Odyssey Extreme Series Group 31 Battery

Quick Facts

Manufacturer: EnerSys
Brand: Odyssey Battery
Product Series: Extreme Series
Current Model: ODX-AGM31
Former Model: 31-PC2150S
Product Type: Dual-purpose commercial AGM battery
Battery Group: BCI Group 31
Nominal Voltage: 12 volts
Battery Technology: Thin Plate Pure Lead absorbed glass mat
Cold-Cranking Amps: 1,150 CCA
Five-Second Pulse Cranking: 2,150 amps
20-Hour Capacity: 103 amp-hours
Reserve Capacity: 220 minutes
Published Weight: Approximately 77.8 pounds
Primary Applications: Commercial trucks, buses, vocational vehicles, emergency equipment, marine equipment, generators, and off-highway machinery
Primary Benefit: Combines high engine-cranking output with substantial reserve and deep-cycle capability

Overview

The Odyssey Extreme Series Group 31 Battery is a premium dual-purpose battery manufactured by EnerSys. It combines powerful engine-starting capability with reserve capacity and cycling performance for commercial vehicles and equipment carrying substantial electrical loads.

The ODX-AGM31 uses Thin Plate Pure Lead technology. Its numerous thin plates provide substantial surface area within the Group 31 case, helping the battery deliver high cranking current and efficient energy storage.

Sealed absorbed glass mat construction immobilizes the electrolyte and eliminates routine water addition. Several Group 31 terminal and polarity configurations are available within the Odyssey Extreme Series, so the exact model must be matched to the vehicle.

Key Characteristics

Commercial Group 31 battery
Thin Plate Pure Lead construction
Sealed absorbed glass mat technology
Dual-purpose starting and deep-cycle performance
High five-second pulse-cranking output
Substantial cold-cranking capability
High reserve capacity
Maintenance-free operation under normal conditions
Spill-resistant electrolyte containment
Designed to resist vibration and high-impact shock
Can be installed on its side where approved
Multiple terminal and polarity configurations
Designed for demanding temperatures and service conditions

Major Components

Heavy-duty battery case
Sealed top cover
Thin pure-lead positive plates
Thin pure-lead negative plates
Absorbed glass mat separators
Immobilized electrolyte
Internal cell connectors
Positive terminal
Negative terminal
Pressure-relief valves
Cell partitions
Terminal seals
Internal vibration-resistant plate structure
Carry handles where equipped

Product Type and Construction

The ODX-AGM31 is a sealed valve-regulated lead-acid battery using absorbed glass mat and Thin Plate Pure Lead technologies. Fiberglass separators hold the electrolyte against the plates instead of allowing liquid electrolyte to move freely inside the case.

Using numerous thin plates increases the active plate surface area available for current transfer. The design supports high starting output while retaining the ability to supply repeated cycling and reserve power.

How the Electrical Component or System Works

The battery stores energy through a reversible chemical reaction between its lead plates and sulfuric-acid electrolyte. During discharge, the reaction produces direct-current electricity for the starter and other vehicle equipment.

When the alternator or an approved charger supplies the correct voltage, the reaction reverses and restores the battery’s state of charge. Its valve-regulated construction supports internal gas recombination during normal charging.

Position and Function Within the Vehicle

The battery may be installed in a chassis-mounted battery box, under-cab compartment, engine compartment, auxiliary-power enclosure, or another approved location. Commercial vehicles may use several Group 31 batteries in one bank.

Its functions include supplying engine-starting current, stabilizing system voltage, powering equipment when the engine is off, supporting high-demand accessories, and storing energy produced by the alternator.

Common Specifications

Current Model: ODX-AGM31
Former Model: 31-PC2150S
BCI Group Size: Group 31
Battery Type: Dual-purpose TPPL AGM battery
Nominal Voltage: 12 volts
Five-Second Pulse Cranking: 2,150 amps
Cold-Cranking Amps: 1,150 amps
Hot-Cranking Amps: 1,545 amps
Marine-Cranking Amps: 1,370 amps
20-Hour Capacity: 103 amp-hours
10-Hour Capacity: 98 amp-hours
Reserve Capacity: 220 minutes
Maximum Length: 13 inches
Maximum Width: 6.8 inches
Maximum Total Height: 9.5 inches
Published Weight: 77.8 pounds
Terminals: 3/8-16-inch studs on the ODX-AGM31
Maximum Stud Torque: 200 inch-pounds
Published Internal Resistance: Approximately 2.2 milliohms

Operating Capacity and Performance

The ODX-AGM31 is rated to deliver a five-second pulse of 2,150 amps and 1,150 cold-cranking amps. Its 103-amp-hour capacity and 220-minute reserve rating also allow it to support engine-off electrical loads and cycling applications.

EnerSys states that the broader Extreme Series can provide up to 400 charge-and-discharge cycles at 80 percent depth of discharge under specified conditions. Actual battery performance and life depend on application, charging, temperature, and discharge history.

Installation Position and System Function

The battery must be installed in a tray or enclosure capable of supporting its dimensions and approximately 77.8-pound weight. The hold-down should secure the battery firmly without deforming the case.

The sealed AGM design permits approved side installation, but the battery should not be installed upside down. Orientation must follow EnerSys and vehicle-manufacturer instructions.

System Voltage and Electrical Architecture

A single ODX-AGM31 supplies nominal 12-volt power. Multiple batteries may be connected in parallel to increase current and reserve capacity while retaining a 12-volt architecture.

Approved series connections can create a 24-volt system. Batteries used together should match in model, technology, age, capacity, condition, and state of charge.

Electrical Input, Output, and Power Function

The battery receives direct-current charging energy from the vehicle alternator or an approved external charger. During discharge, it supplies direct-current power to the starter, vehicle electronics, lighting, safety systems, hotel loads, and auxiliary equipment.

Its low internal resistance helps support high-current engine cranking and efficient current delivery. Available voltage still decreases as the battery discharges or electrical demand rises.

Voltage, Current, and Electrical Load Management

The battery bank must provide enough current to operate the starter while maintaining adequate voltage for engine controllers, fuel systems, starter relays, and other electronics.

Although the Odyssey Extreme Series supports deep cycling, engine-off loads should still be managed to preserve starting reserve and avoid unnecessary battery wear.

Starting, Cycling, and Reserve-Power Function

The ODX-AGM31 is designed to perform both starting and cycling functions. It can deliver the short, high-current pulse needed for engine cranking and provide sustained reserve power for accessories and auxiliary equipment.

This dual-purpose capability makes it suitable for trucks and equipment that combine demanding starting requirements with substantial electrical use while the engine is off.

Cold-Cranking and Reserve Capacity

The 1,150-CCA rating represents cold-starting capability under standardized test conditions. The five-second pulse rating of 2,150 amps describes short-duration high-current performance.

The published reserve capacity of 220 minutes describes how long a fully charged battery can support a standardized load before reaching the specified cutoff voltage. Real operating time depends on actual load, temperature, and battery condition.

Thin Plate Pure Lead Design

Odyssey Extreme batteries use plates made from 99 percent pure lead. The plates are manufactured thinner than those in many conventional batteries, allowing more plates to fit inside the case.

The additional plate surface area supports high current output, low internal resistance, efficient recharge acceptance, and substantial stored-energy capacity.

Internal Components and Electrical Design

Each battery cell contains tightly packed positive and negative pure-lead plates separated by absorbed glass mat material. Six cells are connected in series to produce nominal 12-volt output.

Valve regulation supports internal gas recombination during normal operation. The sealed plate packs and internal supports help resist shock and vibration.

Materials and Component Construction

The battery uses thin pure-lead plates, fiberglass separators, sulfuric-acid electrolyte, internal lead connections, heavy-duty case materials, sealed terminals, and pressure-relief valves.

The ODX-AGM31 does not use a metal jacket. Temperature limits and physical protection must therefore be based on the non-metal-jacket specification for the exact model.

Wiring, Terminals, Connectors, and Grounding

The standard ODX-AGM31 uses 3/8-16-inch stud terminals. Cable lugs must match the studs and provide full, clean contact without placing mechanical strain on the terminal.

EnerSys publishes a maximum stud torque of 200 inch-pounds for this model. The applicable installation instructions should be checked before tightening because excessive torque can damage the terminal or case.

Circuit Protection and Electrical Safety

The battery can release extremely high current during a short circuit. Cables must be insulated, supported, and protected from abrasion, crushing, heat, and unintended contact with grounded components.

Battery disconnect switches, fuses, circuit breakers, and distribution equipment should match the vehicle architecture and maximum expected current.

Controls, Monitoring, and Diagnostics

Battery condition may be monitored through vehicle voltage displays, battery sensors, low-voltage disconnects, telematics systems, external testers, or the Odyssey Connect monitoring system where installed.

Useful diagnostic information includes open-circuit voltage, state of charge, conductance, available cranking capacity, charging voltage, parasitic current, cable voltage drop, temperature, and battery-bank balance.

Electronic Controls and Driver-Assistance Integration

The battery supports engine, transmission, braking, steering, lighting, telematics, safety, and driver-assistance electronics according to the vehicle’s electrical architecture.

Low battery voltage can cause communication faults, warning messages, module resets, failed startup checks, or temporary loss of electronic functions.

Power Demand, Capacity, and Energy Management

The number of batteries required depends on starter demand, system voltage, engine-off electrical loads, minimum reserve requirements, operating temperature, charging-system capacity, and available recharge time.

Vehicles using sleeper HVAC, liftgates, emergency lighting, communications equipment, refrigeration controls, or other auxiliary systems should undergo an electrical-load analysis before the battery bank is specified.

Charging Efficiency and Energy Recovery

Thin Plate Pure Lead construction supports efficient charge acceptance. However, the alternator or external charger must provide a voltage profile approved for Odyssey AGM batteries.

Chronic undercharging can cause sulfation and lost capacity. Excessive charging voltage can create heat, venting, electrolyte loss, and permanent damage.

Heat, Efficiency, and Electrical Loss Management

The non-metal-jacket Extreme Series is rated for an operating-temperature range beginning at approximately -40°F and extending to approximately 140°F. Charging requirements and available capacity still change with temperature.

Loose terminals, damaged cables, excessive charging voltage, high-current cycling, and inadequate ventilation can generate heat and shorten battery life.

Environmental Sealing and Contamination Protection

The sealed AGM design immobilizes the electrolyte and prevents normal acid spills, even if the battery is placed on its side in an approved installation. Pressure-relief valves provide controlled venting under abnormal internal pressure.

The battery should still be protected from impact, puncture, fire, excessive heat, conductive debris, damaged terminals, and direct high-pressure washing.

Duty Cycle and Operating Conditions

The ODX-AGM31 is suitable for engine starting, repeated cycling, high accessory demand, and applications exposed to shock or vibration. It is used in road vehicles, marine equipment, generators, emergency equipment, and off-highway machinery.

Actual cycle life depends on discharge depth, recharge time, charging voltage, temperature, storage conditions, and the frequency of high-current operation.

Mounting and Installation

The battery tray and enclosure must support the battery’s dimensions and approximately 77.8-pound weight. Hold-down hardware must secure the battery without cracking or distorting the case.

The installation must provide correct terminal orientation, cable clearance, ventilation, service access, and protection from excessive heat and physical damage.

Wiring, Grounding, and Installation Requirements

Cables must be connected with correct polarity and routed without placing force on the terminal studs. Parallel connections should promote balanced current flow across the battery bank.

Series-connected batteries must follow the correct sequence to produce the intended voltage. Reversed polarity can damage the battery, alternator, starter, controllers, and connected equipment.

Vehicle and Electrical-System Compatibility

Compatibility depends on group size, nominal voltage, starting requirements, reserve capacity, amp-hour demand, terminal configuration, polarity, battery-box dimensions, hold-down design, charging voltage, and operating environment.

The Group 31 designation confirms general dimensions but does not guarantee correct terminals, polarity, height, performance, or charging compatibility.

Battery and Charging-System Compatibility

The alternator, voltage regulator, battery isolator, inverter-charger, and external charger must be compatible with TPPL AGM technology. EnerSys charging instructions should be followed when selecting voltage and current settings.

When multiple batteries share a bank, each battery should be tested before replacement. Mixing batteries with different technologies, ages, capacities, or conditions can create imbalance.

Related Component and System Compatibility

Heavy-duty starters
High-output alternators
Voltage regulators
Battery cables and terminals
Battery disconnect switches
Battery isolators
Low-voltage disconnects
Power-distribution modules
Inverters and converters
AGM-compatible chargers
Auxiliary power systems
Battery-monitoring and telematics equipment

Common Applications

Heavy-duty highway tractors
Vocational trucks
Transit buses
Motor coaches
Emergency vehicles
Utility trucks
Construction equipment
Mining equipment
Agricultural machinery
Marine equipment
Generator systems
Off-highway equipment
Vehicles with sleeper electrical loads
Vehicles requiring starting and deep-cycle capability

Advantages

1,150 cold-cranking amps
2,150-amp five-second pulse capability
220 minutes of reserve capacity
Dual-purpose starting and cycling performance
Thin Plate Pure Lead construction
Low internal resistance
Efficient charge acceptance
Maintenance-free operation
Spill-resistant AGM construction
High vibration and shock resistance
Approved side installation capability
Multiple Group 31 configurations
Suitable for demanding commercial electrical systems

Limitations or Considerations

Higher initial cost than many conventional flooded batteries
Requires an AGM-compatible charging system
Weighs approximately 77.8 pounds
Terminal configuration must match the vehicle
Charging voltage must remain within approved limits
Can be damaged by chronic overcharging
Repeated deep discharge still affects service life
Multiple-battery banks require compatible batteries
The sealed case should not be opened
Upside-down installation is not approved
A new battery cannot correct alternator or wiring problems
Physical dimensions must be verified despite the Group 31 designation

Driver and Operator Experience

A fully charged ODX-AGM31 should provide strong engine cranking and stable electrical-system voltage. Its reserve capacity can support substantial accessory use when the engine is off.

Drivers should report slow cranking, repeated low-voltage warnings, control-module resets, dimming lights, hot terminals, unusual odors, case swelling, or repeated jump-start requirements.

Controls, Indicators, and Driver Feedback

Battery condition may be communicated through a voltage display, low-voltage warning, battery-management system, telematics alert, Odyssey Connect monitor, or changes in engine-cranking performance.

Dashboard voltage alone does not confirm battery health. State of charge, available cranking capacity, and battery-bank balance require proper diagnostic testing.

Common Electrical Tests and Diagnostic Information

Open-circuit voltage test
Battery conductance test
AGM-compatible load test
Cranking-voltage test
State-of-charge measurement
Charging-voltage test
Alternator output test
Positive-circuit voltage-drop test
Ground-circuit voltage-drop test
Parasitic-current test
Individual battery comparison
Battery-bank balance test
Terminal-temperature inspection

Inspection and Wear Points

Battery case
Top cover and case seams
Positive and negative terminal studs
Terminal seals
Cable lugs
Battery cables
Ground connections
Insulating terminal covers
Hold-down hardware
Battery tray
Compartment ventilation
Heat shields
Evidence of swelling, leakage, corrosion, or impact damage

Cooling, Ventilation, and Environmental Requirements

The battery should be installed in a ventilated location protected from excessive heat, direct flame, physical damage, conductive contamination, and standing water.

Valve-regulated batteries can release gas under abnormal charging or failure conditions. Battery compartments should prevent gas accumulation near ignition sources.

Component Service Life and Replacement

EnerSys publishes an eight- to twelve-year design-life range and a three- to ten-year service-life range for the broader Extreme Series. Actual Group 31 life depends on temperature, cycling, charging, storage, vibration, and application.

The sealed battery is not normally rebuilt during vehicle service. A battery that fails approved testing, develops physical damage, leaks, swells, or cannot retain charge should be replaced and recycled appropriately.

Maintenance and Ownership Notes

The sealed battery does not require routine water addition. Maintenance should focus on clean terminals, secure connections, undamaged cables, correct hold-down tension, proper charging voltage, and periodic battery testing.

Vehicles stored for extended periods may require an Odyssey-compatible maintenance charger or battery disconnect to prevent discharge from parasitic electrical loads.

Common Electrical-System Problems

Slow engine cranking: A discharged battery, internal deterioration, loose terminals, cable resistance, starter problems, cold temperature, or engine resistance may reduce cranking speed.
Battery repeatedly discharges: Parasitic loads, insufficient alternator output, short operating cycles, excessive engine-off accessory use, or an internally damaged battery may be responsible.
Low charging voltage: Alternator faults, belt slip, cable voltage drop, poor grounds, regulator problems, or excessive electrical demand may prevent full charging.
Overcharging: Incorrect charger settings, regulator failure, wiring faults, or temperature-compensation problems can overheat and damage the battery.
Swollen battery case: Overcharging, excessive temperature, freezing after severe discharge, or internal failure may deform the case.
Hot terminals: Loose hardware, corrosion, damaged lugs, undersized cables, or excessive current can generate heat.
Uneven battery-bank performance: Mismatched batteries, unbalanced cables, different states of charge, internal failure, or unequal circuit resistance can cause imbalance.
Reduced reserve capacity: Battery aging, chronic undercharging, excessive heat, repeated deep cycling, or increased electrical demand may reduce operating time.

Safety and Service Precautions

Wear suitable eye and hand protection when handling, testing, or charging the battery. Remove jewelry and prevent tools from contacting both terminals or a positive terminal and grounded vehicle structure.

Follow the vehicle manufacturer’s disconnection and reconnection sequence. Use lifting procedures appropriate for the battery’s approximately 77.8-pound weight. Never open the sealed case, add water, expose the battery to flame, or use an incompatible charger.

Identification Information

Identification information is printed on the battery label or case. Record the complete Odyssey part number before ordering a replacement.

Odyssey brand name
Extreme Series designation
ODX-AGM31 current model
31-PC2150S former model
BCI Group 31 designation
Nominal voltage
Cold-cranking-amp rating
Pulse-cranking rating
Reserve-capacity rating
Amp-hour capacity
Terminal configuration
Terminal polarity and layout
Manufacturing date code
Vehicle battery-bank configuration

Buying Considerations

Confirm the ODX-AGM31 model number
Check whether the old 31-PC2150S number is being replaced
Verify the Group 31 dimensions
Match the 12-volt electrical system
Confirm starting and reserve-capacity requirements
Match the terminal configuration
Verify terminal polarity and cable reach
Confirm battery-box and hold-down capacity
Account for the 77.8-pound battery weight
Verify AGM-compatible charging
Check every battery in a multi-battery bank
Review installation orientation
Confirm current warranty terms
Use a supplier that accepts the old battery for recycling

Variants and Configurations

ODX-AGM31 with stud terminals
ODX-AGM31A with SAE terminals
ODX-AGM31R with reversed stud-terminal layout
ODX-AGM31M with combined marine terminal arrangements
Single-battery installations
Parallel 12-volt battery banks
Series-connected 24-volt battery banks
Starting applications
Dual-purpose starting and cycling applications
Marine and specialized-equipment applications

Comparison to Similar Equipment

Compared with the Deka Intimidator AGM Group 31 Battery, both use sealed AGM construction and support starting and cycling duty. The Odyssey provides different cranking, capacity, terminal, weight, and charging specifications.

Compared with the Deka Flooded Group 31 Commercial Battery, the Odyssey offers spill-resistant construction, greater cycling capability, no water maintenance, and stronger published pulse performance. The flooded battery generally has a lower initial cost.

Compared with a lithium commercial battery, the Odyssey uses familiar lead-acid charging and recycling infrastructure. Lithium systems may weigh less and provide greater usable cycling capacity but require application-specific electronics and protection.

Best Fit For

Commercial vehicles requiring strong Group 31 starting power
Vehicles combining starting and cycling duty
High electrical-load commercial trucks
Vehicles operating sleeper or auxiliary equipment
Emergency and municipal vehicles
Equipment exposed to substantial vibration or shock
Applications requiring spill-resistant construction
Parallel commercial battery banks
Approved 24-volt series battery systems
Vehicles equipped with compatible AGM charging systems

Related Vehicle and Trailer Types

Heavy-duty trucks
Highway tractors
Vocational trucks
Transit buses
Motor coaches
Emergency vehicles
Utility trucks
Construction equipment
Mining equipment
Agricultural machinery
Marine equipment
Generator systems

Related Truck and Trailer Models

Related Electrical System Types

Related Electrical Products

Related Equipment Systems

Related Guides

Regulatory and Compliance Notes

Lead-acid batteries must be transported, handled, stored, serviced, and recycled according to applicable environmental, workplace-safety, fire, and hazardous-material requirements.

Battery replacement must preserve the vehicle manufacturer’s voltage, capacity, terminal, mounting, ventilation, and electrical-protection requirements. Used Odyssey batteries should be returned through an approved lead-acid battery recycling program.

Real World Operating Notes

A battery can show acceptable open-circuit voltage while lacking sufficient cranking capacity. Conductance, load, and cranking-voltage testing provide a more complete evaluation.

The ODX-AGM31’s high reserve capacity does not eliminate the need for adequate alternator output. If engine-idle electrical demand exceeds charging output, the battery bank will still discharge.

One weak or poorly connected battery can reduce the performance of the complete bank. Testing should include every battery and the cables joining them.

Frequently Asked Questions

What is the Odyssey Extreme Series Group 31 Battery?

It is a sealed Thin Plate Pure Lead AGM battery designed to provide high engine-starting power, substantial reserve capacity, and deep-cycle performance.

What is the current model number?

The stud-terminal model is identified as ODX-AGM31. It was formerly sold as the 31-PC2150S.

How many cold-cranking amps does it provide?

The ODX-AGM31 is rated at 1,150 cold-cranking amps.

What is its five-second pulse rating?

The published five-second pulse-cranking rating is 2,150 amps.

What is its reserve capacity?

The published reserve-capacity rating is 220 minutes under standardized test conditions.

Does it require water?

No. Its sealed AGM design does not require routine water addition and should not be opened.

Can the battery be installed on its side?

Odyssey Extreme AGM batteries can be installed on their side in approved applications. Upside-down installation is not recommended.

Can it be used for starting and auxiliary loads?

Yes. It is a dual-purpose battery designed to support high-current engine starting and repeated cycling or reserve-power demands.

Does it require a special charger?

An external charger should be compatible with Odyssey TPPL AGM batteries and use the voltage and current settings specified by EnerSys.

Can it replace any Group 31 battery?

No. Voltage, terminals, polarity, dimensions, weight, hold-downs, charging requirements, and vehicle specifications must all be verified.

How is the correct Group 31 configuration identified?

Use the complete Odyssey model number, terminal type, polarity, dimensions, voltage, cranking ratings, reserve capacity, and battery-bank requirements.

Availability and Where to Find

The Odyssey Extreme Series ODX-AGM31 may be available through Odyssey Battery distributors, EnerSys dealers, commercial-truck parts suppliers, battery specialists, fleet-maintenance suppliers, marine dealers, off-highway equipment suppliers, and selected automotive-parts retailers.

Availability depends on terminal configuration, polarity, distributor inventory, and current model-number transitions. Buyers should confirm whether they require the ODX-AGM31, ODX-AGM31A, ODX-AGM31R, or ODX-AGM31M before ordering.

Current specifications, charging information, warranty terms, installation instructions, and distributor assistance are available through the Odyssey Battery website.

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