Owning and running a fleet of electric vehicles brings new paradigms and challenges to fleet operators. One major concern is the longevity and lifespan of an EV battery ⚡️ – considering we are used to replacing smartphone batteries after a few years of usage, it is understandable that people are expecting EV batteries to also be affected by capacity deterioration. This article is written to help you understand the technology behind an EV battery, the smart ways EV manufacturers engineer the battery to prolong its life, and what you can do to maximise the lifespan of EV batteries.
How comparable is EV battery lifespan to a smartphone battery?
All electric vehicles nowadays use the tried and tested lithium-ion battery technology, similar to the kind used in phones, laptops, and other rechargeable gadgets. Although the batteries share the same base technology, an EV battery is significantly larger and more durable.
Unlike batteries for mobile gadgets that seldom get hot (or too hot), an EV battery is often used in the open environment, exposing it to a wider envelope of operating condition. Some climates might be too cold, while others might be too hot. Or some might be both. EV manufacturers then implement numerous cooling or heating methods to ensure these batteries are within acceptable operating temperatures.
Similar to fossil-fuel engines that break if it gets too hot, coolant is used in EVs to cool down the large battery pack. However unlike engine coolant that needs replacing every few major services, coolant used in EV batteries is lifetime and not replaceable or serviceable. The coolant works in a closed system, goes through tubes, cooling plates, or other components that surround the cells and carry heat to another location, such as a radiator or a heat exchanger.
Do EVs use the same batteries?
There are two distinct types of lithium-ion battery used in EVs:
- Nickel-free LFP (lithium-iron phosphate) batteries
- Cheaper and safer with a long battery life.
- Often used by low-cost, long-range vehicles such as electric taxis and buses
- Higher degradation than NCM batteries
- High-nickel NCM (nickel, cobalt, manganese oxide) batteries
- More expensive, denser energy & higher power rating
- Higher capacity retention for the same number of charge cycle
- Often used by premium vehicles, such as the latest Porsche Taycan.
Some manufacturers like Tesla, uses both types for different models.
If you were to disassemble a Tesla Model S battery module, you would find a densely packed cylindrical batteries not too dissimilar to the standard AA and AAA batteries. These Tesla batteries are also called 18650 lithium-ion rechargeable battery, or “18650 cell”. Considered the most energy dense battery in the market currently, the battery allows for a travel distance of up to ~600km (400miles) on a single charge.
Moving forward as battery technology progresses, EV manufacturers are introducing new battery types with denser energy, allowing for either higher distance or smaller battery module in the car.
Does EV battery degrade over time?
Yes, technically all EV batteries degrade over time. As time goes by, the capacity for every charge decreases. Lower capacity = lower operating distance.
The extent of degradation differs depending on the technology used, exposure to high temperatures, type of use, charging profiles, driving character and so on.
You might not realise this yet, but the degradation in performance is not so different to a fossil-fuel vehicle. Fossil fuel vehicle tend to be less efficient as it accumulates distance, wear & tear. The engine consumes more fuel as the mechanical parts begin to falter. For a fossil fuel vehicle, it is expected for the operator to do preventive maintenance and scheduled services regularly for an optimum & reliable working condition.
Compare this to an EV where yes, the battery does degrade over time, but with a big caveat of not needing any major service at all during its lifetime. No engine oil to replace, no transmission oil, no oil filters, no coolant, no engine to rebuild after 10 years.
Transitioning to an all-EV fleet is not bad after all. 😄
Do I have to be worried about EV battery degradation?
In most cases, you don’t have to lose a sleep over it. In latest data shared by Tesla (August 2021), the battery degrades only by ~10% after ~350,000 kilometres (or 200,000 miles) of travel.
For context, it will take ~15 years to accumulate that travel distance for a regular private vehicle owner (at ~20,000 kilometres a year).
The battery module is likely to outlast the vehicle itself.
Unlike phones, or laptops with much smaller energy capacity, EV batteries are significantly denser and contains much higher capacity which limits the impact of degradation that occur over time.
With that being said, there is no harm in learning and will only serve you well to learn how to prolong EV battery life.
Tips to improve EV battery lifespan
1. Provide a shaded car park to prevent temperature extremes 🥵
Temperature extremes (too high or too low) is a battery’s greatest enemy. Parking in direct sunlight will expose the vehicle to high temperature. Depending on location & climate (equatorial for example), the ambient temperature might be too high and may require the automated temperature control system in the EV to kick in. This control system runs to get the temperature of the battery to be within limits.
While the system is meant to prevent exposure to high (or low) temp, the system also drains the battery… until there’s not enough power left if the car is continuously exposed to high temperature over a few days.
What happen when there is no juice left to power the cooling system? The vehicle will get baked. The battery will get ruined.
When managing a fleet of EVs, it is best to equip the EVs with a fleet management system that is designed specifically for electric vehicle operators. KATSANA EV Fleet platform streams real-time EV battery data to a unified cloud platform, providing you with actual real-time data of EV State-of-Charge.
2. Plug the car with a timed charger when it is parked for long period (a week or more)
Do not park EVs for long period having empty, near empty, or full charge. This will degrade its battery. If you are planning on a long holiday, or simply not using the car for a while, we recommend you to use a timed charger to manage the charging time.
3. Manage charging capacity to just 90% State-of-Charge
If you are using the car for daily travel, develop a habit to charge it to just 90% of the capacity. This is generally healthier for the battery = less strain than accommodating a full capacity. Most EVs often have an option to cut off charging when it reaches a certain State-of-Charge. Try to keep your battery between 25-75% SoC most of the time.
4. Charge to 100% only when you plan for long drives 🔋
While we recommend charging to 90% for daily drives, there are times when you need to travel far. Charge to 100% only when you absolutely need the operating distance, for example highway interstate cruise. For the other days, 90% charge is sufficient.
5. Never allow EV battery to be completely empty or at very low level
EV battery does not like all the extremes (too low or too high charge, too slow or too fast charge, too low or too high temperatures). In this case, while EVs already have built-in battery management system that prevent a complete drain of power, it is still advisable to never allow its State-of-Charge to be effectively inoperable (empty) or lower than 10%. Start charging the car when it reaches 15% SoC to preserve the capacity of the battery.
It sure is easy to ensure the EV is charged within optimum State-of-Charge (between 15-90%) if you run a single EV. However it proved to be an undertaking once you start managing a fleet of electric vehicles. For one, how do you keep track of the battery State-of-Charge across the entire fleet?
This is where Katsana EV Fleet platform comes in to save the day. KATSANA collects real-time EV data and tabulate them on a unified fleet operations platform for EV operators.
6. Reduce fast charging events
Fast chargers are a great convenience as it allows charging from 10% SoC to 80% in just 20-30 minutes. However as you guess, this puts a great strain to the battery due to high current and make the battery wanes faster. Use fast chargers when you need to charge fast, for example on highways. A standard charger is always advisable if you are not pressed for time.
For context, frequent use of fast EV chargers will degrade the battery by roughly 10% after 8 years, compared to consistent use of standard chargers.
7. Do not charge in cold weather (or from a completely cold state) 🥶
Parking: If you live in cold climates, it is advisable to store the car away from the elements. Shades, garages or underground parking are good options. The low temperature can potentially damage the battery, and known to lower the operating distance in actual operation.
Charging: When charging the vehicle, do not charge when the car is in a complete cold state. Warm up the car first. Drive it around. Get the battery up to optimum temperature. Some EVs will inform you that the battery is within good temperature range for charging (too hot or too cold). Charge when the car and the battery have warmed up.
8. Reduce high speed driving & use of launch control (bonus tips)
While EVs on overall are faster than fossil-fuel cars, continuous use of launch control (for century-sprint) purposes will weaken the battery. Launch control and high-speed driving (beyond 160km/h) put a big strain to the battery. These demanding tasks generate higher current than usual, and heats up the battery fast.
Discharging events (in this case, launch control and high-speed driving) generates heat. The more rapid you discharge a battery, the more heat it generates. If there is a large internal temperature difference in the cells, it can lead to different charge and discharge rate and will deteriorate the battery pack performance.
Tesla in the past, was well-known for limiting the number of launches that you can do.
“Like other automakers, our performance vehicles continually monitor the condition of various components and may employ limiting strategies to reduce fatigue on the powertrain.”
Managing a fleet of EVs should not be a daunting task.
KATSANA EV Fleet operation platform is designed to help fleet operators like you ease the transition into clean mobility. By providing fleet operators with real-time EV data such as the State-of-Charge and Charging status across EVs of various makes and models, we hope this can hasten net zero carbon emission for a cleaner future.
Be in touch with KATSANA team to empower your EV fleet with real-time data.
Take control of your EVs.
Written by Fuqaha, CEO of KATSANA Holdings. Connect with me on LinkedIn.