A Group 24 battery is a common battery size used in many power systems.
The term “Group 24” refers to a standard battery size, not battery quality or brand.
Battery group sizes are defined by the Battery Council International (BCI).
BCI standards control the battery’s length, width, height, and terminal position.
This makes batteries easier to replace between brands and systems.
Understanding Group 24 size is important.
It helps ensure the battery fits correctly in the tray or box.
It also prevents wiring problems and safety risks.
Group 24 batteries are widely used by:
RV owners
Boat owners
Truck and bus operators
Off-grid and backup power users
Group 24 Battery Dimensions & Specifications
Standard Dimensions
According to BCI standards, a Group 24 battery has the following dimensions:
Length: 10.25 inches (260 mm)
Width: 6.8 inches (173 mm)
Height: 8.7–8.9 inches (about 225 mm)
These dimensions apply to most Group 24 batteries on the market.
Manufacturer Differences
Some brands may have small size differences.
For example:
Some lithium models may be slightly taller
Terminal height can vary
Built-in handles or BMS systems may add height
Because of this, height is the most important dimension to check before buying.
Key Electrical Specs
Voltage: 12V (standard)
Capacity:
Lead-acid: usually 70–85 Ah
Lithium (LiFePO₄): often 100 Ah
Even with the same size, lithium batteries usually provide more usable energy.
Weight Difference (Very Important)
Lead-acid Group 24: about 50–60 lbs (22–27 kg)
Lithium Group 24: about 20–25 lbs (9–11 kg)
Lithium batteries are often less than half the weight.
Battery Types & Chemistry
Lead-Acid Batteries
Common lead-acid types include:
Flooded
Gel
AGM
Advantages:
Lower upfront cost
Widely available
Disadvantages:
Heavy weight
Shorter lifespan
Lower energy density
Flooded batteries need water maintenance
Lead-acid batteries also suffer damage if deeply discharged too often.
Lithium Batteries (LiFePO₄) – Recommended Upgrade
Lithium iron phosphate (LiFePO₄) batteries are now very popular in Group 24 size.
Main benefits:
Much lighter
Longer lifespan (often 4000+ cycles)
Higher usable capacity
No watering or acid
Built-in BMS protection
Many modern lithium batteries also support:
Bluetooth monitoring
Low-temperature charging protection
Self-heating for cold climates
These features improve safety and ease of use.
Group 24 Size Comparisons
Group 24 vs Group 27
Group 27 is longer
Group 27 usually has higher capacity
Group 27 does not fit in a Group 24 tray
Choose Group 27 only if space allows.
Group 24 vs Group 31
Group 31 is much larger and heavier
Often used in trucks and industrial systems
Capacity is usually above 100 Ah
Group 31 needs stronger mounts and more space.
Size Compatibility Rule
Smaller batteries may fit into larger trays (with spacers)
Larger batteries cannot fit into smaller trays
Do not mix different group sizes in the same system
5. Common Applications
RVs & Campers
House batteries
Lights, fans, and appliances
Inverters and solar storage
Marine Systems
Trolling motors
House power
Navigation electronics
Heavy Vehicles & Equipment
Trucks and buses
Agricultural machines
Auxiliary power systems
Solar & Off-Grid Use
Small solar systems
Cabins and sheds
Other Uses
Wheelchairs
Medical backup power
Emergency systems
6. Maintenance Tips
Lead-Acid Battery Care
Check terminals for corrosion
Clean with baking soda and water
For flooded batteries, check water level
Avoid discharging below 50%
Poor maintenance reduces lifespan quickly.
Lithium Battery Care
Mostly maintenance-free
Use a compatible charger
Store in a dry place
Avoid charging below freezing unless supported
Lithium batteries are easier to manage long-term.
7. Buying Guide
How to Confirm Battery Size
Check the vehicle or equipment manual
Look for “Group 24” on the battery label
Measure the battery tray directly
Key Buying Factors
Climate:
Cold areas may need self-heating lithium batteriesEase of use:
Bluetooth monitoring is helpful for hard-to-reach batteriesBudget vs value:
Lithium costs more upfront but lasts much longer
Think long-term, not just purchase price.
8. Conclusion
The Group 24 battery is one of the most versatile battery sizes available.
It offers a good balance between size, capacity, and compatibility.
Standard dimensions are about:
10.25 × 6.8 × 8.8 inches
Lead-acid and lithium batteries share the same size, but performance is very different.
Lithium batteries are lighter, last longer, and require less maintenance.
Before buying, always confirm:
Exact dimensions
Weight limits
Application needs
Charging system compatibility
Choosing the right Group 24 battery will improve reliability and reduce future problems.
