Group 27 Batteries

The BCI Group 27 battery is a heavy-duty power solution commonly found in larger vehicles, RV house banks, and marine applications. Offering a larger capacity and higher reserve power than the standard Group 24, it is the ideal choice for demanding electrical systems.

At Battery Mart, we offer premium Group 27 replacements designed to handle deep discharges and high-torque starting. Whether you need the American-made reliability of the Marathon AGM, the industry-leading pure lead power of the Odyssey ODX-AGM27, or the revolutionary weight savings of Antigravity Lithium, our selection ensures you have the power you need when it matters most.

The BCI Group 27 battery is a heavy-duty power solution commonly found in larger vehicles, RV house banks, and marine applications. Offering a larger capacity and higher reserve power than the standard Group 24, it is the ideal choice for demanding electrical systems.

At Battery Mart, we offer premium Group 27 replacements designed to handle deep discharges and high-torque starting. Whether you need the American-made reliability of the Marathon AGM, the industry-leading pure lead power of the Odyssey ODX-AGM27, or the revolutionary weight savings of Antigravity Lithium, our selection ensures you have the power you need when it matters most.

Marathon 8A27 Group 27 AGM Battery [12V, 92Ah]
Item #: 8A27  |    

Marathon 8A27 Group 27 AGM Battery [12V, 92Ah]

Special Order: Ships in 1 Week
Made in USA MADE IN USA

Marathon 8A27 Group 27 AGM Battery [12V, 92Ah]

Item #: 8A27   |  Special Order: Ships in 1 Week
 
Voltage: 12 Volt / 92 Ah / 580 CCA
• AGM
• Dimensions: 12.99" / 6.73" / 8.62"
• Weight: 65.00 lbs
• Warranty: 2 Year Factory Direct
Price:
$315.95
Price: $315.95
QTY:
ODYSSEY ODX-AGM27 Extreme AGM Battery
Item #: ODX-AGM27  |    

ODYSSEY ODX-AGM27 Extreme AGM Battery

ODYSSEY ODX-AGM27 Extreme AGM Battery

Item #: ODX-AGM27
 
Voltage: 12 Volt / 92 Ah / 930 CCA
• AGM
• Dimensions: 12.5" / 6.8" / 8.2"
• Weight: 72.00 lbs
• Warranty: 2-4 Year (Warranty Info)
MSRP: $519.99
Price:
See Best Price in Cart
QTY:
Antigravity Group 27 / 27F Lithium Car Battery (40Ah)
Item #: AG-27-40-RS  |    

Antigravity Group 27 / 27F Lithium Car Battery (40Ah)

Antigravity Group 27 / 27F Lithium Car Battery (40Ah)

Item #: AG-27-40-RS
 
Voltage: 12.8 Volt / 40 Ah / 1500 CCA
• LiFePO4
• Dimensions: 12" / 6.85" / 8.75"
• Weight: 16.60 lbs
• Warranty: 5 Year Factory Direct - Warranty Info (PDF)
Price:
$949.99
Price: $949.99
QTY:

Understanding Group Size 27 Battery Specifications

When upgrading to or replacing a Group 27 battery, it is important to account for its larger physical footprint compared to standard automotive sizes. The Group 27 is longer and often heavier than a Group 24 or 25, providing a significant boost in Amp Hour (Ah) capacity and Reserve Capacity (RC).

Group 27 Battery Dimensions

Standard Group 27 dimensions are approximately:

  • Length: 12.06 inches (306 mm)
  • Width: 6.81 inches (173 mm)
  • Height: 8.88 inches (225 mm)

High-Performance Technologies for Group 27 Applications

Our inventory features specialized chemistries to meet the needs of modern high-draw vehicles and auxiliary power systems:

  • Marathon 8A27 AGM: This premium AGM battery is built to the same rigorous specifications as the renowned Deka 8A27. It provides a spill-proof, maintenance-free design with excellent vibration resistance, making it a dependable choice for both starting and moderate cycling duties.
  • Odyssey ODX-AGM27 (Extreme Series): Utilizing Thin Plate Pure Lead (TPPL) technology, the Odyssey Extreme 27 offers massive cranking power and deep-cycle capabilities in one unit. It is engineered to last up to three times longer than conventional batteries and is perfect for vehicles with excessive auxiliary loads.
  • Antigravity AG-27-40-RS Lithium: Representing the pinnacle of battery technology, this LiFePO4 battery offers 40Ah of usable power while weighing roughly 70% less than a lead-acid equivalent. It includes the "RE-START" feature, allowing you to wirelessly jump-start your vehicle if the battery is ever over-discharged.

Why Choose AGM or Lithium for Group 27?

Because Group 27 batteries are often used in RVs, boats, and heavy-duty trucks, durability is paramount.

  • No Maintenance: All our Group 27 options are sealed. You never have to check water levels or deal with acid corrosion on your terminals.
  • Superior Cycling: Our AGM and Lithium options can be discharged deeper and more frequently than standard flooded batteries without losing capacity.
  • Mounting Flexibility: The sealed design of these batteries allows them to be mounted in various orientations (except upside down) without the risk of leaks.

Finding the Right Fit

Choosing between these three premium options depends on your goals. For the best value in a high-quality AGM, the Marathon is an excellent choice. For maximum durability and pure lead performance, choose Odyssey. If you want to shed significant weight while adding smart safety features, the Antigravity Lithium is the ultimate upgrade for your Group 27 application.