JIS vs DIN vs BCI: Why CCA Cannot Be Compared Directly
A 900A CCA battery under JIS and a 900A CCA battery under EN are not the same battery. Each standard tests at a different temperature, duration and cut-off voltage, so the printed number moves — and the ratings are not interchangeable.
The four standards, and how each moves the number
| Standard | Test temperature | Duration | Cut-off voltage | Effect on CCA |
|---|---|---|---|---|
| JIS D 5301 | −15°C | 30 s | reference | Warmer test → higher number |
| SAE J537 | −18°C | 30 s | 7.2 V | Baseline |
| EN 50342 | −18°C | 10 s | 7.5 V | Shorter, higher cut-off → higher number |
| DIN 43539 | −18°C | 30 s | 9.0 V | Higher cut-off → lower number |
Why the numbers diverge
Three test variables move the printed CCA, and each standard sets them differently. A warmer test lets the battery deliver more current, so JIS (−15°C) reads higher than EN/SAE (−18°C) for the same battery. A lower cut-off voltage lets the battery sag further before the test stops, also raising the number. A shorter duration is easier to sustain, so a 10-second EN test reads higher than a 30-second SAE test.
These are not battery differences — they are test-method differences. There is no universal percentage conversion between standards, which is why any conversion chart is an approximation, not a measurement.
How to compare correctly
- Confirm the standard first — ask whether the number is JIS, EN, SAE or DIN.
- Compare within one standard — only JIS with JIS, EN with EN.
- Check nominal vs batch-tested — a catalogue value is a design target; the batch you receive varies within tolerance.
What to put in the specification
A CCA number without its standard is meaningless. A complete spec states the standard (for example JIS D 5301), the CCA value, the group size and terminal orientation, and whether the value is nominal or batch-tested. See the N150 vs N200 comparison for how this applies to DINWEY's JIS range, and the selection tool to match a vehicle.
The Author’s Take
Position: In my view, most CCA confusion is not about the battery — it is about comparing numbers that were measured under different rules, and the fix is simply to state the standard next to every number.
Reasoning: A JIS CCA of 900 and an EN CCA of 900 can describe the same battery. The buyer who compares raw numbers across standards is comparing test methods, not products. A supplier who states the standard beside every rating removes the ambiguity; a buyer who asks for it removes the risk.
Disclosure: This is my editorial view as a battery manufacturer’s technical team, not a laboratory claim. Confirm the final CCA, its test basis and whether it is nominal or batch-tested with the manufacturer.
Frequently Asked Questions
Can I compare a JIS CCA with an EN or SAE CCA?
No — JIS tests at −15°C while EN/SAE test at −18°C, with different cut-off voltages and durations. The same battery carries a different number under each standard, so compare only within one standard.
Why does JIS CCA look higher than EN CCA?
Because JIS tests at a warmer −15°C versus EN/SAE's −18°C. A warmer test lets the battery deliver more current, so the JIS number is higher for the same battery — the difference is the test, not the battery.
What should I specify when buying a truck battery?
Specify the standard (JIS, DIN/EN or BCI/SAE), the CCA value, whether it is nominal or batch-tested, and the group size and terminal orientation.
Technical review — Reviewed by the DINWEY technical team. Manufacturer: Chengguang Power Tech Co., Ltd. Data source: manufacturer specification and test documentation. Specifications vary by model and standard; confirm final values with the manufacturer.