From what I’ve seen in long-term EV ownership discussions, battery replacement isn’t something that happens on a fixed schedule. Most packs tend to be serviceable for many years, and what usually drives attention to replacement is gradual capacity loss rather than a sudden failure. In real-world use, a lot of owners only start seriously thinking about
ev battery replacement when the usable range drops enough to affect daily driving patterns, not because the battery “expires” at a certain age.
It also seems that how the car is used matters more than time alone; things like frequent fast charging, high heat exposure, and deep discharge cycles tend to have more impact on degradation than just mileage. In practice, many packs are still holding up reasonably well past the 8–12 year mark, even if they’re not at original capacity.
You are going to have to do better than that to demonstrate that you are a human non spammer.
Don't worry, they may be AI but I'll try my best.
What warrenautolab said matches my expectation from NMC/LFP chemistry.
First, cycle life:
NMC cells are generally expected to last >1000 cycles to 80% capacity. This benchmark is not standardized, but usually involves a charge rate of 0.2C or 0.5C, and a discharge rate between 0.2C and 1C. LFP cells are usually tested under similar conditions, and can last more than twice as long in cycles. Note, basic practice such as avoiding ever fully discharging or charging the battery can similarly double the cycle life or more. Rule of thumb being 10-90% will give you 2x the cycle life, and 20-80% 3x.
Second, calendar aging:
This one is more complicated, depends on the particular cell design and chemistry more, and also is likely the biggest factor in EVs, as most of the life of an EV battery pack is spent sitting.
As shown in this figure (
Redirecting.), when kept stored at 80% charged and at 25 Celsius, for 2 years, their tests showed approximately 6% loss of capacity. The cell they were testing was the LG M50T, which is honestly not a particularly amazing cell, so I will carry on my calculations with this number. Note, it is better to leave a battery sitting when at a lower state of charge, but I expect most EVs spend a lot of time fairly close to full charge as a matter of expediency, hence 80% SoC as the focus.
Counting cycles is more complicated than just how many times a cell/battery has been fully charged and discharged- This is why cycle life is honestly kind of a mess. Mostly, cycle life testing is for 100% DoD (depth of discharge), where the cell is charged from 0% to 100% and then discharged, given a short break, and then repeated. For modern cells, this is commonly 2.5V to 4.2V
However, it is common practice when building an ebike battery pack to count cycles by 80% of full capacity, and I'm not exactly sure why (I would expected 90%, if you were averaging between 100% capacity when new and 80% capacity when replaced...).
Regardless, assuming no fast charging, and road legal driving, EV batteries should not be subjected to conditions worse than standard test practices. Discharging the whole battery pack in 5 hours of continuous driving would be .2C discharge rate, for example. Most cells can handle 1C discharge rate without significantly worse cycle life, at least cells that I would expect to find in an EV. Level 2 charging generally maxes out around 20kW if I recall correctly, which for a 100kWh battery pack would be .2C charge rate. Assuming that most EV battery packs have adequate cooling and heating systems, cold temperatures may decrease range and waste energy, but likely keep the cells themselves within the acceptable range.
With those assumptions in mind, a quick calculation can be done for the expected miles an EV battery pack can deliver before it reaches the 80% capacity threshold: I will use the Ioniq 5 as an example.
The first gen Ioniq 5 RWD, standard range, has a 58kWh battery pack, and a claimed range of 220 miles (EPA), which I will round down to 200 miles because EPA range is fake.
A basic approximation would be >1000 cycles * 0.9 (averaging range loss) * 200 miles = >180,000 miles until 80% capacity.
Thus, from a simple cycle life perspective, even a intermediate range battery pack should last you ~200,000 miles without fast charging.
Assuming 0 miles are driven and an EV is merely kept at 80% state of charge until its range drops to 80%, based off of the figure above, you can expect about 7-8 years. Note, if you live in a hot location and the battery spend a lot of time cooking at >45C, this could be actually a pretty big hit to calendar life. According to the same paper above, at 45C the cells lost 10% capacity at 500 days, vs 6% in 750 days. When driving at least, thermal management will prevent this under normal use.
TL;DR I would start being concerned about the battery pack at 200,000 miles, or 8 years of age, as I would expect it might start cutting into the maximum range significantly. There's definitely more consideration on an individual basis, so this is just an explanation for a ballpark estimate/rule of thumb. Considering common use cases being mostly commutes and level 1 charging, some basic precautions such as keeping between 20% and 80% charged, would likely extend the cycle life by a factor of 2 or 3, making calendar aging actually much more relevant than cycle life (at 500,000 miles, most cars start falling apart anyways...).
Hopefully that was more informative than AI
