How to check the battery’s condition?

Checking the battery’s condition takes a few seconds and saves you a surprise in the car park. A simple voltage meter is enough, and for a deeper diagnosis — a load tester.

Measuring the resting voltage

Voltage is measured with the engine off, ideally after a few hours’ standing. A healthy, charged battery shows about 12.6 V. Values below 12.4 V mean a partial discharge, and below 12 V — a heavily discharged or worn battery.

• ~12.6 V and above — charged, healthy
• ~12.4 V — partially discharged, worth recharging
• below 12.0 V — heavily discharged or worn
• During starting the voltage shouldn’t drop drastically

Charging voltage from the alternator

After starting the engine, the voltage at the terminals should rise to about 13.8–14.4 V — a sign the alternator is charging the battery. Too low a value can point to a charging problem rather than the battery itself.

The load test

Resting voltage alone doesn’t tell the whole story. A worn battery can show correct voltage yet still collapse under the starter’s load. That’s why a reliable assessment comes only from a load test with a special tester.

Good resting voltage is no guarantee — only a test under load shows whether the battery really holds.

When replacing the battery with call-out we check its condition and the charging voltage, to rule out an alternator problem.