The average EV battery loses roughly 1.8% of its capacity per year, according to Geotab's 2024 analysis of about 10,000 fleet vehicles. That is the headline. The useful part is that the spread is wide: the same model, the same age, can sit anywhere from 1% a year to 4% depending on chemistry, cooling, climate and how it was charged.
The curve is not a straight line
Degradation is fastest in the first year or two — an early drop of a few percent as the pack settles — then slows to a long, shallow decline, then may steepen again late in life. So a one-year-old car reading 96% is normal, and a five-year-old car reading 92% is also normal. Age alone does not tell you where a car should be.
A rough table of "normal"
| Age | Typical range for a well-managed pack | Worth a question |
|---|---|---|
| 1 year | 96–99% | Below 94% |
| 3 years | 92–97% | Below 90% |
| 5 years | 88–95% | Below 86% |
| 8 years | 82–92% | Below 80% |
These are expectations for liquid-cooled packs in private use, not guarantees. An air-cooled pack in a hot garage will sit below them; a lithium-iron-phosphate pack charged sensibly may sit above them.
What moves a car off the average
Chemistry. LFP packs degrade more slowly and tolerate full charging. Nickel-based packs (NMC, NCA) are more energy-dense and more sensitive to being held at 100%.
Cooling. Liquid-cooled packs hold temperature; air-cooled packs do not, and heat is the main accelerator of calendar ageing.
Charging habits. Time spent at 100% and time spent on DC fast chargers both age a nickel pack faster than home charging to 80%.
Climate. A car parked in the sun in Western Sydney all summer ages faster than the same car in a Blue Mountains garage.
Use. High kilometres add cycle ageing; low kilometres do not stop calendar ageing. A car that sat unused at 100% for a year did not have an easy year.
Reading a State of Health figure properly
The number on its own is half the story. The other half is cell-group voltage spread — whether the cells are ageing together or one group is falling behind. A car at 90% with tight cell balance is a healthy car. A car at 90% with one group drifting is a car whose number will fall faster than the average from here.
That is why a test reports both, and why a dashboard range estimate — which reports neither — is not a substitute.
Q&A
Is 2% a year bad? No. It is average. Over eight years that is about 85%.
Is 5% a year bad? It is above average and worth understanding why — chemistry, cooling, charging history — before you pay full price.
Does degradation speed up? It can, late in life or when one cell group fails. Cell balance is the early warning.
How long do EV batteries last · What is a good State of Health · Book a test — $249
Average degradation rate from Geotab's 2024 analysis. The age table is our own guidance based on published fleet patterns, not a manufacturer specification. Verified 15 September 2026.