...and compare it to several other city models.
The Renault ZOE is currently the best-selling electric car in Europe with a cumulative result already far above 250,000 (despite no significant volume recorded outside of Europe).
Here we will try to analyze DC fast charging of this important model, using test results released by Fastned, and then compare it to several other small, city cars to better understand what this type of EV is capable of.
The ZOE is of course not envisioned for long-distance travel, nor for very often use of DC fast charging (it has a 22 kW three-phase on-board charger). The first generations of ZOE were not even equipped with the DC charging option. Since the ZOE Z.E. 50 came out, many potential customers may wonder whether it's worth it to buy the option of DC fast charging (often at around €1,000 or so).
Charging power vs state-of-charge (SOC)
According to the test results, the Z.E. 50 (equipped with a 55 kWh battery) can recharge at up to 46 kW. It's not much, but the simple air cooling of the battery probably is too weak to accept higher power. That's a major difference compared to 100 kW noted by the Peugeot e-208.
The charging curve is pretty much plain, with peak output available at up to 30% SOC.
Average charging power vs state-of-charge (SOC)
The average power when charging from 20% to 80% SOC is 36 kW.
Because of the 22 kW on-board charger (three-phase), there is basically no point in searching for/using DC chargers at SOC above 60%, because the advantage over 22 kW AC charging will be low (a few kW on average) at a much higher cost (usually).
Charging rate vs state-of-charge (SOC)
The peak C-rate* - charging power in relation to the total battery capacity of 55 kWh - is about 0.83C.
We knew it would be low, but it turns out lower than in the case of the Volkswagen e-up! (2nd model evolution), Škoda CITIGOe iV and SEAT Mii Electric, which is a surprise.
*C-rate tells us how the charging power relates to the battery pack capacity. For example: 1C is 1-hour charging power (current), when the power value in kW is equal to the battery pack capacity in kWh. 2C would be enough to recharge in half an hour.
Range replenishing speed vs state-of-charge (SOC)
Finally, the range replenishing speed. Taking into consideration WLTP range of 395 km (245 miles) and available battery capacity of 52 kWh, we can assume energy consumption of 132 Wh/km (212 Wh/mile).
The effective speed of range replenishing in km/minute (miles/minute) would be then as follows:
The average speed of range replenishing when charging from 20% to 80% SOC is 4.6 km/minute (2.8 miles/minute).
There is really nothing fast in the ZOE DC charging and we believe that only in some specific cases, the purchase of the relatively expensive option would be justified. For the majority, the 22 kW on-board charging system in the ZOE is enough and there is no stimulus to upgrade. It could be different if the DC charging speed was faster.
Comparisons with other EVs
Let's take a look at how the ZOE Z.E. 50 stands against its major competitor from France - Peugeot e-208 (the results applies also to DS 3 Crossback E-Tense, Opel Corsa-e/Vauxhall Corsa-e, Peugeot e-2008, Citroën e-C4 and Opel Mokka-e/Vauxhall Mokka-e), as well as a few other small city cars: BMW i3 (42 kWh), MINI Cooper SE and Volkswagen e-up! (2nd model evolution), Škoda CITIGOe iV and SEAT Mii Electric.
Comparison of charging power
The charging power curve reveals immediately the winner - Peugeot e-208 - offers the highest levels (up to 100 kW), although it falls quickly in the end.
The rest of the group sits under 50 kW. Both the BMW i3 and MINI Cooper SE sustain a stable level over a wide window of SOC thanks to the liquid-cooled battery pack. The ZOE and VW's triplets are left behind, but those are also more mainstream, less expensive models.
Comparison of charging rate
The peak C-rate comparison is quite interesting, as it shows ZOE on the bottom with the lowest charging output per battery capacity - below VW's triplets
On the other hand, the MINI Cooper SE has a far more aggressive charging curve than the BMW i3. The smaller pack of the MINI withstands similar charging power as the BMW.
The Peugeot e-208 starts very strong, at 2C, but after 50% of SOC, it's falling behind BMW/MINI.
Comparison of range replenishing speed
The last comparison is one of the most important because it shows us several EVs and their effective speed of replenishing the WLTP range.
The Peugeot e-208 really stands out among subcompact electric cars. Both, BMW i3 and MINI Cooper SE are stable above 5-6 km/min, while ZOE Z.E. 50 barely beats the triplets.
The average range replenishing speed 20-80% SOC :
- Peugeot e-208: 7.6 km/min (4.7 miles/min)
- BMW i3 (42 kWh): 6.4 km/min (4.0 miles/min)
- MINI Cooper SE: 6.1 km/min (3.8 miles/min)
- Renault ZOE Z.E. 50: 4.6 km/min (2.8 miles/min)
- VW's triplets: 4.0 km/min (2.5 miles/min)
* Some values on the charts are estimated from the data source.
** Temperature of the battery cells might highly negatively affect charging capabilities. We don't have data about temperatures of the battery at the beginning and during the charging process. In cold or hot weather, as well as after driving very dynamically, charging power might be significantly lower than shown on the charts (in extreme cases charging might be impossible until the battery temperature will not return to an acceptable level).