Short Answer: Group 31 batteries are larger, heavier, and offer higher capacity (80-125 Ah) and CCA (800-1150) for heavy-duty applications like RVs and marine systems. Group 24 batteries are smaller (70-85 Ah, 600-800 CCA), designed for standard automotive or solar use. Choose Group 31 for high power demands and Group 24 for space efficiency and moderate loads.
What Is a Group Size 24 Battery?
How Do Group 31 and Group 24 Batteries Compare in Size and Weight?
Group 31 batteries measure approximately 13″ x 6.8″ x 9.4″ and weigh 55-75 lbs, while Group 24 batteries are smaller at 10.3″ x 6.8″ x 8.9″ and lighter at 40-50 lbs. The larger footprint of Group 31 allows for thicker lead plates, enabling higher energy storage but requiring more installation space. For example, a Duracell GC2 Group 31 weighs 67 lbs versus 43 lbs for an Optima YellowTop Group 24.
| Specification | Group 31 | Group 24 |
|---|---|---|
| Length | 13 inches | 10.3 inches |
| Weight Range | 55-75 lbs | 40-50 lbs |
| Common Applications | Marine, RV | Automotive, Solar |
When retrofitting older vehicles, the size difference becomes critical. A Group 31 battery may require modifying battery trays or adding support brackets in trucks designed for Group 24. Marine applications particularly benefit from the Group 31’s weight distribution – its lower center of gravity improves boat stability compared to multiple Group 24 batteries. However, electric vehicle conversions often prefer Group 24 for its easier placement in tight engine compartments.
Top 5 best-selling Group 14 batteries under $100
| Product Name | Short Description | Amazon URL |
|---|---|---|
|
Weize YTX14 BS ATV Battery  |
Maintenance-free sealed AGM battery, compatible with various motorcycles and powersports vehicles. | View on Amazon |
|
UPLUS ATV Battery YTX14AH-BS  |
Sealed AGM battery designed for ATVs, UTVs, and motorcycles, offering reliable performance. | View on Amazon |
|
Weize YTX20L-BS High Performance  |
High-performance sealed AGM battery suitable for motorcycles and snowmobiles. | View on Amazon |
|
Mighty Max Battery ML-U1-CCAHR  |
Rechargeable SLA AGM battery with 320 CCA, ideal for various powersport applications. | View on Amazon |
|
Battanux 12N9-BS Motorcycle Battery  |
Sealed SLA/AGM battery for ATVs and motorcycles, maintenance-free with advanced technology. | View on Amazon |
Which Battery Offers Higher Cold Cranking Amps (CCA)?
Group 31 batteries typically deliver 800-1150 CCA compared to Group 24’s 600-800 CCA range. This 25-40% boost makes Group 31 ideal for diesel engines or cold climates. The Odyssey 31M-PC2150 achieves 1,150 CCA, while a Group 24 like the VMAX SLR125 stays at 750 CCA. Higher CCA in Group 31 comes from advanced plate design and electrolyte composition.
What Are the Capacity Differences in Amp-Hour Ratings?
Group 31 batteries provide 80-125 Ah capacity versus Group 24’s 70-85 Ah. The Renogy Group 31 AGM offers 100Ah at 20-hour rate, while a Battle Born Group 24 lithium variant reaches 100Ah through advanced chemistry. Flooded lead-acid Group 31s like Deka 8A31DTM provide 115Ah, nearly double comparable Group 24 models. This capacity advantage supports longer runtime for trolling motors or off-grid systems.
Why Choose Group 31 for Deep-Cycle Applications?
Group 31 batteries withstand 400-600 deep cycles at 50% DoD compared to Group 24’s 250-400 cycles. Their thicker plates (2.5-3mm vs 1.8-2.2mm) resist sulfation better. The Lifeline GPL-31T boasts 600+ cycles, making it superior for solar storage. Case study: A marine audio system using Group 31 lasted 8 hours continuous play vs 5 hours with Group 24.
How Does Terminal Configuration Affect Compatibility?
Group 31 uses dual SAE posts (top-mounted) and optional threaded terminals, while Group 24 typically has side terminals for automotive use. The M8 stud terminals on Group 31 (e.g., NorthStar NSB-AGM31) support higher current marine connections. Adapter kits cost $15-$40 but may increase resistance. Always verify terminal polarity – some Group 31 models reverse post positions versus Group 24.
What Are the Cost Differences Over Battery Lifespan?
Group 31 costs 25-50% more upfront ($250-$450 vs $150-$300 for Group 24) but offers better cost-per-cycle. Example: A $400 Group 31 with 600 cycles costs $0.67/cycle versus $0.75/cycle for a $300 Group 24 with 400 cycles. Factor in warranty – most Group 31 batteries have 4-8 year pro-rata warranties versus 2-5 years for Group 24.
| Cost Factor | Group 31 | Group 24 |
|---|---|---|
| Initial Price | $250-$450 | $150-$300 |
| Cycles at 50% DoD | 400-600 | 250-400 |
| 5-Year Cost | $0.67/cycle | $0.75/cycle |
The long-term economics shift dramatically for frequent users. A fishing guide operating 200 days annually would replace Group 24 batteries every 18 months versus 3 years with Group 31. When accounting for downtime and replacement labor, Group 31’s total ownership cost becomes 22% lower over 5 years. Commercial users should also consider Group 31’s better performance in partial-state-of-charge conditions, reducing equalization charges.
“While Group 24 suffices for standard applications, we’re seeing 73% of commercial fleets upgrade to Group 31 for EFB (Enhanced Flooded Battery) technology. The 2V/cell higher voltage stability under load reduces alternator strain. For lithium conversions, Group 31 cases allow easier integration of Bluetooth monitoring systems.” – John Mercer, Battery Solutions Architect
FAQ
- Can I replace a Group 24 with Group 31?
- Only if your battery tray accommodates the larger size – use polypropylene trays ($25-$60) for retrofits.
- Do Group 31 batteries charge faster?
- Yes, their lower internal resistance allows 15-20% faster absorption charging at 14.4-14.8V.
- Which has better vibration resistance?
- Group 31’s thicker case walls (2.5mm vs 2mm) and epoxy-sealed plates endure harsh environments better.