Battery Group Sizes Explained: H4–H9, L1–L6, JIS and BCI
A battery "group size" is a standardized case dimension and terminal layout, so that any battery of that group fits the same tray and cables. The same physical battery has different names in different markets — the H6 sold in Europe is the L3 sold in North America — and understanding that mapping is the first step to buying the right battery.
The three naming families, and how they map
| DIN/EN name | BCI name | Typical use | Typical capacity | Typical CCA (EN) |
|---|---|---|---|---|
| H4 | L1 | Small / compact cars | ~55–60 Ah | ~500–600 A |
| H5 | L2 | Compact / midsize | ~60 Ah | ~600 A |
| H6 | L3 | Midsize / start-stop | ~70 Ah | ~640–700 A |
| H7 | L4 | Large cars / SUV | ~80 Ah | ~760 A |
| H8 | L5 | Large SUV / light truck | ~90–95 Ah | ~850–900 A |
| H9 | L6 | Heavy-duty / premium | ~105 Ah | ~950 A |
The H4–H9 ↔ L1–L6 mapping is a close physical equivalent, not a perfect one-to-one — always confirm length, width, height and terminal position against the original battery.
JIS and BCI heavy-duty groups
Japanese vehicles use the JIS naming — the "D23" case (55D23, 65D23, 75D23) for passenger cars, and the "N-series" (N150, N200) for trucks and heavy-duty. North American commercial vehicles use BCI Group 31 and 8D for trucks and diesel equipment. A European truck uses DIN; a Japanese truck uses JIS; a North American fleet uses BCI — the group name tells you which market's standard the vehicle was built around.
What group size does — and does not — tell you
- It tells you — the physical dimensions, terminal type, terminal position and polarity.
- It does not tell you — the CCA, capacity or technology (those vary within a group by design and chemistry).
This is why the correct sequence is group first, then CCA: match the group to the tray, then match the CCA to the engine and climate.
How to find your group size
- Read the code printed on the current battery — it is usually a group code (H6, L3, 55D23, etc.).
- Or measure the tray: length, width, height, and note the terminal position and polarity.
- Confirm the equivalent in your market's naming (H6 = L3), then match CCA and technology.
Key takeaways
- Group size = physical fit (case, terminals, polarity), not performance.
- DIN/EN (H4–H9) ≈ BCI (L1–L6): H4=L1 … H9=L6.
- JIS (D23, N-series) and BCI (Group 31/8D) cover Japanese and heavy-duty markets.
- Match the group to the tray first, then CCA to the engine and climate.
The Author's Take
Position: The most common battery-buying error is treating group size as a performance spec — when it is really just the answer to "will it fit and connect," and the performance questions (CCA, Ah) are asked separately.
Reasoning: Every market renames the same physical battery, which is why the same car can "need" an H6 in Europe and an L3 in North America. The buyer who learns the H4–H9 ↔ L1–L6 mapping stops being confused by the two names and starts comparing the numbers that actually differ — CCA and capacity.
This is the author's editorial view, not a purchasing guarantee.
Sources
Group mappings cross-verified from BCI group-size reference and manufacturer fitment guides (Varta, Bosch, Yuasa, Century, Exide). Typical CCA values are ranges, consistent with the CCA-by-group reference.
- Battery Council International (BCI) — group-size definitions.
- EN 50342, JIS D5301, SAE J537 — the standard families the groups belong to.
- Manufacturer fitment guides — H4–H9 / L1–L6 / JIS / BCI mappings.
Last reviewed: 2026-09-14