A Group 27 battery typically measures 12.4 x 6.8 x 8.9 inches (LxWxH) and weighs 45-60 lbs. It is a mid-sized battery used in marine, RV, and automotive applications, balancing power and compactness. Terminal types (top/post) and capacity (75-115 Ah) vary by brand. Always check manufacturer specs for exact dimensions before installation.
What Is a Group Size 24 Battery?
How Does a Group 27 Battery Compare to Other Battery Sizes?
Group 27 batteries are larger than Group 24 (10.3″ L) but smaller than Group 31 (13″ L). They provide higher reserve capacity (140-190 minutes) than Group 24, making them ideal for prolonged use in boats or RVs. Unlike compact batteries like Group 35, Group 27 prioritizes capacity over space efficiency, often featuring thicker lead plates for durability.
When comparing energy density, Group 27 offers 15% more amp-hour capacity than Group 24 while maintaining a manageable footprint. This makes it particularly popular for dual-purpose applications requiring both starting power and deep cycling. For example, a typical Group 27 marine battery provides 800 MCA (marine cranking amps) compared to Group 24’s 650 MCA, while maintaining 30% longer runtime for accessories like fishfinders or bilge pumps.
Top 5 best-selling Group 14 batteries under $100
| Product Name | Short Description | Amazon URL |
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Weize YTX14 BS ATV Battery  |
Maintenance-free sealed AGM battery, compatible with various motorcycles and powersports vehicles. | View on Amazon |
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UPLUS ATV Battery YTX14AH-BS  |
Sealed AGM battery designed for ATVs, UTVs, and motorcycles, offering reliable performance. | View on Amazon |
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Weize YTX20L-BS High Performance  |
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Mighty Max Battery ML-U1-CCAHR  |
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Battanux 12N9-BS Motorcycle Battery  |
Sealed SLA/AGM battery for ATVs and motorcycles, maintenance-free with advanced technology. | View on Amazon |
| Battery Group | Length (in) | Reserve Capacity | Common Use |
|---|---|---|---|
| 24 | 10.3 | 120-150 min | Passenger vehicles |
| 27 | 12.4 | 160-190 min | RVs/Marine |
| 31 | 13 | 200-220 min | Commercial equipment |
What Are the Common Applications for a Group 27 Battery?
Group 27 batteries power marine engines, trolling motors, RVs, and diesel trucks. Their 750-1,000 CCA (cold cranking amps) supports heavy-duty starters, while deep-cycle variants handle auxiliary systems like solar panels. They’re also used in off-grid setups due to their 180-220Ah capacity, which outperforms smaller automotive batteries in sustained energy delivery.
How Much Does a Group 27 Battery Weigh?
A standard Group 27 battery weighs 45-60 lbs, depending on construction. Flooded lead-acid models are heavier (55-60 lbs) due to electrolyte fluid, while AGM variants are lighter (45-52 lbs). Lithium-ion Group 27 batteries weigh 25-35 lbs but cost 3x more. Weight impacts portability and vehicle payload capacity—critical for marine and RV use.
What Terminal Types Do Group 27 Batteries Use?
Most Group 27 batteries feature SAE post terminals (0.75″ top-mounted studs). Marine versions may include dual terminals: SAE posts and threaded studs (3/8″-16 UNC) for trolling motor connections. Terminal placement (left/right positive) varies; Odyssey and Optima models often reverse configurations. Always verify polarity alignment to avoid installation errors.
How Long Does a Group 27 Battery Last?
Flooded Group 27 batteries last 3-5 years, AGM 4-7 years, and lithium-ion 10+ years. Lifespan depends on discharge depth—avoid draining below 50% for lead-acid. Regular maintenance (cleaning terminals, equalizing charges) extends longevity. Marine environments reduce lifespan by 20% due to vibration and humidity, making AGM or gel cells preferable.
Environmental factors significantly impact battery durability. In extreme temperatures, capacity can decrease by up to 40%. For optimal performance in harsh conditions, consider these maintenance practices:
- Monthly terminal cleaning with baking soda solution
- Using insulated battery blankets in freezing climates
- Installing vibration-resistant mounting systems in boats
| Battery Type | Average Cycles | Temperature Tolerance |
|---|---|---|
| Flooded | 300-500 | 32°F to 100°F |
| AGM | 600-800 | -4°F to 122°F |
| Lithium | 3,000+ | -22°F to 140°F |
Can a Group 27 Battery Be Used as a Deep-Cycle Battery?
Yes, dual-purpose Group 27 batteries (e.g., Odyssey 27M-PC2150) combine starting (900 CCA) and deep-cycle (135Ah) capabilities. Pure deep-cycle models (like Trojan 27TMX) sacrifice CCA for 20% longer cycle life. For daily deep discharging (e.g., solar storage), lithium variants outperform lead-acid with 3,000+ cycles at 100% depth of discharge.
Expert Views
“Group 27 remains the gold standard for marine auxiliary power due to its balance of size and capacity. Recent shifts toward lithium are notable, but AGM still dominates 70% of the market for its cost-effectiveness.” — Marine Power Systems Engineer
Conclusion
Group 27 batteries offer versatile power solutions with standardized dimensions adaptable to diverse applications. Understanding their technical specs ensures optimal performance, whether for engine starting or deep-cycle energy storage. Advances in AGM and lithium technology continue to expand their usability in demanding environments.
FAQs
- Is Group 27 the same as 27F?
- No. Group 27F denotes reversed terminals (positive on right side), commonly used in Japanese vehicles. Always verify terminal layout compatibility.
- Can I replace a Group 24 with a Group 27?
- Yes, if the battery tray accommodates the larger size. Group 27 provides 20-30% more capacity but requires 2″ additional length space.
- Are Group 27 batteries sealed?
- AGM and gel Group 27 batteries are sealed and maintenance-free. Flooded types require periodic water topping and venting.