Buying guide
Used EV battery health: how to check it before you buy in Iceland
State-of-health (SoH) is the single most important number on a used EV. Here's exactly how to read it on Tesla, Hyundai/Kia, VW Group, and BYD.
Why this matters more than anything else on a used EV
The battery is 35–50% of the car's value. Everything else is replaceable for known money. A degraded battery turns a "good deal" into a money pit.
What State of Health (SoH) actually means
SoH is the ratio of current usable capacity to original usable capacity.
- New EV: 99–100% SoH
- 3-year-old EV (60–80k km): typically 92–96%
- 5-year-old EV (100–140k km): typically 86–92%
- Heavily-used taxi/Uber EV at 5 years: 75–85%
What's normal vs what's a warning
| SoH at car age | Status |
|---|---|
| 3yr / >94% | Excellent |
| 3yr / 90–94% | Normal |
| 3yr / 85–89% | Below average — investigate |
| 3yr / <85% | Probable issue, big price lever or walk away |
| 5yr / >89% | Excellent |
| 5yr / 85–88% | Normal |
| 5yr / 80–84% | Below average |
| 5yr / <80% | Warranty claim territory on many brands |
How to get a battery health report in Iceland
- Authorised dealer scan — 15–25k ISK; often free if seriously considering buying.
- Independent EV specialist — Rafbílar.is, Elding. 20–30k ISK.
- Aviloo / Volytica third-party certificate — Europe-wide gold standard. ~35k ISK.
Avoid the car's own app self-reported SoH — it can be off by ±4%.
Warranty status — check this BEFORE the SoH number
Most EVs sold in Iceland after 2020 have an 8 year / 160,000 km battery warranty with a 70% minimum SoH guarantee. Some brands extend to 10 years.
What kills batteries fast in Iceland
- Repeated 100% charging on long trips
- Frequent DC fast charging in summer heat
- Letting the car sit at 100% in summer for days (common with rental fleet cars)
- Letting the car sit at 0–10% in winter cold
Price impact of SoH on resale
Every 5 percentage points of SoH below "expected for age" is worth roughly 150–250k ISK off ask on a typical 5–7M ISK car.
Bottom line action list
- Confirm warranty terms in writing
- Insist on an SoH test, or pay for one yourself
- Compare to age-appropriate norms
- Use any gap as a price lever, or walk
- Save the report — you'll want it when you sell