2027 Mercedes CLA Electric Fast-Charging Test Results
Independent testing of the 2027 Mercedes-Benz CLA 350 4MATIC Electric shows its DC fast-charging performance on Electrify America and Ionna networks
The 2027 Mercedes-Benz CLA 350 4MATIC Electric achieved a peak charging power of 352 kilowatts during a recent test, exceeding its manufacturer's 320 kW claim. The vehicle was tested from 0% to 100% state of charge at both an Electrify America and an Ionna charging station.
Vehicle Specifications
The 2027 CLA 350 4MATIC Electric is built on an 800-volt architecture and has an 85 kWh battery. Its EPA Combined range is rated at 312 miles, though a 70-mph highway test with optional 19-inch wheels yielded 385 miles. The car comes with a native NACS (SAE J3400) port for DC fast charging and a separate J1772 port for AC charging. Mercedes states a 10-80% charge should take 22 minutes, delivering an average range replenishment rate of 9.9 miles per minute based on the EPA rating.
Charging Session Analysis
State of Charge conducted two full charging sessions. The first was at a 350-kW Electrify America station using a CCS1-to-NACS adapter, as the battery was not preconditioned. The second test occurred at a 400-kW Ionna charger with a preconditioned battery and a direct NACS connection. All data was taken from the charger displays.
The charging curve showed a high initial peak followed by a rapid decline, a pattern the report compares to Tesla's approach. At Electrify America, power surged past 350 kW briefly before stabilizing at lower levels.
| Parameter | Electrify America Session | Ionna Session |
|---|---|---|
| Peak Power | 352 kW | 345 kW |
| Energy Delivered | 95.9 kWh | 95 kWh |
| 0-100% Time | 52 minutes | 53+ minutes |
| 10-80% Time | ~26 minutes | ~26 minutes |
| Avg. Power (10-80% SOC) | 155 kW | Not Specified |
Range Replenishment Performance
The core metric for drivers is how quickly miles are added back to the range estimate. The tests measured this against both the EPA rating and the real-world 70-mph test result.
Using the EPA Combined range of 312 miles, the average replenishment rate in the first 10 minutes at the Electrify America charger was 11.8 miles per minute. This added 118 miles of range. Performance dropped in subsequent 10-minute blocks.
When applying the 70-mph test result of 385 miles, the rate was proportionally higher. The first 10 minutes added range at 14.5 miles per minute.
| Range Basis | 0-10 min Rate | 10-80% SOC Avg. Rate | 0-70% SOC Avg. Rate |
|---|---|---|---|
| EPA Combined (312 mi) | 11.8 mi/min | 8.4 mi/min | 9.4 mi/min |
| 70-mph Test (385 mi) | 14.5 mi/min | 10.4 mi/min | 11.6 mi/min |
The 0-70% SOC average of 11.6 mi/min for the 70-mph range beat the manufacturer's spec of 9.9 mi/min. In practical terms, the test showed adding 100 miles of 70-mph range takes about 5.8 minutes.
Charging Network Compatibility
The vehicle was tested on two major charging networks. Electrify America, founded by Volkswagen Group of America in 2017, provided a 350-kW DC fast charger. The newer Ionna network, established in 2024 by a consortium of seven automakers including BMW, General Motors, and Mercedes-Benz, provided a 400-kW unit. The report noted very similar performance between the two, with the main difference being a slightly lower peak power at the Ionna station despite battery preconditioning.
The tests confirm the CLA Electric's ability to access high-power chargers across different networks. Its onboard voltage booster allows it to use 400-volt-class chargers, though at potentially limited power. The full charging session took just under an hour to go from empty to full.
