How to check battery health before you buy

State of Health (SoH) is the percentage of a battery's original capacity that remains. It's usually read with an OBD scan tool — LeafSpy for a Nissan Leaf, or a similar app for other models — not from the dashboard.

For a used EV or hybrid, 90% or higher is very good. 80–90% is normal for a car five or more years old. Below 80%, expect noticeably reduced range, and possibly a costly cell replacement down the line.

Ask the seller for a recent battery scan printout before agreeing to buy. The dashboard's estimated range isn't reliable on its own — it shifts with driving style, temperature, and terrain.