Battery groups › 27R
BCI battery group
Group 27R battery size
A BCI group 27R battery is at most 306 mm long, 173 mm wide and 225 mm tall (12.05 × 6.81 × 8.86 in), according to the Battery Council International group chart.
| Maximum size | 306 × 173 × 225 mm |
|---|---|
| In inches | 12.05 × 6.81 × 8.86 |
| Terminal types | A and A2 |
| Polarity | Reversed (R): positive terminal on the opposite side from the base group |
| Cold cranking amps (OE range) | 270–700 A |
| JIS equivalents | 65D31L, 75D31L, 95D31L, 105D31L and 115D31L (BCI best fit) |
Cars whose manuals point to group 27R
None of the owner's manuals this site has read so far print group 27R. 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 27R
To take a group 27R, the tray needs at least 306 mm (12.05 in) of length and 173 mm (6.81 in) of width inside the hold-down, and 225 mm (8.86 in) of height below the hood or any bracket, with room left for the cable ends. These are BCI maximums: a real group 27R battery can be a few millimetres smaller, never larger. Original-equipment batteries in this group were rated from 270 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 27R |
|---|---|---|
| 27 | 306 × 173 × 225 | 0 mm length, 0 mm width, 0 mm height |
| 27F | 318 × 173 × 227 | +12 mm length, 0 mm width, +2 mm height |
| 77 | 306 × 184 × 222 | 0 mm length, +11 mm width, -3 mm height |
| 27H | 298 × 173 × 235 | -8 mm length, 0 mm width, +10 mm height |
| 64 | 296 × 162 × 225 | -10 mm length, -11 mm width, 0 mm height |
Positive numbers mean the other group is bigger than group 27R. 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 27R
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 6. Checked 2026-10-20.