CCA Testing: How Cold Cranking Amps Are Measured

Battery Testing Methods · Last reviewed 2026-09-15

Direct answer: A true CCA test chills a fully-charged battery to the standard's temperature, then discharges it at a constant current for a set time while watching that the voltage stays above a cut-off. Under SAE J537 that is −18°C for 30 seconds at or above 7.2 V. The CCA rating is the current the battery can sustain under those conditions.

The cold-chamber test (SAE J537)

Fully charge the battery, then chill it to −18°C (0°F) and hold it there.
Discharge at a constant current for 30 seconds.
The battery passes if its voltage stays at or above 7.2 V (1.2 V per cell) for the full 30 seconds.
The rating is the current at which it just passes.

Why the number depends on the standard

Standard	Temperature	Cut-off / method
JIS D5301	−15°C	reference (warmer → higher number)
SAE J537	−18°C (0°F)	30 s, ≥7.2V
EN 50342	−18°C	10 s to 7.5V
DIN 43539	−18°C	30 s to 9.0V

A warmer test or a lower cut-off prints a higher number for the same battery. A JIS value (tested at −15°C) reads higher than an EN/SAE value (tested at −18°C) — they are not comparable. See the main-site CCA article for the full explanation.

Conductance testers estimate — they do not load-test

Workshop conductance testers measure the battery's internal resistance/conductance and estimate CCA from it. They are fast and non-destructive, but they are not a 30-second cold-chamber discharge. Two things follow:

An estimate is only meaningful against a nominal CCA that used the same standard.
A measured CCA that drops far below nominal over time signals ageing — even though the absolute number is an estimate.

What to ask the lab

Which standard does the CCA rating use (SAE J537, EN 50342 or DIN)?
At what temperature was the test performed?
Was the battery fully charged before the test?

The temperature ladder

The rating name encodes the temperature: CCA tests at −18°C, CA/MCA at 0°C, and HCA at about 27°C — the same battery reads higher on each warmer rung, which is why the ladder exists and why the number without its rung is meaningless (see CCA vs CA).

Our Read

In my view: The most important thing a CCA test result must tell you is the standard, not just the number — a tester set to the wrong basis will "pass" or "fail" the same battery differently.

Why I think so: JIS and SAE differ by 3°C and a cut-off voltage, which is enough to move the printed value. If the test report does not name the basis, the number is a guess, not a measurement.

My editorial view, not a purchasing guarantee.

Sources

SAE J537 — cold cranking test method (−18°C, 30 s, 7.2V).
EN 50342, JIS D5301, DIN 43539 — standard variants.
Conductance-tester documentation (manufacturer manuals) — estimation vs load-test distinction.

Return to Battery Testing Methods · World Battery Hub. Informational, not purchasing advice.