Used EV Battery Health: A Buyer's Guide

The battery is the most expensive component in any electric car, so understanding its health is the most important part of buying used. This guide explains what to check and why it matters.

What is State of Health (SoH)?

State of Health is the battery's current capacity compared to when it was new, expressed as a percentage. A car at 100% SoH has its full original range; at 80% it has lost a fifth of its capacity.

Most EVs lose 1–2% per year with normal use, so some degradation is completely normal and expected.

How to check it

• Ask the seller for a battery health report — many EVs can generate one via the dashboard or a diagnostic app.
• Compare the car's current range estimate when fully charged against the original spec.
• Be cautious of cars that have spent their life on rapid chargers, as heavy DC fast charging can accelerate wear.

What's a good number?

For a car that's 3–5 years old, 90%+ SoH is excellent and 85%+ is perfectly healthy. Below 80%, you should expect a noticeably reduced range and factor that into the price.

Every listing on UsedEVs.ie shows battery health up front, so you can compare with confidence.