The rules of thumb by age
Every battery wears, so never expect exactly 100% from a used car. As a rough guide — the real condition depends heavily on charging behaviour and climate:
| Age of the car | Expectation | Attention needed from |
|---|---|---|
| 0 – 2 years | 97 – 100% | below ± 95% |
| 3 – 5 years | 92 – 97% | below ± 90% |
| 6 – 8 years | 87 – 94% | below ± 85% |
| 9 years and older | 80 – 90% | below ± 75% |
What does SOH mean for the range?
Very directly: a car that did 400 km when new still does about 340 km at 85% SOH (400 × 0.85). In winter the normal cold reduction comes on top. If you drive long trips daily, you feel every percent; if you mostly drive in town, you hardly notice it — but the value of the car does change.
What does SOH mean for the price?
The battery is roughly a third of the value of an electric car. A few percent of extra wear therefore justifies a serious price discussion — especially around warranty and trade-in moments. With a certificate in hand, that discussion is no longer a yes-no game: it is in black and white, and the buyer can verify it via the QR code.
Note: dashboard percentage ≠ SOH
How to use this when buying
- Always ask for a recent SOH measurement — or have one done on the spot (a few minutes)
- Put the number next to the age of the car (table above)
- Also look at the cell balance: a nice SOH number with a large cell difference is still a warning
- Below expectation? Negotiate — or walk away. There are plenty of cars with a healthy battery
Want to know the real SOH?
One measurement, a few minutes, black-and-white results with QR authenticity check.
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