Car Battery Sizes: BCI Group Size Chart with Dimensions
Car batteries are sold by group size, a code that fixes the case dimensions and terminal layout so the battery fits the tray, the hold-down and the cables. Here are the dimensions of every common group and how to find yours.
Car battery sizes are set by the BCI group number. The most common groups are 24F (10.25 × 6.8 × 8.9 in, 260 × 173 × 225 mm), 35 (9.1 × 6.9 × 8.9 in, 230 × 175 × 225 mm), 48/H6 (10.9 × 6.9 × 7.5 in, 278 × 175 × 190 mm) and 65 (12.1 × 7.5 × 7.6 in, 306 × 190 × 192 mm). Your vehicle's group is on the old battery's label and in the owner's manual.
- Group 24F
- 260 × 173 × 225 mm
- Group 35
- 230 × 175 × 225 mm
- Group 48 (H6)
- 278 × 175 × 190 mm
- Group 65
- 306 × 190 × 192 mm
On this page
Car battery group size chart
Dimensions are the maximum case size (length × width × height, including the terminals on top-post batteries). Individual brands vary by a few millimeters within each group, which is why the tray, not the label, is the final check.
| Group | Inches (L × W × H) | Millimeters | Terminals | Commonly found in |
|---|---|---|---|---|
| 24 / 24F | 10.25 × 6.81 × 8.88 | 260 × 173 × 225 | Top post | Toyota, Lexus, Honda, Nissan, older domestic cars |
| 25 | 9.06 × 6.88 × 8.88 | 230 × 175 × 225 | Top post | Honda and Acura models |
| 26 / 26R | 8.19 × 6.81 × 7.75 | 208 × 173 × 197 | Top post | Older small cars |
| 27 / 27F | 12.06 × 6.81 × 8.88 | 306 × 173 × 225 | Top post | Some trucks, RVs, marine |
| 31 | 12.94 × 6.81 × 9.44 | 330 × 173 × 240 | Stud or top post | Heavy trucks, equipment, commercial |
| 34 | 10.25 × 6.81 × 7.88 | 260 × 173 × 200 | Top post | Chrysler, Dodge and Jeep models |
| 35 | 9.06 × 6.88 × 8.88 | 230 × 175 × 225 | Top post | Many Toyota, Nissan, Honda and Subaru cars |
| 40R | 10.94 × 6.88 × 6.88 | 278 × 175 × 175 | Top post (recessed) | Some GM and European cars |
| 47 (H5, L2) | 9.56 × 6.88 × 7.50 | 242 × 175 × 190 | Top post (recessed) | Compact cars, many VW and GM models |
| 48 (H6, L3) | 10.94 × 6.88 × 7.50 | 278 × 175 × 190 | Top post (recessed) | GM, Ford, Jeep, VW, BMW, many crossovers |
| 49 (H8, L5) | 13.94 × 6.88 × 7.50 | 353 × 175 × 190 | Top post (recessed) | Larger European cars, some Hyundai and Kia |
| 51 / 51R | 9.38 × 5.06 × 8.81 | 238 × 129 × 223 | Top post | Honda Civic, Fit and other small cars |
| 58 / 58R | 10.06 × 7.25 × 6.88 | 255 × 184 × 175 | Top post | Some Ford and Mazda models |
| 65 | 12.06 × 7.50 × 7.56 | 306 × 190 × 192 | Top post | Ford and Lincoln trucks and SUVs |
| 75 | 9.06 × 7.06 × 7.31 | 230 × 180 × 186 | Side terminal | GM cars |
| 78 | 10.25 × 7.06 × 7.31 | 260 × 180 × 186 | Side terminal | GM trucks and cars |
| 86 | 9.06 × 6.81 × 7.88 | 230 × 173 × 200 | Top post | Some Toyota and older domestic cars |
| 94R (H7, L4) | 12.38 × 6.88 × 7.50 | 315 × 175 × 190 | Top post (recessed) | Ram, Jeep, Ford, GM, European cars, start-stop vehicles |
| 96R | 9.56 × 6.88 × 6.88 | 242 × 175 × 175 | Top post (recessed) | Ford compact cars |
The "commonly found in" column is a guide only. Automakers change groups between models and engines, so look up your exact vehicle.
How to find your battery group size
- Read the old battery. The group number is printed on the top or side label: "Group 35", "H6", "48" or "94R".
- Check the owner's manual. The specifications section lists the group or the DIN/EN size and the minimum CCA.
- Use a retailer or battery maker lookup by year, make, model and engine. Engine matters: the same model can take a different group with a diesel or hybrid powertrain.
- Measure the tray if the label is gone. Measure the tray's length and width, the height available to the hood, and note which side the positive terminal sits on as you face the battery. Match those to the chart.
Stand at the front of the vehicle and note whether the positive (red) cable reaches the left or right post. A battery of the right size with the terminals swapped (24 vs 24F, 51 vs 51R) will not connect without stretching the cables.
H5, H6, H7, H8: DIN and EN battery sizes
European and many newer American vehicles use EN/DIN case sizes, all 175 mm (6.9 in) wide and 190 mm (7.5 in) tall with recessed terminals and a base ledge for the hold-down clamp. The length increases with capacity.
| EN / DIN name | Also called | BCI group | Length |
|---|---|---|---|
| H5 | L2, LN2 | 47 | 242 mm (9.56 in) |
| H6 | L3, LN3 | 48 | 278 mm (10.94 in) |
| H7 | L4, LN4 | 94R | 315 mm (12.38 in) |
| H8 | L5, LN5 | 49 | 353 mm (13.94 in) |
Japanese JIS battery codes
Batteries for the Asian market use JIS codes such as 55B24L. Read them as: 55 = performance rank (higher is stronger), B = the case width and height class, 24 = length in centimeters (about 24 cm), L = terminal position. Case class B is about 129 mm wide, the same width as a BCI group 51; class D is about 173 mm, the same as group 24 and 35.
CCA, reserve capacity and amp-hours
A battery that fits physically must also deliver enough power. Three ratings matter:
- Cold cranking amps (CCA): the current a 12 V battery delivers at 0°F (-18°C) for 30 seconds while staying above 7.2 V. Buy at least the CCA your manual specifies. Most cars need 400-700 CCA; large V8 and diesel engines need 750-1,000 or more.
- Reserve capacity (RC): minutes the battery can supply 25 A at 80°F (27°C) before falling to 10.5 V. It indicates how long the car can run lights and electronics if the alternator fails. Typical values are 80-140 minutes.
- Amp-hours (Ah): the standard rating on EN/DIN batteries, measured over 20 hours. H6 batteries are typically 60-75 Ah and H7 batteries 75-95 Ah.
| Group | Typical CCA | Approx. weight |
|---|---|---|
| 51R | 410-500 | 25-30 lb (11-14 kg) |
| 35 | 550-650 | 35-45 lb (16-20 kg) |
| 24F | 550-750 | 40-50 lb (18-23 kg) |
| 48 (H6) | 650-760 | 40-55 lb (18-25 kg) |
| 65 | 750-850 | 45-55 lb (20-25 kg) |
| 94R (H7) | 750-850 | 50-60 lb (23-27 kg) |
| 49 (H8) | 850-900 | 55-65 lb (25-29 kg) |
Battery types: flooded, EFB, AGM and lithium
- Flooded (standard lead-acid): the traditional and least expensive type. Fine for vehicles without start-stop.
- EFB (enhanced flooded): a tougher flooded battery for basic start-stop systems.
- AGM (absorbent glass mat): sealed, vibration-resistant and better at deep cycling. Required by many start-stop vehicles and cars with heavy electrical loads. Replace AGM with AGM; a flooded battery in an AGM car wears out quickly and can trigger warnings.
- Lithium (LiFePO4): very light, used mainly in performance and some electric vehicles' 12 V systems. Only fit one where the maker approves it, because charging requirements differ.
Many BMW, Audi, VW, Mercedes and some Ford and GM vehicles monitor battery age and type. After a replacement, the new battery must be registered with a scan tool so the charging system adjusts. Skipping it can overcharge the new battery and shorten its life.
Terminal types and hood clearance
- SAE top posts: tapered posts; the positive post is larger (about 17.5 mm across the top) than the negative (about 15.9 mm), so clamps cannot be swapped by accident.
- Side terminals: GM-style threaded holes for 3/8-16 bolts on the side of the case (groups 70, 74, 75, 78). Dual-terminal batteries (34/78, 75/86) have both.
- Height: a taller group (225 mm group 24 vs 190 mm H6) can touch the hood or the hood insulation and short against metal. Check before substituting a taller case.
For AA, AAA, coin and other household battery sizes, see the battery size chart. Other routine replacement parts are covered in the wiper blade size guide and the tire size guide.
Frequently asked questions
What does the R or F in a battery group size mean?
Both indicate reversed terminals compared with the base group. A 24F has the same case as a group 24 but the positive and negative posts on opposite sides; 51R and 94R work the same way. Using the wrong orientation can leave the cables too short to reach.
Can I use a different battery group size?
Only if it fits the tray and hold-down, the terminals are in the same positions, the case clears the hood, and it meets the vehicle's CCA and type (AGM, EFB) requirements. Some groups are close: 34 and 78 share the same case footprint, and 34/78 dual-terminal batteries are sold to cover both.
Which car batteries are 20 cm tall?
Group 34 and group 86 are both about 200 mm (7.9 in) tall. The DIN-style H5, H6, H7 and H8 batteries (groups 47, 48, 94R, 49) are 190 mm (7.5 in) tall, and group 24 and 35 are 225 mm (8.9 in).
What is the most common car battery size?
There is no single most common size because each automaker standardizes on a few groups. Groups 24F, 35, 48 (H6), 65 and 94R (H7) together cover a large share of current cars, SUVs and pickups in North America, and group 51R covers many small Hondas.
How much does a car battery weigh?
Most passenger car batteries weigh 30-60 lb (14-27 kg). A small group 51R is around 25-30 lb, groups 24F and 35 are typically 35-50 lb, and large AGM batteries in groups 49 (H8) and 94R (H7) can reach 55-65 lb (25-29 kg).
How long does a car battery last?
Typically three to five years. Heat shortens battery life more than cold, so batteries in hot climates often fail sooner. A resting voltage below about 12.4 V with the engine off for several hours means the battery is less than 75% charged.