Battery life: A key component of your electric vehicle's TCO

As the single most expensive components in an electric vehicle’s driveline, long battery life is a crucial factor in any Total Cost of Ownership (TCO) analysis. Fortunately, there are measures that you can take to ensure a battery maintains its capacity for longer.?

Batteries inevitably lose capacity as result of a declining state of health over time and eventually will need to be replaced. Along with the high up-front cost (which is also due to the battery), this is one of the most significant contributors to the total cost of ownership of an electric vehicle. Quite simply, the longer a battery can last and provide required performance, the lower the TCO.

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“At least half of the cost of an off-road electric driveline is the battery, and it can be as high as 80 per cent in case of large battery installation,” says Zeyd Okutan, Volvo Penta’s Product Manager.

Factors that determine battery life in an electric vehicle

The power capability of the battery and the duty cycle of the vehicle are two important factors for defining the choice for application. Applications that require high charge and discharge power will require the right chemistry of batteries and necessary amount of energy content. Essentially battery lifetime is defined by the number of cycles or complete energy through lifetime:?the more a battery is charged and discharged, the faster it will lose its capacity. As with a diesel vehicle, the higher the loads on the vehicle, the more energy it will require. Power usage of the vehicle will have direct impact on the battery lifetime. Then there are other factors like chosen state of charge window, and environmental factors as humidity, temperatures and vibrations. For this reason, it’s important to specify the right battery and driveline according to its intended use.

“When it comes to electric drivelines, the battery’s chemistry, size and even the shape are already decided in the beginning of the design phase, so that it is the best fit for its specific application,” says Zeyd “A battery installed in a driveline designed to last for eight years of operation in one application might only last four in another. For this reason, you cannot take a driveline designed for one application, and simply use it in another and expect the same service life.”

Therefore, the most important measure is to understand the vehicle’s usage pattern and only use it for its intended purpose.

Right battery for the right job

As with diesel, specifying an electric driveline according to its application will maximize efficiency and minimize downtime. A battery that is larger than what is required will increase costs and add unnecessary weight to the vehicle. A battery that is too small will need to be charged more often and stressed with high power demands which will not only increase downtime but will also cause the battery to wear out quicker.

However, it’s important to stress that battery technologies are developing rapidly. The power density and energy density are continuously improving, while the general trend is that the cost per kwh is falling. Both factors will have a profound impact on the total cost of ownership.

There are also increasing opportunities to reuse old batteries for other purposes, such as power storage, home use or low power demanding applications. This can further reduce the TCO of an electric vehicle, as well as improve its environmental impact.

“Admittedly the price of batteries is decreasing slower than predicted due to soaring commodity prices, raw material shortages and supply chain bottlenecks, but the improvements being made in battery technologies and increased electrification in off highway segments will ensure they will continue to become more cost-effective,” says Zeyd.

Read more

• Looking beyond the purchase price
• Calculating total cost of ownership and profitability
• The hidden costs of fuel