What is a Group 40R Battery: Technical Information and Comparison with Alternatives

Group 40R Battery Dimensions

Battery of this group has the positive post terminal located on the right. It is marked with the letter "R" because this post terminal position is called Reverse Polarity of Battery. Most batteries have it on the left side. If you want the positive post terminal to be on the left, you can turn around the 40R battery and use it as a group 40 battery, because they have identical dimensions. This will allow you to use the positive post on the left. Make sure you have enough cable length to reach the terminals, because in the turned position the terminals can be located a little further.

Battery Design

Dimensions and Sizes (Length x Width x Height)
11'' x 6.9375'' x 6.9375'' Inches 278 x 175 x 175 Millimeters

Group 40R Battery Post Terminals

Post Terminal Types and Locations	Posts Used
	Type "A", "A1" or manufacturer's custom post design

Group 40R Battery Voltage and Current Characteristics

Volts	Cells	CCA Range
12	6	550-650

Group 40R Alternatives and Closest Battery Groups by Dimensions

Interchangeable Battery Groups for 40R Battery

These groups have the same dimensions and performance but can have different terminal post types, post locations, and polarity.

Battery Group Number	Dimensions	Shape	Volts	Cells	Post Terminal Type
Group 40R Battery	11'' x 6.9375'' x 6.9375'' in. 278 x 175 x 175 mm Positive post on the Right		12	6	"A", "A1"
Group 91 Battery	11'' x 6.9375'' x 6.9375'' in. 278 x 175 x 175 mm		12	6	"A1", "A2"

Similar Battery Groups With the Same Length, Width and Voltage

These dimensions will fit you in 99% of cases when you want to use a different battery group instead of a 40R battery since most battery compartments have a height margin and strict limitations on height and width only, which match batteries in the table below. Please check the battery compartment before you buy a battery from this group.

Battery Group Number	Dimensions	Shape	Volts	Cells	Post Terminal Type
Group 40R Battery	11'' x 6.9375'' x 6.9375'' in. 278 x 175 x 175 mm Positive post on the Right		12	6	"A", "A1"
Group 48 Battery	11'' x 6.9375'' x 7.5'' in. 278 x 175 x 190 mm		12	6	"A", "A1", "A2"

Closest but not Identical Size Battery Groups

Battery groups in this section below are not identical to the group 40R battery, they can be a little bigger or smaller. Please pay attention to the post terminal types and their location

Closest Groups that Have Slightly Smaller Dimensions

Smaller batteries can have less capacity, performance, and power in comparison with 40R group.

Battery Group Number	Dimensions	Shape	Volts	Cells	Post Terminal Type
Group 40R Battery	11'' x 6.9375'' x 6.9375'' in. 278 x 175 x 175 mm Positive post on the Right		12	6	"A", "A1"
Group 124 Battery	10.4375'' x 6.9375'' x 8.4375'' in. 265 x 175 x 214 mm		12	6	"A"
Group 34R Battery	10.25'' x 6.8125'' x 7.875'' in. 260 x 173 x 200 mm Positive post on the Right		12	6	"A"
Group 34 Battery	10.25'' x 6.8125'' x 7.875'' in. 260 x 173 x 200 mm		12	6	"A"
Group 56 Battery	10'' x 6.0625'' x 8.375'' in. 254 x 154 x 212 mm		12	6	"A"
Group 97R Battery	9.9375'' x 6.9375'' x 7.5'' in. 252 x 175 x 190 mm Positive post on the Right		12	6	"A1", "A2"

Closest Large Dimensions

Bigger batteries can have more capacity and power compared to 40R batteries.

Battery Group Number	Dimensions	Shape	Volts	Cells	Post Terminal Type
Group 40R Battery	11'' x 6.9375'' x 6.9375'' in. 278 x 175 x 175 mm Positive post on the Right		12	6	"A", "A1"
Group 98R Battery	11.125'' x 6.9375'' x 7.5'' in. 283 x 175 x 190 mm Positive post on the Right		12	6	"A1", "A2"
Group 41 Battery	11.5625'' x 6.9375'' x 6.9375'' in. 293 x 175 x 175 mm		12	6	"A", "A1"
Group 79 Battery	12.0625'' x 7.0625'' x 7.375'' in. 307 x 179 x 188 mm		12	6	"S"
Group 65 Battery	12.0625'' x 7.5625'' x 7.5625'' in. 306 x 192 x 192 mm		12	6	"A"
Group 66 Battery	12.0625'' x 7.5625'' x 7.6875'' in. 306 x 192 x 194 mm		12	6	"A"
Group 92 Battery	12.4375'' x 6.9375'' x 6.9375'' in. 315 x 175 x 175 mm		12	6	"A1", "A2"
Group 94R Battery	12.4375'' x 6.9375'' x 7.5'' in. 315 x 175 x 190 mm Positive post on the Right		12	6	"A1", "A2"

How to Get 24 Volts from 12V of a 40R Battery Group

If you need 24 Volts, you can connect two group 40R batteries in series to double the voltage. The voltage of a series connection is equal to the sum of the voltages of all its batteries. If one 12V lead-acid battery is connected to another 12V lead-acid battery, you have 24V total power output. Each battery must be fully charged and completely isolated from the other before connecting them in series, or there will be damage to at least one of them.

Increasing a Capacity of 40R Batteries with a Parallel Connection

If you need to increase current capacity and reduce charging time, connect batteries in parallel. When group 40R batteries are in parallel, their voltage is equal to the voltage of one battery, while current capacity equals to the sum of all its battery capacities. If you have two 12V lead-acid batteries with 60 Ah capacity and you connect them in parallel, you'll get 12 Volts with 120 Ah.