10 Best Group 31 Battery Reviews

When you’re out on the water or camping off the grid, the last thing you want is a dead battery. Your group 31 battery is the heart of your power system, starting your engine and running your electronics, so choosing the right one can make or break your trip. Whether you need deep-cycle reserves for a trolling motor or cold-cranking amps to fire up a diesel, the options can feel overwhelming.

In this guide, we’ve tested and compared ten of the best group 31 batteries on the market, from rugged AGM workhorses to advanced lithium iron phosphate (LiFePO4) models with Bluetooth monitoring. We’ll break down each product’s strengths, ideal use cases, and key trade-offs so you can confidently pick the battery that fits your setup and budget.

Interstate Batteries Marine/RV Battery 12V 100Ah 825CCA – Dual Purpose Pure Lead AGM

Interstate’s 31M-AGM-A is a pure lead AGM battery that serves double duty as a starting and deep-cycle battery. With 825 cold cranking amps and 100Ah capacity, it’s built to handle marine and RV demands. The pure lead construction gives you two to three times longer service life than standard alloy AGM or flooded batteries, and it recharges faster so you can spend more time on the water.

You’ll appreciate the thick lead plates that allow deep discharges without damaging the battery, making it ideal for powering lights, pumps, and electronics while anchored. The battery is also sealed and spill-proof, so you can mount it in tight spaces without worrying about acid leaks. Interstate’s 70-year reputation for reliability adds peace of mind, and you can recycle the battery at any Interstate All Battery Center when it eventually wears out.

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• DUAL PURPOSE MARINE RV BATTERY: Interstate's marine dual-purpose AGM battery can serve as both your cranking battery to start the motor & power your trolling motor – whether the motor is on or off! Built "Interstate tough" to withstand the most rugged conditions so you can spend more time having fun & less time worrying about your battery
• 2X-3X MORE BATTERY LIFE: This pure, non-alloy lead battery puts the most advanced battery technology on your side. The expected service life lasts 2x longer than conventional alloy AGM batteries & 3x that of a conventional flooded battery. With faster recharging & more overall life than a conventional alloy AGM battery, this battery stays ready for your fishing weekends
• EXTREME DEEP-CYCLE POWER: This 2-in-1 pure lead AGM battery delivers high-cranking, extreme deep cycle power. It's designed to provide reliable force over an extended period to power your boat's motor & all its accessories (lights, televisions, appliances, water pumps & more). Not all marine batteries are the same – & this one exceeds the rest. Built with thick plates so the battery continuously discharges power so you can recharge it many times over – without decreasing its lifespan. To ensure you don’t lose power while on your next trip, our batteries have been thoroughly tested & provide Outrageously Dependable benefits to boat & RV owners
• MOST TRUSTWORTHY POWER SOURCE: For 70 years, Interstate Batteries purpose has been to deliver the most Outrageously Dependable source of power to the world. Our customers come first, so we strive to create a positive experience for all. We recycle more batteries than we sell; please return to an Interstate All Battery Center near you so we can continue recycling

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Weize BCI Group 31M Dual Purpose AGM Battery – 240RC 825CCA 12V 110AH

The Weize Group 31M is a sealed AGM battery that offers a strong balance of starting power and deep-cycle capacity. With 825CCA and 110Ah, it’s designed for marine and RV use where you need reliable cranking and steady power for accessories. The advanced AGM technology gives you low internal resistance, which means higher output and faster charging – up to five times faster than a standard flooded battery.

You’ll also get 20 times more vibration resistance than flooded batteries, a huge plus if you’re bouncing down rough roads or choppy waters. It’s nearly maintenance-free, so you won’t need to check water levels or clean corrosion. Just remember to charge it with a constant voltage of 14.4V and a max current of 21A, and avoid charging beyond 24 hours to maintain battery health.

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• [Dual Purpose]: The WEIZE BCI Group 31M is a dual purpose deep cycle sealed AGM marine and RV battery. It features an outstanding starting power and deep cycling capability for long-lasting power supply. Terminal： Left : Positive (+)-Red, Right: Negative (-)-Black.
• [High Performance]: Powered by advanced AGM technology, the WEIZE BCI Group 31M has a low internal resistance and high output power, offering a reliable power supply and a long battery life, 2x more cycle life than traditional flooded marine batteries.
• [Quick Charge]: The WEIZE BCI Group 31M features quick charging, which allows it to charge up to five times faster, saving time and increasing efficiency. Please use a constant voltage of 14.4± 0.1V and a max current of 21A to charge the battery until the current has no change for 2 to 3 hours， But the maximum charging time must not exceed 24 hours.
• [Low Maintenance]: Being almost maintenance-free, the WEIZE BCI Group 31M reduces surface corrosion, proves more durable, and performs well against vibrations, has 20x more vibration resistance than flooded batteries.
• [Safety]: With a leak proof design and the presence of specialized valves, the WEIZE BCI Group 31M battery is very safe to use, ensuring a longer battery life.

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Odyssey Battery ODX-AGM31 Extreme Series AGM Battery – 1150 CCA

Odyssey’s Extreme Series AGM31 is a powerhouse with 1150 cold cranking amps and a pulse hot cranking amps rating of 2150. It’s built for maximum starting performance, even in extreme cold or heat. The reserve capacity of 205 minutes means you can run electronics for hours after the engine is off, making it a great choice for boats, RVs, and heavy-duty vehicles.

You’ll notice the rugged construction – pure lead plates and a compression-packed design deliver superior vibration resistance and a long service life. The battery is completely sealed and maintenance-free, and it can be mounted in any position except upside down. Odyssey batteries are known for their ability to recover from deep discharges, and with 1150CCA, you can start your engine with confidence every time.

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• Voltage: 12v – PHCA: 2150
• Cold Cranking Amps (CCA): 1150 – HCA: 1545
• Reserve Capacity in Minutes: 205
• Negative Terminal Location: Right Side
• Terminal: Group 31 with SS 3/8 inch threaded stud terminals and single external vent
• Fit type: Vehicle Specific

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Mighty Max Battery MM-G31 Start and Stop Car BCI Group 31 12V 100AH 900 CCA

The Mighty Max MM-G31 is designed for vehicles with start-stop systems, but it works great as a general-purpose group 31 battery. With 900 cold cranking amps and a 140-minute reserve capacity, it delivers strong, steady starts in any weather. The AGM design is sealed and spill-proof, so you can install it in tight spaces without worrying about acid leaks.

You’ll benefit from the high discharge output and deep discharge recovery, which means the battery can handle repeated cycling without losing performance. It’s also built to resist shock, vibration, and temperature extremes, making it a reliable companion for off-road adventures or marine use. The maintenance-free design saves you time, and the price is competitive for a 100Ah, 900CCA battery.

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• Fast Starting Power: This 12V 100Ah 900 CCA delivers strong, steady starts is ready for any weather in any season.
• Made to Last: With its 140-minute Reserve Capacity supports longer run times and a longer overall battery lifespan.
• All Power, No Mess AGM Design: Sealed and spill-proof, the MM-G31 is built with high discharge output and deep discharge recovery to keep power steady when it counts.
• Strength That Starts on the Inside: The rugged construction resists shock, vibration, and harsh conditions, delivering reliable performance across a wide range of temperatures and tough environments.
• Tested Tough & Certified Safe: Mighty Max batteries are built in an ISO-certified facility and meet CE standards for quality, safety, and reliability
• Rechargeable and Versatile: Mounts in multiple positions (excluding upside down) for flexible vehicle installation.
• Dimensions: Sized at 12.88 x 6.75 x 9.50 inches, ready to fit your ride with ease. Polarity is easy to spot, with the positive terminal on the left and the negative on the right.
• Included: Each battery includes mounting screws for quick, hassle-free installation.
• Not Included: Wire harness and mounting accessories are not included.
• 3 Year Warranty: Mighty Max strength, long-haul protection, and confidence that you’re powered to the max.

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Interstate Batteries Marine Deep Cycle Battery 31-AGM5 – 925CCA Pure Lead AGM

Interstate’s 31-AGM5 is a commercial-grade pure lead AGM battery with 925 cold cranking amps and a true deep-cycle design. It’s built for heavy-duty applications like auxiliary power units (APUs), starting engines, and running sensitive electronics on boats, RVs, and work trucks. The pure lead construction gives you 2-3 times longer service life than conventional flooded or alloy AGM batteries.

You’ll appreciate the thick plates that allow repeated deep discharges without capacity loss, ideal for powering trolling motors, fish finders, and audio systems all day. The battery is also built “Interstate tough” to withstand vibration and harsh marine conditions. While it’s not designed for automotive or mobility devices, it’s an outstanding choice for serious marine and commercial use where reliability is non-negotiable.

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• EXTREME DEEP-CYCLE POWER: This 2-in-1 pure lead AGM battery delivers high-cranking, extreme deep cycle power. It's designed to provide reliable force over an extended period to power your boat's motor & all of its accessories (appliances, trolling motor, audio systems, depth finders, fish locators, windlass). Not all marine batteries are the same – but this one exceeds the rest. Built with thick plates to allow the battery to continuously discharge power so you can recharge it many times over without decreasing its lifespan
• 2X-3X MORE BATTERY LIFE: Interstate's deep-cycle marine AGM batteries pack more power into each battery. The expected service life is 3x longer than conventional flooded batteries & 2x longer than an alloyed lead AGM battery. High-quality & unparalleled service make Interstate the preferred brand of marine dual-purpose batteries
• INTERSTATE TOUGH MARINE: Not all marine batteries are the same – but this one exceeds the rest. Built with thick plates to allow the battery to continuously discharge power so you can recharge it many times over, without decreasing its lifespan. This battery is not to replace batteries for automotive or mobility devices
• MOST TRUSTWORTHY POWER SOURCE: For 70 years, Interstate Batteries purpose has been to deliver the most Outrageously Dependable source of power to the world. Our customers come first, so we strive to create a positive experience for all. We recycle more batteries than we sell; please return to an Interstate All Battery Center near you so we can continue recycling

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NOCO BT31S Group 31 Heavy-Duty Battery Tray – Secure Mounting Solution

While not a battery itself, the NOCO BT31S is a must-have accessory for any group 31 battery installation. It’s a rugged tray designed to fit marine, RV, camper, and trailer batteries, and it comes with a heavy-duty 42-inch hold-down strap made from nylon webbing that can withstand over 120 kilograms of tensile force. This keeps your battery securely in place, even during rough terrain or choppy waters.

You’ll appreciate the impact-resistant construction that works down to minus 20 degrees Fahrenheit and is immune to acid, gas, oil, and UV degradation. The tray is easy to install and limits battery movement, reducing the risk of terminal damage or short circuits. If you’re mounting a group 31 battery, this tray is a simple, affordable way to protect your investment and ensure safe operation.

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• A rugged battery tray for group 31 batteries, including marine, RV, camper, and trailer batteries.
• Features a heavy-duty 42-inch hold-down strap with nylon resistant webbing that withstands a tensile load of over 120 kilograms of force.
• Impact-resistant down to minus 20 degrees Fahrenheit, withstands acid, gas, oil and other contaminants, and immune to UV exposure.
• Keeps your battery securely mounted and limits battery movement during transportation and operation.
• Meets United States Coast Guard (USCG) Code of Federal Regulations 183.420, American Boat and Yacht Council (ABYC) E-10.7 specifications, and frustration-free packaging.

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LiTime 12V 165Ah LiFePO4 Lithium Battery Bluetooth – Group 31 Size

LiTime’s 165Ah lithium battery is a game-changer for group 31 users who need maximum energy density and smart features. With 2112Wh of energy, it stores more than double the usable capacity of a typical 100Ah AGM battery, yet it fits in the same group 31 footprint. The built-in Bluetooth 5.0 lets you monitor real-time voltage, current, and state of charge from your phone, so you always know your battery status.

You’ll benefit from the 165A BMS that protects against overcharge, over-discharge, and short circuits, plus low-temperature cutoff to prevent charging below 32°F and discharging below -4°F. The IP65 waterproof rating and salt fog resistance make it ideal for marine environments. And with LiFePO4 chemistry, you get a stable 10-year lifespan and over 4000 cycles – far outlasting any AGM battery.

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• Bluetooth 5.0: Auto-connects, monitors real-time, controls discharge. Tracks battery status easy. Keeps your adventures powered smooth—no interruptions.
• Low-Temp Protection: Cuts off if charge <32°F/discharge < -4°F. Stops cold damage. Battery stays safe, reliable even in extreme cold.
• Multiple Protection : 20+ BMS safeguards, IP65 waterproof, salt fog-resistant. More durable in harsh spots. Battery lasts longer—less worry in tough conditions.
• Top Grade LiFePO4 Cells: Auto-grade cells, BMS blocks overcharge/overcurrent. Stable for 10 years. Reliable performance long-term—no frequent issues.
• Expandable to 33.79kWh: 4P4S (51.2V 660Ah) for more power. Fits RVs/home backup/trolling motors. Meets growing electricity needs easy.

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Marxon Group 31M Marine Battery Dual Purpose AGM – 12V 105Ah 825CCA

Marxon’s Group 31M battery is a dual-purpose AGM that delivers 105Ah capacity and 825CCA, making it a solid choice for starting and supplying power on boats and RVs. It’s designed to handle the vibrations and moisture of a marine environment, and its maintenance-free construction means you never have to add water or acid. The battery has a 200-minute reserve capacity, giving you plenty of run time for electronics.

You’ll appreciate the straightforward installation – the battery comes with screws and the terminal layout has left positive, right negative, consistent with standard group 31M orientation. Marxon has a US-based office and warehouse, so you get local support and a 24-month warranty. If you’re looking for a reliable, no-fuss AGM battery that’s backed by a responsive company, this is a strong contender.

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• Battery Parameters—Group 31M Battery dimensions: 12.99*6.61*8.35inch(L*W*H). 12V 105Ah 825CCA 200RC Terminal:Left:Positive, Right:Negative. Listing is for the Battery and Screws only.
• dual purpose— This means that the battery can be used as a starting battery to start RV and marine, and can also provide power for on Marine or RV electronics ( navigation aids, fish finders, running lights, radios, and trolling motors etc.)
• Safe to use— Maroxn group 31M battery are typically a bit larger than a standard car battery and are built to withstand the vibrations and conditions of a marine environment. Maintenance-free design make battery to use without adding acid and water to ensure your safe use
• US local office— We have established offices and warehouses in US. If product have any problems, we can solve it for you in USA. We provide 24 months warranty , and we will reply to your email within 12 hours
• Marine electrical systems are commonly set up in 12, 24, or 36 volts depending on the size of the watercraft and its trolling motor.If you have a 12-Volt trolling motor, you can choose from the 12V options that will suit your capacity requirements. If you have a 24-Volt trolling motor, you can use two, 12-Volt batteries in series with a multi-bank charger or multiple 24-Volt batteries in parallel to meet your capacity requirements. If you have a 36-Volt trolling motor, you can use one 36v trolling motor battery , or you can use three, 12-Volt batteries in series with a multi-bank charger.

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Mighty Max Battery MM-G31M 12V 110Ah Deep-Cycle Marine AGM – 825CCA 1000MCA

Mighty Max’s MM-G31M is a purpose-built marine dual-purpose battery with 110Ah capacity, 825 cold cranking amps, and 1000 marine cranking amps (MCA). This higher MCA rating means it’s especially good at starting boat engines, even in cold or humid conditions. The deep-cycle side provides 240 reserve capacity minutes, so you can run your trolling motor, fish finder, and lights for hours without killing the battery.

You’ll get a sealed, spill-proof AGM design that’s completely maintenance-free and resistant to vibration. The battery is built to handle the rigors of marine use, and the high MCA gives you extra confidence when you turn the key. It’s a great match for boats with larger engines or for those who want a battery that can handle both starting and sustained power demands.

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• Marine-Grade Confidence: Harness the endurance and dependable energy you need to power every journey on the water, on the road, off the grid, or wherever adventure takes you.
• Dual-Purpose Power: 110 Ah deep-cycle capacity delivers strong cranking power to start your engine and the long-lasting endurance to keep electronics and gear running for hours.
• Strong Starting Advantage: Delivers 825 CCA and 1000 CA for quick, dependable engine starts even in any climate or terrain.
• High Marine Cranking Power: Delivers 1000 Marine Cranking Amps (MCA) to start your engine with strength and reliability, giving boaters superior starting performance compared to standard marine batteries.
• Long-Lasting AGM Durability: Offers up to 700 cycles at 50% depth of discharge, delivering longer life compared to typical AGM marine batteries.
• Built strong for Real-World Conditions: Maintenance-free and spill-proof design delivers steady energy for waves, trails, and off-grid life, built with heavy-duty AGM technology for any rough terrain.
• Tough ABS Protection: Encased in a rugged ABS shell that resists impacts and heat, providing added safety and dependable energy in demanding environments.
• All-Season Versatility: Built to absorb vibration and harsh marine conditions, it delivers dependable power year-round and is ideal for boaters who need strong cranking power and steady energy for electronic accessories.
• Dimensions: Measuring 13.00 x 6.81 x 8.35 in, 9.37in Total Height and weighing 70.70 lbs
• Two-Year Warranty: Built to last and backed by a two-year limited warranty for added protection with every charge.

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VATRER POWER 12.8V 100Ah LiFePO4 Battery with Self-Heating & APP Monitoring

VATRER POWER’s self-heating LiFePO4 battery solves the cold-weather charging problem that plagues many lithium batteries. When the temperature drops below 32°F, the BMS activates heating pads to warm the battery to 41°F before allowing charging, so you can use it in winter without damage. The 100Ah capacity and 100A BMS provide reliable power for RVs, camping, and off-grid solar setups.

You’ll love the APP monitoring that tracks voltage, current, temperature, and cycle count in real time, giving you full control over your power system. The battery uses Grade A automotive LiFePO4 cells and has UL testing reports for safety. It’s also clean and green, with no heavy metals. With over 5000 cycles, this battery will last more than a decade, making it a smart long-term investment.

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• 【Grade-A Cells & Upgraded 100A BMS】VATRER POWER 100Ah self-heating LiFePO4 batteries with Automotive Grade A LiFePO4 cells have uncompromising quality and higher energy density with better stability, which makes it possible to ensure long-term recycling. And highest-level safety is based on UL Testing Reports for the cells inside the battery and upgraded BMS with heating pads to protect it from overcharging, over-discharging, over-current, and short circuits with excellent self-discharge rate.
• 【APP MONITORING】 Our batteries have listened to the suggestions of many users, so we have made a special battery with a communication function so that you can easily monitor the status of your battery in real time. This includes current, voltage, temperature, cycle, etc. Just download our APP on the phone according to the instructions. It brings great convenience to the user experience.
• 【Automatic Self-Heating】The 12V 100Ah LiFePO4 battery is equipped with an automatic self-heating function that will be activated by the BMS when the battery is connected to a charger at temperatures below 32°F. Heating will stop when the battery temperature reaches 41°F, and then the battery will start charging normally. This feature makes it possible to charge the battery at low temperatures without any issues. The battery’s operating environment is no longer restricted, making it more flexible and convenient to use.
• 【Safety & Unlimited Solar Energy】 The stable Lithium Iron Phosphate chemical structure makes LiFePO4 battery not burn or explode even at high temperature, short circuit, impact and drop. And it does not contain any heavy metals and rare metals and is more energy efficient, clean, green charging , which called green battery.
• 【Multi-Application】 With no acid in the lithium ion battery, you're able to safely mount in any position. This makes li-ion batteries perfect for marine, RV, campers, travel trailer, and off-grid applications! NOTE: The battery is suitable for energy storage rather than start-up. Please consult us in advance if needed.
• 【Kindly Attention】This battery with self-heating can not be connected with the regular version 12V 100Ah battery model in series or in parallel. The battery will activate the heating function only when the charging current is more than 10A.

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Buyer’s Guide: What to Consider

Choosing the right group 31 battery involves more than just picking the first one you see. You need to consider how you’ll use the battery, where you’ll mount it, and what kind of charging system you have. Below are the key factors to keep in mind when shopping for a group 31 battery for your boat, RV, or off-grid setup.

• Battery Type: AGM vs. Lithium vs. Flooded: AGM batteries are maintenance-free, vibration-resistant, and good for dual-purpose use. Lithium (LiFePO4) offers lighter weight, longer cycle life, and deeper discharge, but costs more upfront. Flooded batteries are cheaper but require regular maintenance and can leak.
• Capacity (Ah) and Reserve Capacity (RC): Amp-hours (Ah) define how much energy the battery stores. Reserve capacity (RC) tells you how many minutes the battery can deliver 25 amps before dropping to 10.5V. For deep cycling, look for at least 100Ah or 200+ RC.
• Cold Cranking Amps (CCA) and Marine Cranking Amps (MCA): CCA measures starting power in cold temperatures. For marine use, MCA is a better indicator because it’s measured at 32°F. Higher numbers mean easier engine starts. Group 31 batteries typically range from 800 to 1150 CCA.
• Dual-Purpose vs. Dedicated Starting or Deep Cycle: Dual-purpose batteries can start your engine and also provide steady power for electronics. If you only need starting power, a dedicated starting battery may save money. For heavy electronics use, a deep-cycle-only battery (like lithium) is often better.
• Vibration and Environmental Resistance: Marine and RV batteries face constant vibration. Look for AGM or lithium batteries with high vibration resistance ratings. Also consider IP ratings for water and dust ingress, especially if mounting in exposed locations.
• Size and Terminal Orientation: Group 31 batteries have standard dimensions, but terminal positions vary (left positive vs. right positive). Check your battery tray and cable lengths. Some batteries like the 31M have left positive, right negative. Always measure before buying.
• Charging Requirements and Compatibility: AGM and lithium batteries require specific charging profiles. AGM typically needs 14.4-14.7V absorption, while lithium needs 14.2-14.6V. Many modern chargers have AGM and lithium modes. Self-heating lithium batteries are essential for winter use.

Conclusion

Whether you prioritize raw starting power, deep-cycle endurance, or smart features like Bluetooth monitoring, the group 31 battery market has something for every need and budget. For most boaters and RVers, AGM dual-purpose batteries like the Interstate 31M-AGM-A or the Mighty Max MM-G31M offer a great balance of performance and value. If you want maximum capacity and longevity, the LiTime 165Ah lithium battery is a standout choice, especially with its Bluetooth monitoring. And for those who face cold winters, the VATRER POWER self-heating lithium battery is a game-changer.

Don’t forget to pair your battery with a secure mounting tray like the NOCO BT31S to keep it safe during travel. Ultimately, the best group 31 battery for you is the one that matches your power demands, climate, and budget. Take the time to match your needs with the battery’s specs, and you’ll enjoy reliable power for years to come.