BCI Battery Size Chart & Guide

BCI Battery Size Chart & Guide

The Battery Council International (BCI) group size system classifies batteries based on their physical dimensions, terminal placement, and general application. Choosing the correct BCI group size helps ensure proper fitment and reliable performance in automotive, marine, RV, golf cart, lawn & garden, and backup power applications. This BCI Battery Size Chart & Guide provides a quick reference to common battery group sizes and dimensions, along with helpful information to assist you in selecting the right replacement battery for your application. Many of these battery sizes are available for in-store pickup in Toronto and shipping across Canada.

Automotive Battery Sizes

Common automotive battery group sizes and dimensions. Use this chart to compare battery sizes and help identify the correct replacement battery for your car, truck, SUV, or commercial vehicle.

BCI SizeL (mm)W (mm)H (mm)L (in)W (in)H (in)
2426017322510 1/46 13/168 7/8
24R26017322510 1/46 13/168 7/8
26R2081731978 3/166 13/167 3/4
31330173240136 13/169 7/16
352301752259 1/166 15/168 7/8
40R278175175116 15/166 15/16
47 (H5)2421751909 9/166 15/167 1/2
48 (H6)278175190116 15/167 1/2
49 (H8)35317519013 15/166 15/167 1/2
51R2381292239 3/85 1/168 3/4
6530619219212 1/167 9/167 9/16
752301801869 1/167 1/167 5/16
7826018018610 1/47 1/167 5/16
94R (H7)31517519012 7/166 15/167 1/2
95R (H9)39417519015 9/166 15/167 1/2

Marine / Deep Cycle Battery Sizes

Common marine and deep cycle battery group sizes and dimensions. These battery sizes are frequently used in boats, RVs, golf carts, floor machines, solar systems, and other deep cycle applications.

BCI SizeL (mm)W (mm)H (mm)L (in)W (in)H (in)
24DC26017322510 1/46 13/168 7/8
27DC306173225121/166 13/168 7/8
31DC330173240136 13/1697/16
GC226418329010 3/87 3/1611 7/16
GC826418329010 3/87 3/1611 7/16
GC1232718327712 7/87 3/1610 7/8
4D52722225020 3/48 3/49 13/16
8D52728325020 3/411 1/89 13/16
GC226418329010 3/873/1611 7/16
GC826418329010 3/873/1611 7/16
GC1232718327712 7/87 3/1610 7/8
L16 (903)302181432127 1/817

How to Choose the Right BCI Group Size

When selecting a battery, always match the physical group size first to ensure it fits properly in your battery tray. After confirming size, consider the following:

  • Capacity (Ah) – Determines how long the battery will run.
  • Battery Type – AGM, flooded, gel, or lithium.
  • Application – Starting, deep cycle, or dual purpose.
  • Terminal Position – Ensures correct cable connections.

Common Battery Selection Mistakes

  • Choosing the wrong size – Even small differences can prevent proper installation.
  • Mixing battery types – Can reduce performance and lifespan.
  • Ignoring terminal layout – May cause connection issues.
  • Undersizing capacity – Leads to shorter runtime and premature wear.

Frequently Asked Questions

What is a BCI group size?

A BCI group size defines the battery’s physical dimensions, terminal placement, and general application category.

Can I use a different group size battery?

It is best to use the recommended group size. Using a different size may cause fitment or performance issues unless the battery tray and connections are modified.

What are GC2 batteries used for?

GC2 batteries are widely used in golf carts, floor scrubbers, industrial equipment, and off-grid solar applications. They are built for deep cycle performance, providing reliable power over long periods of use.

What is Group 31 used for?

Group 31 batteries are commonly used in marine, commercial, and heavy-duty applications requiring higher capacity and durability.