The charging curve: 350 kW, then a steep slide
The peak number is the least interesting figure in the whole session. The CLA pulled around 350 kW within the first minute — Mercedes itself quotes up to 320 kW for this 800-volt architecture, so the logger was reading a little more than the brochure — and then the curve behaved like every good fast-charging curve should: it fell away smoothly rather than collapsing. Below 300 kW by roughly 10% state of charge, mid-200s at 20%, about 160 kW at 30%.
What that produces at the plug is what a family on a holiday drive actually experiences:
- 10% at 2 minutes, 25% at roughly 5.5 minutes
- Closing in on 40% after 10 minutes
- 50% after 15 minutes
- 75% after 25 minutes — and still pulling more than 150 kW
Nobody drives a long trip from 0% to 100%, which is why the honest benchmark is the 10–80% window. Mercedes claims 22 minutes; Moloughney measured 26. Four minutes off the marketing figure for a real DC session is respectable, not embarrassing. A full 0–100% run took 52 minutes on Electrify America and 56 minutes on Ionna — the last 20% is always the expensive part in time, wherever you charge.
Preconditioning made no difference — in summer
The interesting wrinkle: one session used battery preconditioning, one didn't. The non-preconditioned run was a hair faster, staying about 1% ahead throughout. That is not a case against preconditioning — it is a case for reading the ambient temperature. Moloughney charged in stable summer warmth, with a pack already at operating temperature after a highway stint. On a Czech January morning at −3 °C, with a cold-soaked pack, the same car would tell a very different story. If you buy an 800-volt EV, program the charger as a navigation destination so the car conditions the battery before you arrive. Our real-world range calculator (built on Bjørn Nyland's measured data) is the tool to check how much winter costs you in kilometres — we don't have CLA data in it yet, and I would rather say that than invent a number.
The number that actually matters: kilometres per minute
Take the tested highway range of 620 km. Charging from 10% to 80% adds 70% of that — about 434 km — in 26 minutes. That is 16.7 km of highway range per minute. In the first 15 minutes, 0–50% adds 310 km, or 20.7 km per minute. For context, BMW quotes up to 400 kW and a 21-minute 10–80% for the new iX3, and the refreshed Tesla Model 3 Long Range still sits around 250 kW peak. The CLA is not the fastest-charging EV on sale, but it belongs in the top handful of cars where range and charging speed work together — and it pairs that with software: the CLA is the first Mercedes on MB.OS, while BMW is still rolling out features like the unified 3D navigation and driver-assist view arriving in the iX3 this October.
What it costs in euros: about €10 per 100 km on DC
Here is my own calculation, with the assumptions stated. With roughly 85 kWh usable and 620 km of tested highway range, the car averaged about 13.7 kWh/100 km at 70 mph. Refilling 434 km therefore needs around 60 kWh at the wheels, plus 5–8% charging losses on a DC charger — call it 63 kWh. At €0.69/kWh, a typical European public DC price, that is €43, or about €10 per 100 km. The same distance on a home AC tariff at €0.25/kWh costs roughly €3.50 per 100 km. A 6.5 l/100 km petrol car at €1.55/l burns €10.10 per 100 km.
The conclusion is not that the CLA is expensive to run. It is that highway fast charging in Europe is priced at petrol level. Run the numbers for your own tariff in our charging cost calculator, and check our database of 483 European charging locations (or the cheapest sites list) before you plan a route — the spread between hubs is bigger than the spread between cars.
Europe versus the US test
The CLA is a European car first: WLTP figures for the CLA 250+ stretch up to 792 km, and Mercedes lists it in Germany from roughly €55,500, with the 350 4Matic we are discussing a few thousand euros higher — before any local incentive. That is a different price bracket from the $49,400 US starting figure, and it is the reason a corporate buyer should compare it with the iX3 and the Model 3 on lease rate, not sticker. Chemically, cheaper entry versions in this class increasingly lean on LFP cells — a chemistry now at a record 85.6% of Chinese battery output, as we covered in August's battery market data — so expect the price ladder below the CLA to keep moving.
Practical takeaway: if you regularly drive 500+ km in a day, the CLA's combination of ~620 km of real highway range and a 26-minute 10–80% stop means roughly two charging stops per 1,000 km. That is a genuinely usable long-distance EV. Just do the tariff homework first — the car is quick; the invoice is quicker.
Does the CLA need preconditioning on a European winter trip?
In summer warmth it made no measurable difference in this test. At near-freezing ambient temperatures a cold pack is the single biggest limiter of DC power on an 800-volt car, so always set the charger as a navigation destination and let the car heat the battery on the way. Expect a slower ramp and longer stop than the 26 minutes measured here.
Is an 800-volt car worth it if most European chargers deliver 150–250 kW?
Yes, but not for the peak figure. On a 150 kW stall the CLA is limited by the charger, not the car — 60 kWh still takes roughly 24–30 minutes. The 800-volt architecture pays off when you find a 350–400 kW hub, where the car stops being the bottleneck. Check which hubs are on your regular route before paying a premium for charging hardware you may rarely use at full rate.
Source: https://insideevs.com/news/808559/mercedes-cla-among-best-chargers/
