the frequency changes the motor's speed; changing the current changes its torque.
Electromagnets in the stator pull the rotor round. Around 90% of the energy becomes motion, against roughly 30% in a petrol engine, and full torque is there from 0 rpm.
Motors spin to 16,000 rpm or more, so a single reduction gear of about 9:1 does the job. No clutch and no gear changes, which is why an EV counts as an automatic on a UK licence.
Lift off the pedal and the inverter turns the motor into a generator. The car slows down and the energy flows back into the battery, shown here in green.
A DC-DC converter steps the high voltage down to keep an ordinary 12 V battery charged for the locks, lights and screens. A flat 12 V battery can still leave an EV stuck.
Rounded from the US Department of Energy's fueleconomy.gov: petrol cars turn roughly 16 to 25% of the fuel's energy into motion, electric cars more than 77% of the energy from the grid.
The battery is the most expensive part of an EV, often a third of its cost. It is made of thousands of small cells, grouped into modules and sealed into one flat pack.
Round cylindrical cells are cheap to make by the billion. Flat prismatic cans and pouches pack tighter. The BYD Blade turns each long prismatic cell into part of the structure.
| NMC | LFP | Na-ion | |
|---|---|---|---|
| Range (energy density) | ●●●●● | ●●●●● | ●●●●● |
| Low cost | ●●●●● | ●●●●● | ●●●●● |
| Lifespan | ●●●●● | ●●●●● | ●●●●● |
| Cold weather | ●●●●● | ●●●●● | ●●●●● |
| Thermal safety | ●●●●● | ●●●●● | ●●●●● |
NMC · Nickel manganese cobalt. Most European, Korean and premium EVs. The most energy for its weight, so the longest range.
LFP · Lithium iron phosphate. Cheaper, cobalt-free and very long-lived. Common in standard-range Teslas, BYDs and MGs. Happy to be charged to 100%.
Na-ion · Sodium-ion. The newcomer: no lithium at all and good in the cold, but heavier. Arriving in small city cars from 2025.
Based on Geotab's study of more than 10,000 electric vehicles. Heat, lots of rapid charging and sitting at 100% speed ageing up; gentle home charging between 20 and 80% slows it down.
Electricity flows through copper coils in the stator one phase after another, making a magnetic field that rotates. Magnets on the rotor are dragged round with it. That is the whole trick.
Illustrative curves for a 150 kW electric motor and a 1.5-litre turbo petrol. Full torque from standstill is why even a small EV feels quick away from the lights.
Rare-earth magnets on the rotor. The most efficient type and the most common: almost every modern EV has at least one.
No magnets; the stator induces current in copper or aluminium bars on the rotor. Rugged and cheap, used by early Teslas and as the second motor on some dual-motor cars.
The rotor has its own electromagnets fed with current. No rare earths at all. Used by BMW and Renault.
A flat pancake motor with huge torque for its size. Built by YASA in Oxfordshire for supercars like the Ferrari SF90.
When you lift off, the motor runs backwards as a generator. It slows the car and turns movement back into charge, which is why EVs are at their most efficient in stop-start town traffic. Pick a regen level.
Two kinds of charging do two different jobs. Slow AC charging tops you up at home or work while the car is parked anyway; rapid DC charging is the motorway stop.
Granny cable for a normal socket. Fine now and then; use an outdoor-rated socket, never an extension reel.
The standard AC plug in the UK and Europe, used at home wallboxes and on-street posts.
Type 2 plus two large DC pins. The rapid connector on almost every new EV in the UK, Teslas included.
Japanese standard on older Nissan Leafs and Mitsubishi Outlanders. Being phased out at new UK sites.
Estimated from typical charging curves: AC charging is limited to 11 kW by most cars' on-board chargers, and rapid charging slows as the battery fills. Cold batteries charge slower. For the shape of a real charging curve, see the simulator on the Market & trends tab.
A wallbox fitted by an electrician costs roughly £800 to £1,200 and needs off-street parking. With an overnight EV tariff it is by far the cheapest way to run an EV. New home chargers in the UK must be "smart", so they can shift charging to quiet hours.
The official WLTP range is measured in a lab at mild temperatures. Speed and cold make the biggest difference: air drag grows with the square of speed, and heating the cabin takes real energy. Try it.
The opposite of a petrol car. At 70 mph most of the energy goes into pushing air, so dropping to 60 mph can add 10 to 15% range.
Expect 10 to 30% less in freezing weather. A heat pump, heated seats and pre-heating while plugged in claw most of it back.
The average car trip in England is under 10 miles. Even a small 40 kWh car covers a week of typical commuting on one charge.
Electricity price is everything. Charged at home on an overnight tariff an EV costs a fraction of petrol per mile; charged only on rapid chargers it can cost more.
Late-2025 UK averages, rounded: EV at 3.5 miles per kWh including charging losses, petrol at 134p and diesel at 142p a litre. Prices move, so check your own tariff.
Since April 2025 electric cars pay road tax: £10 in the first year, then the standard rate (£195 a year for 2025/26).
Cars with a list price over £40,000 pay about £425 a year extra in years 2 to 6. For electric cars the threshold rises to £50,000 from April 2026.
Since July 2025, up to £3,750 off eligible new electric cars that cost £37,000 or less. The dealer applies the discount.
The government plans an electric vehicle excise duty of 3p a mile for EVs (1.5p for plug-in hybrids) from April 2028, on top of VED.
Benefit-in-kind tax on a company EV is 3% of its value in 2025/26, rising by a point a year. That is why so many new EVs are company cars.
Flat owners and renters with their own parking can get up to £350 towards a home charger through the OZEV EV chargepoint grant.
Six ways to add electricity to a car, from a small helper motor to no engine at all. The orange lines show where the drive comes from.
ELECTRIC-ONLY RANGE · 0 miles
A 48 V starter-generator helps the engine pull away and lets it switch off sooner. Saves a little fuel; you drive it like any petrol car.
ELECTRIC-ONLY RANGE · 1–2 miles
Engine and motor share the work and the battery charges itself from braking. Toyota made these famous. Brilliant in town.
ELECTRIC-ONLY RANGE · 30–70 miles
A bigger battery you charge from a socket covers most commutes on electricity, with petrol for long trips. Only efficient if you plug it in.
ELECTRIC-ONLY RANGE · 100+ miles
An electric car with a small petrol engine that only makes electricity and never drives the wheels. Back in fashion with new Chinese and Mazda models.
ELECTRIC-ONLY RANGE · All of it
Battery and motor only. No oil changes, no exhaust, no gearbox. What most people mean by "an electric car".
ELECTRIC-ONLY RANGE · All of it
Makes its own electricity from hydrogen, and only water comes out of the back. Fills in 5 minutes, but the UK has only a handful of hydrogen stations.
An EV starts life with a bigger carbon debt, because making the battery takes a lot of energy. Then every mile on Britain's increasingly low-carbon grid pays it back.
Illustrative, in line with published life-cycle studies such as the ICCT's: about 7 t to build a petrol car and 11 t for an EV, then roughly 0.35 kg per mile for petrol fuel and 0.06 kg per mile for electricity from the UK grid.
Lithium, nickel, cobalt and graphite are mined, sometimes with real human and environmental costs. Cobalt-free LFP cells and better sourcing rules are reducing this.
Old car batteries can store solar power for years before recycling, which can recover most of the lithium, nickel and cobalt to make new cells.
No exhaust means no NO₂ at the kerb. EVs still make dust from tyres and roads, but regen means far less brake dust.
Driving an electric car is easy: it is an automatic with no engine noise. A few habits make it even better.
The car is on when the dash says READY. It can be completely silent, so check before you get out that it is in Park.
All the torque arrives at once. On wet or icy roads squeeze the pedal or you can spin the front wheels.
With strong regen you slow down just by lifting off. You still need the brake pedal for emergencies and to hold the car on a hill in some models.
New EVs must play a warning hum below about 12 mph. Pedestrians, especially children and blind people, may still not notice you in a car park.
EVs weigh 300 to 500 kg more than a similar petrol car. Leave space, and check weight limits on car park decks and trailers.
Warm the cabin and battery from the app before you leave. It uses mains power, not your range.
Most batteries prefer to live between 20 and 80%. Charge to 100% before a long trip. LFP batteries like a full charge every week.
It picks charging stops and warms the battery on the way so it charges faster. Apps such as Zapmap show every UK charger and whether it is working.
Electric cars are older than petrol ones, lost for a century, and are now winning again.
Scottish inventor Robert Anderson builds a crude electric carriage powered by non-rechargeable cells.
The Wolverhampton engineer who electrified the London Underground builds one of the first practical electric cars.
A bullet-shaped electric car driven by Camille Jenatzy becomes the first road vehicle to pass 100 km/h.
Around a third of the cars on American roads are electric: quiet, clean and no hand crank needed.
Cadillac's electric self-starter ends hand-cranking. Cheap petrol and Ford's Model T push electric cars aside for 80 years.
Britain runs the world's biggest fleet of electric vehicles, delivering milk silently before dawn.
General Motors leases a modern electric car in California, then recalls and crushes most of them.
The first mass-produced hybrid. It makes electric drive normal for millions of drivers.
Built from thousands of small lithium-ion cells like those in laptops, it shows an EV can do 200+ miles and be fun.
The first mass-market electric car. From 2013 it is built in Sunderland.
One proves an EV can be the best car in its class; the other becomes Europe's affordable electric best-seller.
The Porsche Taycan doubles the battery voltage so it can charge faster, followed by Hyundai and Kia.
The Tesla Model Y becomes the best-selling car of any kind on the planet.
A quarter of new cars sold worldwide plug in. In the UK, 23.4% are fully electric.
New pure petrol and diesel cars can no longer be sold in the UK. Hybrids follow in 2035.
The claims you will hear in the pub and online, checked against the evidence.
Electric cars are a fire risk.
THE FACTSData from Sweden, Norway and the US suggest EVs catch fire less often per car than petrol or diesel cars. A battery fire is harder to put out, which is why fire services train for them.
The battery wears out and costs a fortune.
THE FACTSMost packs lose only a little capacity each year: a study of more than 10,000 EVs found about 1.8% a year on average. Batteries usually carry an 8-year, 100,000-mile warranty.
Making the battery cancels out the benefit.
THE FACTSBuilding the battery does create more CO₂ at the start, but on the UK grid an EV typically pays that back within about 15,000 miles and ends its life with far lower total emissions.
Water and high voltage don't mix, so avoid both.
THE FACTSBattery packs and connectors are sealed and tested against water and dust. Charging in the rain and using automatic car washes are completely normal.
Cold weather kills EV range.
THE FACTSCold slows the chemistry and heating takes energy, so expect roughly 10 to 30% less range in freezing weather. Pre-heating while plugged in and a heat pump cut the loss.
You have to wait hours to charge.
THE FACTSCharging at home takes hours, but it happens while you sleep. On a rapid charger, 10% to 80% takes about 20 to 40 minutes on most new EVs.
EV drivers pay no road tax.
THE FACTSSince April 2025 electric cars pay Vehicle Excise Duty like other cars, and a pay-per-mile charge is planned from April 2028.
The National Grid will collapse.
THE FACTSMost charging happens overnight when demand is low, and smart chargers move it to quiet hours automatically. Britain's peak electricity demand is lower today than in the early 2000s.
EVs cost more to insure.
THE FACTSOften yes, especially for new drivers, because repairs need specialist skills and parts. The gap is closing as more garages train up.
EVs eat tyres.
THE FACTSThey are heavier and deliver torque instantly, so tyres can wear faster. Brake pads and discs last far longer, because regen does most of the slowing down.
You can't hear an EV coming.
THE FACTSAt low speed they are quiet, so every new EV must play a warning sound below about 12 mph. Above that, tyre and wind noise make them about as loud as other cars.
No driveway, no EV.
THE FACTSA home charger makes it far cheaper and easier. Many drivers without one manage with street, work and supermarket chargers, but public charging costs several times more per mile.
The words on spec sheets, charger screens and forums.
A learning aid, not buying or financial advice. Figures are rounded UK values from late 2025 and change over time.