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.
What do the battery group size codes mean?
| 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.
What are JIS and BCI heavy-duty group sizes?
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.
Does the group size tell you the battery's performance?
- 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 do I find my car's battery 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 cross-market equivalent in your market's naming (H6 ≈ L3), then verify dimensions and 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 — close physical equivalents, not a universal interchangeability rule.
- 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.
Cross-family reference: the same capacity class in three naming systems
| Capacity class | EN / DIN | JIS | BCI / SAE |
|---|---|---|---|
| ~55–60 Ah | H4 | 55D23 | Group 34 |
| ~60–65 Ah | H5 | 65D23 | — |
| ~70–75 Ah | H6 | N70 | Group 24, Group 65 |
| ~70–80 Ah | H7 | — | — |
| ~90–95 Ah | H8 | — | Group 27, Group 49 |
| ~100–105 Ah | H9 | N100 | Group 31 |
| ~120 Ah | — | N120 | — |
| ~200+ Ah | — | N200 | Group 8D |
Capacity-class comparison compiled from the World Battery Hub entity database (23 groups) — see individual group pages such as H4, H6, 55D23 and Group 31. It is not a physical-interchange table — dimensions, terminal types and hold-downs differ between naming families; always match the vehicle's group code first.
The bottom line
Match the group first (physical fit), then the ratings — a battery that fits is the start; one that fits and carries the right CCA standard is the finish.
Our Interpretation
My read: 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.
The 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.
My editorial view, not a purchasing guarantee.
Frequently asked questions
What is a battery group size?
A standardized case dimension and terminal layout, so any battery of that group fits the same tray and cables. It is a physical-fit spec, not a performance spec — CCA and Ah vary within a group by design.
What is the difference between H6 and L3?
They are commonly used cross-market equivalents — H6 is the DIN/EN name and L3 is the BCI name for the same case: H4≈L1, H5≈L2, H6≈L3, H7≈L4, H8≈L5, H9≈L6. This is a cross-reference, not a universal interchangeability rule: verify dimensions, terminal position, hold-down and polarity before substituting.
What buyers should ask
- Which group size (and terminal layout) does the vehicle's tray, cables and clamp actually require?
- Does the group number come from BCI, JIS or DIN — and are you comparing within one naming system?
- Is the required terminal position (positive-left or positive-right) correct for the cable reach?
- Can a different group with the same capacity class be physically fitted, or is the case dimension fixed?
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