Battery groups › 91
BCI battery group
Group 91 battery size
A BCI group 91 battery is at most 278 mm long, 175 mm wide and 175 mm tall (10.94 × 6.89 × 6.89 in), according to the Battery Council International group chart.
| Maximum size | 278 × 175 × 175 mm |
|---|---|
| In inches | 10.94 × 6.89 × 6.89 |
| Terminal types | A1 and A2 |
| Polarity | Standard layout for this group |
| Cold cranking amps (OE range) | 590–700 A |
| DIN / EN equivalent | T6 / LBN3 (BCI best fit) |
Cars whose manuals point to group 91
None of the owner's manuals this site has read so far print group 91. Most Japanese and Korean makers print a case size or capacity instead of a BCI group, so the battery label on the car is the better guide.
Measuring for a group 91
To take a group 91, the tray needs at least 278 mm (10.94 in) of length and 175 mm (6.89 in) of width inside the hold-down, and 175 mm (6.89 in) of height below the hood or any bracket, with room left for the cable ends. These are BCI maximums: a real group 91 battery can be a few millimetres smaller, never larger. Original-equipment batteries in this group were rated from 590 to 700 cold cranking amps, so the right rating depends on the car; match or exceed the rating on the battery you are replacing.
Nearby sizes
| Group | L × W × H (mm) | Difference from 91 |
|---|---|---|
| 40R | 278 × 175 × 175 | 0 mm length, 0 mm width, 0 mm height |
| 41 | 293 × 175 × 175 | +15 mm length, 0 mm width, 0 mm height |
| 48 | 278 × 175 × 190 | 0 mm length, 0 mm width, +15 mm height |
| 148 | 278 × 175 × 190 | 0 mm length, 0 mm width, +15 mm height |
| 98R | 283 × 175 × 190 | +5 mm length, 0 mm width, +15 mm height |
Positive numbers mean the other group is bigger than group 91. A bigger case only fits if your tray and hold-down have that much spare room; measure inside the hold-down frame, not the old battery.
Fitting a group 91
The group sets the case size, terminal position and hold-down. A battery from another group can only replace it when the length, width and height all fit the tray and the terminals land on the same sides. No other passenger-car group in the BCI chart has exactly the same case size and polarity. Use the tray fit checker to list every group that fits a measured space.
Source: Battery Council International, BCI Group Sizes (Oct 2023 PDF), page 7. Checked 2026-10-20.