The i4 eDrive40 takes 28 minutes from 10 to 80 per cent on DC and about 8.2 hours to fill at home on an 11 kW wallbox. At the US average rate that is roughly $16.62 for a full charge and $5.24 per 100 miles – about a third of what the same distance costs in petrol.
How long it takes to charge
| Where | Power | Time | What that is |
|---|---|---|---|
| Home, Level 1 | 1.4 kW | ≈ 63 hours est | Empty to full on a 120 V household outlet at 12 A — suited to daily top-ups; a full charge can take days |
| Home, Level 2 | 7.7 kW | 11.7 hours | Empty to full, overnight |
| Home, Level 2 | 11.0 kW | 8.2 hours | Empty to full, overnight capped by the 11.0 kW onboard charger |
| Public DC, at its peak | 205 kW | 28 min | 10 to 80 per cent — the figure to compare cars on |
| Public DC station | 50 kW | ≈ 68 min est | 10 to 80 per cent, held back by the station |
| Public DC station | 150 kW | ≈ 28 min | 10 to 80 per cent — the car reaches its own limit here, not the station |
| Public DC station | 350 kW | ≈ 28 min | 10 to 80 per cent — the car reaches its own limit here, not the station |
What it costs to charge
| Charging at | Rate | Full charge | Per 100 miles |
|---|---|---|---|
| Home | $0.184/kWh | $16.62 | $5.24 |
| Public DC fast charging | $0.48/kWh | $39.02 | $13.68 |
| A petrol car, for comparison | $4.07/gal | — | $15.07 |
Assumptions, all editable in the running-cost calculator: $0.184/kWh at home (EIA US residential average) and $0.48/kWh on public DC, against petrol at $4.07 a gallon and 27 mpg. Charging is about 90 per cent efficient, so putting 81.3 kWh into this battery costs 90.3 kWh at the meter — 9.0 kWh that never reaches the pack. The rated consumption figures are measured at the wall already and need no such correction.
Over 13,500 miles a year — the US average — that is $707.94 of electricity charging at home, against $2,035.00 of petrol in the comparison car: a difference of $1,327.06 a year.
It wins on efficiency, not on charging
The i4 peaks at 205 kW, which sounds close to the 800-volt Korean cars and is not: it reaches its 28-minute window at a 150 kW station and gains nothing from a 350 kW one. On charging speed alone it is unremarkable.
What makes it cheap to run is the other half of the equation. At 28.5 kWh per 100 miles it is among the more frugal cars here, and cost per mile is efficiency multiplied by tariff – pack size and charger power do not enter into it. Over 13,500 US miles a year that is about $707 of electricity against roughly $2,034 of petrol in a 27 mpg car.
It is also why the i4 posts 525 km of observed real-world range — second only to the Tesla Model 3 Long Range — from an 81.3 kWh pack that several rivals beat on paper. Efficiency does the work twice: once at the plug and once on the road.
The 400-volt architecture costs it ten minutes
Against a Hyundai Ioniq 5 the i4 gives up ten minutes at every rapid stop – 28 against 18. That is the 400-volt pack talking, and no charger fixes it. Whether ten minutes a handful of times a year outweighs a running cost this low is a question about your driving, not about which car is better.
The full field ranked on that window is on fastest-charging electric cars, and why the peak kW figure misleads is in what a 10-80% charge time tells you.
Miles of range per hour, at every charger
The tables above answer “how long does a full charge take”. The question most drivers actually have at a plug is different: how much range goes in per hour, and how long until the next 100 miles are on the clock. This table answers that for every kind of charger, from a household 120-volt outlet to a 350 kW station, using the same figures as the rest of the page — the EPA’s 28.5 kWh per 100 miles, which is measured at the wall, and the measured 28-minute 10-80 per cent time. Rated range is used throughout; in winter, or at motorway speed, every row shrinks by the same proportion.
| Charger | Power at the car | Miles per hour | Add 100 mi | Empty to full | What sets the rate |
|---|---|---|---|---|---|
| Household outlet, Level 1 (120 V, 12 A) | 1.4 kW | 5 mi/h | 19 h 48 min | 62 h 44 min | the EPA figure, measured at the wall |
| Home wallbox, Level 2 | 7.7 kW | 27 mi/h | 3 h 42 min | 11 h 44 min | the EPA figure, measured at the wall |
| Home wallbox, Level 2 | 11.0 kW | 39 mi/h | 2 h 35 min | 8 h 13 min | capped by the 11.0 kW onboard charger |
| Public DC station | 50 kW | 205 mi/h | 29 min | — | held back by the station (estimate) |
| Public DC station | 150 kW | 499 mi/h | 12 min | — | the car’s own 28-minute 10-80 curve is the limit |
| Public DC station | 350 kW | 499 mi/h | 12 min | — | the car’s own 28-minute 10-80 curve is the limit |
A Level 1 outlet adds about 5 miles an hour — 51 miles in a ten-hour overnight stop, enough for a commute and not for much else. A 7.7 kW wallbox raises that to 27 miles an hour, so 100 miles takes 3 h 42 min and the car is full from empty in 11 h 44 min. On DC the useful figure is 499 miles an hour at a 150 kW post, and a 350 kW station does not raise it because the car’s own curve is the limit from 150 kW up — 100 miles in 12 min. The 50 kW row is the one to remember on a road trip: the station, not the car, sets the pace, and 100 miles takes 29 min.
The per-hour figures do not change with your electricity price, but the cost of every hour does: the residential rate runs from 13.11 cents a kWh in Nevada to 52.72 in Hawaii (EIA, June 2026). We publish the arithmetic for this car in every state — Missouri, Montana, Nebraska, Nevada — and a 50-state table ranked cheapest first.
Where these numbers will mislead you
Public charging changes the answer. On DC at $0.48/kWh the i4 costs $13.68 per 100 miles – still under petrol, but the home rate is most of the case for the car. If you cannot charge at home, run it again in the running-cost calculator.
Cold. The 28 minutes assumes a battery at a sensible temperature. A cold pack charges slower, and a cold cabin uses more of what you put in.
Frequently asked questions
How long does it take to charge a BMW i4?
About 28 minutes from 10 to 80 per cent on a 150 kW or faster DC station, and roughly 8.2 hours from empty on an 11 kW home wallbox – around 11.7 hours on a 7.7 kW supply.
How much does it cost to charge a BMW i4?
About $16.62 for a full charge at the US average residential rate, or roughly $5.24 per 100 miles – around $707 a year over average US mileage, against roughly $2,034 of petrol. EV versus petrol, worked through takes that beyond the fuel bill.
Do I need a 350 kW charger for a BMW i4?
No. It peaks at 205 kW and reaches its full 10-80 speed on a 150 kW station, so a faster post buys it nothing.
How many kWh does it take to fully charge a BMW i4 eDrive40?
The pack holds 81.3 kWh usable, but you pay for what comes out of the wall, and AC charging is roughly 90 per cent efficient — so a full charge draws about 90 kWh. That is the figure your electricity bill sees, and it is why the full-charge cost above is higher than capacity multiplied by tariff would suggest.
The same arithmetic across every car on this site: how many kWh a full charge really takes, 7.7 kW against 11.5 kW at home, and what charging costs per month.
Sources
Figures are credited individually on the BMW i4 eDrive40 page. Tariff assumptions are on the methodology page.