The key to Battery longevity is usage and charging pattern. Higher mileage does not indicate the state of the battery, indeed a lower mileage vehicle with a poor charging regime can offer higher value. This is one of several situations where unlearning of ICE (Internal Combustion Engine) thinking is required.
Nissan Leaf example
Leafs are not know for having a good Battery Management System, however despite that this example shows minimal battery degradation.
Batteries typically degrade at around one percent per year although can be less with careful charging. Without a BMS it would be nearer 2% per year.
Battery Management System
Battery Management Systems are designed to reduce the impact of charging on the battery.
To understand any particular battery you will need to obtain the State of Health (SOH) figure.
Car batteries can be expected to last longer than the rest of the car. For some years an 8 year / 100,000 thousand mile battery warranty has been standard from most manufacturers, previously it was 5 years / 60,000 miles. [Battery warranty]
Limited battery lifespan is one of the most common myths about electric cars. Not only do automakers like Tesla and Volkswagen expect batteries to last the life of a vehicle, but some expect them to last longer, and have proposed so-called “second-life” uses of batteries as stationary power sources.
The first tip is to try to keep the battery from discharging to low levels, specifically below 20% capacity. That goes hand in hand with Hyundai’s second tip, which is to charge frequently in order to prevent the battery from draining too much.
Hyundai recommends charging every two to three days. This also ensures the car is prepared ahead of time for long trips, the automaker noted.
While driving, it’s best to avoid heavy acceleration, which drains the battery more quickly, according to Hyundai. Maintaining a consistent speed, rather than abruptly accelerating or braking, is the most efficient way to drive.
Nissan Leaf batteries are passively air-cooled, and hence lose capacity more quickly than batteries from Tesla, GM, and others that are actively liquid-cooled.
But long before recycling, electric-car batteries will have second and third lives well beyond their automotive use. Small businesses are forming to rack them for energy storage in buildings, etc. Some carmakers are even going into that business themselves.
The value of a battery that cost $5,000 to $10,000 new does not suddenly fall to zero, so people won’t want to toss them. They’re too valuable, and could live on for as long as a few decades.
Remember that manufacturers only design cars for lives of 10 to 12 years and 100,000 to 150,000 miles to start with, though Toyotas and a few other brands often last far longer.
Thus far, data shows Tesla batteries have only lost about 10 percent of their energy capacity after 100,000 miles.