Technical insight

Battery Group Size Matching for Sodium-Ion Starter Batteries

Match LN, L, BCI, B and D battery case references to sodium-ion candidates, then verify dimensions, terminals, hold-downs, CCA and vehicle charging.

NaVolt Editorial Team 5 min read
NaVolt sodium-ion battery range for case size and model matching

Battery group size matching is a fast way to shortlist a replacement, but it is not installation approval. LN, L, T, BCI, B and D references can point a catalogue team toward the correct case family. The final choice still depends on the exact battery dimensions, hold-down, polarity, terminal design, CCA, voltage and charging system.

This distinction is essential when moving from conventional automotive posts to a sodium-ion battery with an M6 bolt interface.

What a group-size reference can tell you

Battery Council International describes group size as a system for standardizing dimensions, terminal location and related performance or fitment characteristics. BCI also publishes dimensional and assembly references for vehicle batteries.

A group-size name can help identify:

  • the general case envelope;
  • terminal position and polarity convention;
  • hold-down or assembly features;
  • a reference performance range;
  • catalogue cross-references.

It cannot confirm that every regional vehicle variant has the same tray, cable, bonnet clearance, battery sensor or charge profile.

Keep three records separate

Record Purpose Example
Current product specification Controls the battery being supplied H5: 245 × 175 × 190 mm, 40 Ah ±5%, 850 A CCA
Case-class cross-reference Helps shortlist equivalent market names LN2, L2, T5, Group 47 candidate class
Vehicle approval record Documents the exact installation tested Vehicle year, engine, market, terminals, charge data

Do not overwrite the current product dimensions with a dimension found in a catalogue or legacy fitment table. They answer different questions.

NaVolt’s internal fitment cross-reference is based on earlier vehicle checks. It is useful for candidate selection, but the current production sample still needs confirmation in the target vehicle.

Model Current dimensions (W × D × H) Current CCA Candidate case references Example application signals
H4-12V-400 207 × 175 × 190 mm 660 A LN1, L1, T5, Group 47 Compact A0/A-class cars
H5-12V-500 245 × 175 × 190 mm 850 A LN2, L2, T5, Group 47 Mainstream compact and midsize cars
H6-12V-600 281 × 175 × 190 mm 1,000 A LN3, L3, T6, Group 48 Larger passenger cars and SUVs
H7-12V-750 315 × 175 × 190 mm 1,200 A LN4, L4, T6, Group 94R Premium and high-load passenger vehicles
H8-12V-840 354 × 175 × 190 mm 1,400 A LN5, L5, T6, Group 49 Large SUVs and premium platforms
H9-12V-900 410 × 175 × 190 mm 1,600 A LN6, L6, T7, Group 95R Largest H-series vehicle class

The H8 and H9 dimensions do not exactly equal every conventional case reference shown. Treat the cross-reference as a search key and inspect the actual tray.

Model Current dimensions (W × D × H) Current CCA Candidate reference names
B19-12V-500 192 × 128 × 222 mm 500 A B19
B24-12V-660 238 × 130 × 222 mm 660 A 55B24 L/R, T5, H4, Group 26
D23-12V-850 231 × 175 × 222 mm 850 A 55D23 L/R, 75D23, Group 35
D26-12V-850 261 × 173 × 223 mm 850 A 55D26 L/R, 80D26, 95D26, Group 34
D31-12V-1000 306 × 173 × 222 mm 1,000 A 95D31 L/R, 115D31

The L/R notation makes polarity especially important. Define the viewing direction in the catalogue and use a photograph or terminal drawing. “Left positive” is ambiguous if two teams view the battery from opposite sides.

The M6 terminal is a separate fitment decision

All current NaVolt 12 V specifications list positive and negative terminals with an M6 bolt-type interface. This field does not prove compatibility with SAE, DIN or JIS tapered posts.

A connection approval should record:

  • lug or adapter part number;
  • conductor size and current capacity;
  • contact surface and plating;
  • tightening torque;
  • insulation and terminal cover;
  • cable reach and bend radius;
  • tool clearance and short-circuit protection.

Do not hide an unvalidated adapter inside a group-size equivalence claim.

Electrical matching follows physical matching

Once the case and terminals are workable, compare nominal voltage, CCA, capacity, continuous-current limits and charging. Current NaVolt 12 V specifications list a 15.8 V charge voltage and 6 V discharge cut-off. The vehicle profile must be reviewed against the battery requirement.

CCA should be compared using the same standard. SAE J537 is one recognized automotive storage-battery test reference. A legacy fitment table’s cold-start range must not overwrite the current product CCA field.

A catalogue approval workflow

Stage 1: Desk match

Use original-battery dimensions, voltage, CCA and group references to create a candidate list.

Stage 2: Sample inspection

Place the current production sample in the tray without connecting it. Verify hold-down engagement, lid clearance, polarity and cable reach.

Stage 3: Connection approval

Approve the terminal solution, torque, insulation and voltage drop under crank.

Stage 4: Vehicle test

Check starting, repeated start-stop, charging, battery sensor, registration, sleep current and diagnostic faults.

Stage 5: Catalogue release

Tie the listing to exact vehicle year, engine, market and installation notes. Keep photographs and test records available for warranty review.

Data fields for a fitment database

  1. Product model and revision
  2. Normalized L × W × H plus source dimension order
  3. Case-class references
  4. Terminal type, polarity and orientation photograph
  5. Hold-down and enclosure type
  6. Vehicle make, model, year, engine and market
  7. Original battery model, chemistry, Ah and CCA
  8. Charging and registration information
  9. Adapter or cable part number
  10. Approval status and reviewer

This structure prevents a group-size label from becoming the only evidence behind a warranty-sensitive listing.

Frequently asked questions

Is the same battery group size always interchangeable?

No. It is a strong shortlist signal, but case tolerances, terminals, polarity, hold-downs, cable routing and vehicle electrical requirements can differ. Inspect the exact installation.

Can a Group 47 battery and an LN2 battery be treated as identical?

They may appear together in cross-reference systems, but use the actual dimensional and assembly data from the applicable standard or catalogue. Then compare the current product drawing and vehicle.

Why does the product specification differ from a fitment table?

The product specification controls the manufactured battery. A fitment table records an equivalent class or earlier vehicle check. Keep both values with clear labels instead of forcing them into one field.

Does matching dimensions prove electrical compatibility?

No. Voltage, CCA, charging, continuous-current limits, battery sensors and start-stop controls still need approval.

Conclusion

Battery group size matching gets a buyer to the candidate list. The product specification, terminal design and vehicle test decide whether the candidate can become an approved replacement.

Compare NaVolt starter and start-stop models or request a model and vehicle fitment review.

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