Renault’s small ZOE has been one of the most popular electric cars in Europe for years. According to the French manufacturer, more than 99% of all batteries used in the ZOE since its market launch in 2013 are still fully functional and have at least 70% capacity at the time of vehicle purchase.
This applies to all types of batteries, from the 22 kWh of the first years of production to the current 52 kWh.
It is feared that the batteries of electric cars will lose a lot of power at first, or even fail completely. So far, this hasn’t happened on a large scale, but some remain concerned about long-term sustainability. For him, Renault offers an eight-year or 160,000-kilometre warranty on batteries purchased for the ZOE. The French manufacturer has also guarantees a minimum capacity of 70% of the value of the vehicle at the time of purchase during this period or throughout the circuit.
Battery chemistry loses storage capacity over time. Beyond Renault’s warranty, the company says this has happened very rarely.
Less than 1% of all ZOE batteries put into circulation in Germany fell below this threshold and had to be replaced. This also applies to vehicles whose battery warranty has already expired. Concerns about declining performance of energy storage units are unfounded.
In the current ZOE, only lithium-ion batteries with high energy and power density are used. An intelligent battery management system measures the temperature and voltage of each individual cell in the state-of-the-art energy storage units, ensuring they don’t overheat or cool during operation and lose their performance. This protects cell chemistry, creating the foundation for long, trouble-free battery life.
Replacement or repair.
In the event of a battery failure, Renault differentiates whether the battery was purchased with the vehicle or rented separately. The latter was an offer available until November 2020, where the rental price was based on running time and mileage. If it is a rental battery, the customer receives a used, “but perfectly functional” battery, the condition of which meets the conditions of the guarantee.
If it pays off, the old energy storage unit is repaired and put back into the cycle, either again as a storage unit for an electric vehicle or for stationary applications.
It is different for purchased batteries: In this case, Renault always sends the battery for repair and then reinstalls it in the vehicle. A battery is only replaced if the repair costs exceed the value of the battery.
According to Renault, often batteries can be restored to normal, fault-free condition by replacing individual modules. This is much cheaper than replacing the entire battery and is therefore particularly important for customers whose electric vehicles have already exceeded the battery warranty period. For this, only new modules are used. ZOE’s current battery consists of twelve units of this type, each containing 16 elementary cells and housed in a single casing.
Renault workshops can determine the condition of the traction batteries with a diagnostic tool.
In future, this will also be possible for owners of electric vehicles themselves via the My Renault app.
Renault explains that currently develops a digital battery certificate for Renault and Dacia electric cars on the remaining energy capacity of the traction battery. This should make it easier to calculate the residual value of vehicles, help facilitate resale and give the buyer certainty about the “state of health” (SoH) of their battery. The certificate data is read from the vehicle’s battery management system. The information about the ratio between the original capacity and the current capacity of the battery is output as a percentage.