Weltmeister EX5 impresses with low battery capacity degradation
Launched last year in China the Weltmeister EX5 is currently listed with a starting price of 139.800 yuan (17.561 euros) after subsidies. This is a very appealing electric car sized between the Kia e-Niro and the Tesla Model Y.
Let’s see some of its specs:
- Wheelbase: 2.703 mm
- Length: 4.585 mm
- Width: 1.835 mm
- Height: 1.672 mm
- Motor: 160 kW and 315 Nm of torque
- Acceleration: 0-100 km/h in 8,3 seconds
- On-board charger: 6,6 kW
- DC fast charging: 30 to 80 % in 30 minutes at 120 kW chargers
- Battery capacity: 69 kWh with lifetime warranty
- Battery weight: 432 kg
- Battery energy density: 160 Wh/kg
- Range (NEDC): 520 km (323 miles)
Considering that range in WLTP is roughly 3/4 of NEDC, in a more realistic test cycle the range would be around 390 km (242 miles). Not bad at all considering the price.
Now the automaker has some battery data to share with us.
To help alleviate concerns surrounding one important consideration among car buyers, the degradation of EV batteries over time, WM Motor has long promoted the benefits of high-quality thermal management and battery management systems (BMS) in EV’s to maintain the long-term stability of a battery’s capacity. Data from one of WM Motor’s EX5 models purchased in January 2019 has provided an insight into the car’s long-term battery degradation rate. The driver of this EX5 undertakes lengthy commutes between Wenzhou, Ningbo and Hangzhou, among other cities, and has averaged approximately 500km daily and accumulated over 200,000km of driving since purchasing the vehicle last year. Having been brought in for a regular check-up this week, the battery was found to have degraded by only 2.85% from its original capacity.
Battery data after 200.000 km (124.274 miles):
- Charged 90 % of the times at DC fast chargers
- Charged over 1.500 times (partial charges)
- Battery capacity only dropped by 2,85 %
There are multiple of factors that influence battery degradation. One such factor is the method used to charge the battery, with the general rule being that the faster a battery is charged on average, the faster that battery will degrade over its lifetime. This EX5’s capacity retention rate of 2.85% after 200,000kms would be extremely high compared to the industry standard even if the vehicle was most often charged at a slow, alternative current (AC) home charger. However, due to the vehicle owner’s long-distance travel requirements, the vehicle was charged using public fast direct current (DC) chargers approximately 90% of the time, which makes a 2.85% degradation rate even more noteworthy. At the time of testing, the vehicle had been put on charge over 1500 times.
WM Motor contacted me to inform that these battery cells in the EX5 are NCM 811. I’ll update with more information if I get it.
Anyway, since the arrival of modern NCM 523 and NCM 622 batteries in late 2016 we can have high mileage electric cars that lose very little battery capacity and range. They just need a decent TMS (Thermal Management System) and to have their batteries cycled at lower SOC (State-of-Charge) with a good BMS (Battery Management System).
However, I recognize that all this recent marketing around million-mile batteries is very important to change people’s perception about electric cars. We can’t forget that some first generation electric cars gave really bad reputation to EV batteries with their extremely high degradation rates.
More electric cars like this one that has a lifetime battery warranty or the Lexus UX 300e that offers a 10-year or 1 million km warranty on its battery might be needed to provide peace of mind to most potential EV customers.