Battery Equivalents and Replacements

BCI Group 24 vs Group 27 Battery

BCI Group 24 batteries and BCI Group 27 batteries are very similar batteries in terms of dimensions, battery types, chemistry, and in the end, their intended use.

However, these batteries are not exactly the same and they should not be used interchangeably unless explicitly permitted by the manufacturer of the intended application/service/tool.

Published: July 20, 2021.

mighty max ml75 12 m

BCI Group 24 Battery Dimensions

BCI Group 24 batteries feature dimensions of (L x W x H) 10.25 x 6.8125 x 8.875 inches (260 x 173 x 225 mm), but there are other subgroups present as well:

BCI Group Size L x W x H (mm) L x W x H (inches)
24 260 x 173 x 225 10 1/4 x 6 13/16 x 8 7/8
24F 273 x 173 x 229 10 3/4 x 6 13/16 x 9
24H 260 x 173 x 238 10 1/4 x 6 13/16 x 9 3/8
24R 260 x 173 x 229 10 1/4 x 6 13/16 x 9
24T 260 x 173 x 248 10 1/4 x 6 13/16 x 9 3/4

As one can see, BCI Group 24 batteries differ in length and height. However, they also differ in chemistry, battery type, terminal type and orientation, and similar - when looking for a new battery, be sure to check the actual battery size, type, chemistry, terminal type and orientation.

Note: this goes not only for the group 24 batteries but for all battery sizes in general.

BCI Group 27 Battery Dimensions

BCI Group 27 batteries feature dimensions of (L x W x H) 12.0625 x 6.8125 x 8.875 inches (306 x 173 x 225 mm), but there are other subgroups present as well:

BCI Group Size L x W x H (mm) L x W x H (inches)
27 306 x 173 x 225 12 1/16 x 6 13/16 x 8 7/8
27F 318 x 173 x 227 12 1/2 x 6 13/16 x 8 15/16
27H 298 x 173 x 235 11 3/4 x 6 13/16 x 9 1/4

BCI Group 27 batteries also differ in length and height, just like group 24 batteries.

When comparing group 24 and group 257 batteries, "standard" group 24 and group 27 sizes are used (L x W x H):

- Group 24 dimensions: 10.25 x 6.8125 x 8.875 inches (260 x 173 x 225 mm),

- Group 27 dimensions: 12.0625 x 6.8125 x 8.875 inches (306 x 173 x 225 mm).

The actual difference in size between groups 24 and 27 is 1.8125 inches (46 mm) in length, while the width and height are the same (W: 6.8125 inches (173 mm), H: 8.875 inches (225 mm)).

Because of this difference, battery compartments intended for the group 27 batteries may accept group 24 batteries, while the battery compartments intended for the group 24 batteries generally cannot accept group 27 batteries.

And because of the larger volume of the group 27 batteries, group 27 batteries feature larger capacity, and better CCA, MCA, and RC ratings.

Most Popular Group 24 and Group 27 Batteries

The following comparison chart lists some of the most popular group 24 batteries:

Model

Battery Type

Chemistry

Capacity(Ah)

RC (min)

CCA

MCA

Weight (lbs/kg)

Review

ACDelco M24AGM

Deep Cycle

AGM

80

140

500

625

43.0 lbs; ~19.5 kg

-

Exide Edge FP-AGM24DP

Dual Purpose

AGM

75

145

775

930

50 lbs; ~22.7 kg

Review

Lifeline GPL-24T

Deep Cycle

AGM

80

149

550

680

56 lbs; 25.5 kg

-

Mighty Max ML75-12

Deep Cycle

AGM

77

-

-

-

50.71 lbs;  ~22.97 kg

Review

NorthStar NSB-AGM24F

Dual Purpose

AGM

76

160

840

1000

57 lbs;  ~25.8 kg

-

UPG UB12750

Deep Cycle 

AGM

75

-

-

-

49.1 lbs;  ~22.3 kg

Review

VMAXTANKS MB107-85

Deep Cycle 

AGM

85

170

-

-

55 lbs; ~24.9 kg

Review

VMAXTANKS MR107-85

Deep Cycle 

AGM

85

160

-

700

55 lbs; ~24.9 kg 

Review

VMAXTANKS SLR-85

Deep Cycle 

AGM

85

180

-

-

55 lbs; ~24.9 kg 

Review

Weize FP12750/TL1275

Deep Cycle

AGM

77

-

-

-

46 lbs; 20.9 kg

Review

Note: Amazon links in the table open in the new windows ('Model' column), so feel free to check them for the most up-to-date prices and offers.

On average, group 24 batteries are mostly deep cycle batteries with nominal (20h) capacity of 75-85 Ah, Reserve Capacity of 140-180 minutes and they weigh 43-57 pounds.

Most group 24 batteries are not intended for high-current applications, but some models feature a CCA rating of 500-840 Amps and an MCA rating of 625-100 Amps, allowing them to be used even as starting batteries for smaller gas and diesel engines.

The following comparison chart lists some of the most popular group 27 batteries:

Model

Battery Type

Chemistry

Capacity (Ah)

RC (min)

CCA

MCA

Weight

Review

Banshee 27M

Dual Purpose

Enhanced Flooded

77

140

800

1000

51 lbs; 23.1 kg

-

Banshee LFP-27M

Dual Purpose

LiFePO4

70

~165

900

-

18.8 lbs; 8.52 kg

-

GreenLiFE GL80-80AH

Deep Cycle

LiFePO4

80

~190

-

-

28 lbs; 12.8 kg

-

Mighty Max ML100-12

Deep Cycle

AGM

100

-

-

-

63.9 lbs; 29 kg

Review

NorthStar NSB-AGM27

Dual Purpose

AGM

92

195

930

1080

68 lbs; 31 kg

Review

Optima 8027-127 D27M

Dual Purpose

AGM

66

140

800

1000

54 lbs; 24.5 kg

Review

Renogy RBT100LFP12S-G1

Deep Cycle

LiFePO4

100

~200

100A cont.

26 lbs; 11.8 kg

-

UPG UB121000

Deep Cycle

AGM

100

170

-

-

64 lbs; 29 kg

Review

VMAXTANKS MR127-100

Deep Cycle

AGM

100

200

-

800

68 lbs; 31 kg

Review

VMAXTANKS SLR100

Deep Cycle

AGM

100

220

-

-

68 lbs; 31 kg

-

VMAXTANKS XTR27-110

 Deep Cycle

AGM

110

220

660

880

68 lbs; 31 kg

Review

Note: Amazon links in the table open in the new windows ('Model' column), so feel free to check them for the most up-to-date prices and offers.

On average, group 27 batteries are mostly deep cycle batteries with nominal (20h) capacity of 80-110 Ah, Reserve Capacity of 170-220 minutes and they weigh 64-68 pounds.

While most group 27 batteries are deep cycle batteries, there are also several true dual-purpose batteries, including Optima D27M with spiral wound cells and NorthStar NSB-AGM27 with flat-plate cells.

Because of the spiral wound cells, Optima D27M battery is somewhat lighter than other group 27 batteries and features a relatively modest capacity of 66 Ah and RC of 140 minutes, but it also features an MCA rating of 1000 Amps and it weighs only 54 pounds.

nsb agm27NorthStar NSB-AGM27 battery is one of the heaviest group 27 batteries (68 pounds) and it features a somewhat smaller capacity (92 Ah) and RC rating (195 minutes) than true deep cycle group 27 batteries, but it also features an MCA rating of 1080 Amps.

Both Optima D27M and NorthStar NSB-AGM27 are very popular dual-purpose batteries that cycle well but are also able to crank surprisingly large gas and diesel engines.

Lithium Group 24 and Group 27 Batteries

Lithium group 24 and group 27 batteries are not as common as AGM lead-acid batteries, but they support a much larger number of charging/discharging cycles and they are much lighter.

On the other hand, lithium batteries initially cost more and must be recharged using either dedicated lithium battery chargers or using smart AGM battery chargers that feature dedicated lithium battery charging modes.

greenlife gl80 group27

An important feature of the lithium group 24/27 batteries are their built-in Battery Management Systems (MBS) that monitor the batteries' operation and protect the battery from unwanted events like overcharge, over-discharge, short circuit, overheating, low temperature, etc.

If You are looking for a lightweight battery that cycles well and lasts for a very long time, and you don't mind paying some extra money, consider lithium deep cycle group 24/27 battery.


Long Story Short: If your battery compartment can accept group 27 battery, and if your charging system can properly charge such battery, and you don't mind having a somewhat heavier battery, group 27 batteries have a larger capacity, longer RC, and generally support stronger discharge currents.

Before ordering a new group 24 or group 27 battery, be sure that it is the right battery for your intended application and that it matches your needs regarding size, terminal types and orientation, capacity, CCA/MCA rating, RC rating, and similar.

And whatever You do, stay safe - these batteries are smaller than the group 31 or similar batteries, but they store plenty of energy and can release it instantly ...

Amazon Search:

- Group 27 AGM Battery

- Group 27 Lithium Battery

- 15 Amps AGM Battery Charger

Note: Amazon links open in the new windows, feel free to check them for the most up-to-date offers and prices.