40 amp vs 48 amp charger for a BMW i4
For the trims below, EPA data shows the car accepts more than a 40 A charger delivers (9.6 kW). A 48 A charger (11.52 kW) saves up to about 1.7 hours on an empty-to-full charge (estimate). It needs a 60 A breaker instead of 50 A.
Per trim
| Trim | Empty→full at 40 A | Empty→full at 48 A | Miles per 8 h at 40 A | Miles per 8 h at 48 A | Why we think it accepts more |
|---|---|---|---|---|---|
| 2026 i4 eDrive40 Gran Coupe (18 inch wheels) | 9.9 h | 8.2–9.0 h | 269 mi | 323 mi (max) | EPA 240 V time implies an average of 10.5 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 eDrive35 Gran Coupe (19 inch Wheels) | 8.1 h | 6.7–7.0 h | 249 mi | 299 mi (max) | EPA 240 V time implies an average of 11.0 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 eDrive40 Gran Coupe (19 inch Wheels) | 9.9 h | 8.3–9.0 h | 247 mi | 296 mi (max) | EPA 240 V time implies an average of 10.6 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 xDrive40 Gran Coupe (18 inch Wheels) | 10.0 h | 8.3–8.0 h | 230 mi | 276 mi (max) | EPA 240 V time implies an average of 12.0 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 M60 xDrive Gran Coupe (19 inch Wheels) | 10.0 h | 8.3–9.0 h | 223 mi | 268 mi (max) | EPA 240 V time implies an average of 10.6 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 xDrive40 Gran Coupe (19 inch Wheels) | 10.1 h | 8.4–8.0 h | 213 mi | 256 mi (max) | EPA 240 V time implies an average of 12.1 kW, so it must accept more than 9.6 kW at times |
| 2026 i4 M60 xDrive Gran Coupe (20 inch Wheels) | 10.0 h | 8.3–9.0 h | 186 mi | 223 mi (max) | EPA 240 V time implies an average of 10.7 kW, so it must accept more than 9.6 kW at times |
Estimates: energy for the full EPA range (kWh/100 mi × range ÷ 100, at the wall) ÷ charging power. Where EPA states the onboard charger we cap at it. Otherwise the 48 A figure is a range: from full 11.52 kW down to the average power implied by EPA's 240 V time, because the true onboard limit isn't in EPA data. Real charging tapers near 100%. Vehicle data: fueleconomy.gov.
For the other 3 trim(s) EPA data doesn't show more than 9.6 kW being accepted, so a 48 A charger may not help them: 2025 i4 eDrive35 Gran Coupe (18 inch Wheels), 2025 i4 M50 Gran Coupe (19 inch wheels), 2025 i4 M50 Gran Coupe (20 inch wheels).
Does it matter day to day?
Most drivers plug in overnight and rarely charge from empty. Both chargers add 269+ miles in 8 hours for the most efficient qualifying trim. The 48 A option mainly helps with long daily drives, short charging windows on time-of-use plans, or sharing one charger between two cars. The bigger circuit can cost more to install (wire size, panel capacity), and that cost isn't in our data.
Certified chargers at each size
ENERGY STAR lists 20 featured 40 A and 26 featured 48 A chargers: 40 A chargers · 48 A chargers · breaker sizes. Most can be set to a lower current if your panel can't supply 60 A.
All BMW i4 charging times · Calculator
Not electrical advice; use a licensed electrician.