A group battery size refers to the actual dimensions of the battery.
A Group 31 battery is suitable for boats and heavy-duty appliances onboard, vehicles, and other off-the-grid settings, as they’re designed to deliver excellent and reliable performance.
If you’re in the market for the best group 31 batteries, you’ve come to the right place. Keep on reading to learn more about the best batteries on the market.
What is a Group 31 Battery?
This is an industry-standard commercial battery that can be used for heavy trucks, boats, and other heavy applications. Thanks to its high-power output, this battery satisfies the demands of heavy equipment.
How to Select the Best Group 31 Batteries
Group 31 batteries can either be used to start the engine or run electric loads like light, any other appliance, or device on the boat. They’re also used to run vehicles and in other off-the-grid settings, where a powerful battery is needed.
A typical 31 group battery would measure about 13 x 6.8 x 9.44 inches and should deliver exceptional performance in all settings. Here are a few considerations to think about before buying the best group 31 batteries.
Weight
All 31 group batteries are a bit heavy, but some of them are lighter than others. A heavyweight battery will probably be sturdier and more efficient. However, if the weight is an issue in your application, you might need to look for a lightweight option.
Performance
The price is probably something that you should consider before shopping for a group 31 battery. However, you need to think first of how efficient this battery will be.
Make sure that you’re selecting a reliable battery that won’t malfunction when you’re using it. Since a group 31 battery will be used in critical applications, you should make sure that it will deliver exceptional performance in all weather conditions.
Look for a model that can always restart fast, even in bad weather, so your engine or motor will always be ready for use. You should also pick a model with a slow discharge rate, so the battery won’t lose power when it’s left unused for a long period. The reserve capacity is another factor to think about.
Recharge
A battery that can be recharged fast is a better option. This will allow you to use the battery whenever it’s needed with no delay or disappointments.
How to Make your Group 31 Battery Last Longer
Keeping your battery in good condition guarantees that it will deliver the same reliable performance for as long as you need it. Here are a few tips that can help you make your battery last longer.
- Start with proper mounting. Some batteries can be mounted in a single way, while others are more versatile. The battery box should be intact, and the cover should be properly placed. This will protect the contents of the battery in case of mechanical vibrations, and will also eliminate the risk of spilling the acid.
- Always try to recharge your batteries completely. Multiple engine starts, and driving your car or truck for short distances can affect the battery’s charging cycle. Make sure that every part of your recharging system is properly installed to keep your battery in excellent shape.
- Dirt, grease and other types of grim can cover the battery and its terminals, affecting its performance in the long run. Dirt can cause the battery to overheat, affecting the power output.
- Remove all signs of corrosion as soon as you spot them. Use a toothbrush to remove any rust off the battery’s terminals to guarantee the best performance. You can also coat the terminals with a corrosion inhibitor to prevent rust from accumulating.
- When not needed, turn the devices off. You might have turned off the truck or boat, but leaving the phone charger or radio on might sabotage the battery. Unplug any device that you’re not using to extend the battery’s life.
- Protect the battery from extreme weather conditions when possible. Some batteries are designed for extreme hot or cold weather, while others can’t handle extreme temperatures. Take a look at the optimum operating temperature before buying a group 31 battery.
Comparison Table of Group 31 Batteries
| Model | Battery TypeBattery Chemistry | Capacity (Ah)RC (min) | CCA MCA | Weight (lbs/kg) |
| AIMS Power LFP12V100A | Deep CycleLiFePO4 | 100~240 | — | 30.2 lbs; 13.7 kg- |
| Ampere Time 12V 100Ah | Deep CycleLiFePO4 | 100~240 | 280A 5s | 24.25 lbs; ~11 kg |
| Battle Born 100Ah 12V LiFePO4 | Deep CycleLiFePO4 | 100~240 | — | 29 lbs; 13.2 kg |
| Exide XMC-31 | Deep CycleAGM | 100200 | 9251110 | 68 lbs; 31 kg |
| ExpertPower EP12100 | Deep CycleLiFePO4 | 100~240 | — | 29.7 lbs; 13.5 kg |
| ExpertPower EXP100 | Deep CycleAGM | 100- | — | 63.94 lbs; 30 kg- |
| FLYPOWER 12V 100Ah | Deep CycleLiFePO4 | 100~240 | 100 cont.200A surge 3-5s | 24.3 lbs; ~11 kg |
| GreenLiFE Battery GL100 | Dual PurposeLiFePO4 | 100240 | — | 28 lbs; 12.7 kg- |
| Interstate DCM0100 | Deep CycleAGM | 1103h @23.2A | 351.5A 5 min | 67.5 lbs; ~30.6 kg |
| Lifeline GPL-31T | Deep CycleAGM | 105195 | 600750 | 69 lbs; 31.5 kg- |
| Lifeline GPL-31XT | Deep CycleAGM | 125230 | 650800 | 69 lbs; 31.5 kg- |
| Lifeline GPL-3100T | Dual PurposeAGM | 100228 | 810950 | 67 lbs; 30.4 kg- |
| Miady LFP100AH | Deep CycleLiFePO4 | 100~240 | — | 28.9 lbs; 13.1 kg- |
| Mighty Max ML100-12 DS-IGEL | Deep CycleGel | 100180+ | — | 68.2 lbs; 30.9 kg – |
| NorthStar ELT-AGM31 | Dual PurposeAGM | 100190 | 9251050 | 65.7 lbs; 29.8 kg- |
| NorthStar NSB-AGM31 | Dual PurposeAGM | 103220 | 11501370 | 75 lbs; 34.0 kg- |
| NorthStar NSB-AGM31M | Dual PurposeAGM | 103220 | 11501370 | 75 lbs; 34.0 kg – |
| Odyssey 31-PC2150S | Dual PurposeAGM | 100205 | 11501370 | 77.8 lbs; 35.3 kg |
| Optima 8052-161 D31M | Dual PurposeAGM | 75155 | 9001125 | 59.8 lbs; 27.1 kg |
| Renogy RNG-BATT-AGM12-100 | Deep CycleAGM | 104180+ | — | 66 lbs; 29.9 kg |
| Renogy RNG-BATT-GEL12-100 | Deep CycleGel-Cell | 100180+ | — | 60 lbs; 27.2 kg |
| Renogy RBT100GEL12-G1 | Deep CycleGel-Cell | 100~175 | — | 63.9 lbs; 29 kg |
| Renogy RBT100LFP12S-G1 | Deep CycleLiFePO4 | 100~240 | — | 26 lbs; 11.8 kg |
| Trojan T31-AGM | Deep CycleAGM | 102200 | — | 69 lbs; 31.3 kg- |
| Trojan T31-GEL | Deep CycleGell-Cell | 102200 | — | 70 lbs; 31.7 kg- |
| UPG UB121100 | Deep CycleAGM | 110- | — | 70 lbs; 29.8 kg- |
| VMAXTANKS SLR125 | Deep CycleAGM | 125260 | — | 75 lbs; 34 kg |
| VMAXTANKS MR137-120 | Deep CycleAGM | 120230 | -900 | 75 lbs; 34 kg |
| VMAXTANKS VPG12C-100LFP | Deep CycleLiFePO4 | 100~240 | — | 26.4 lbs; ~12.0 kg- |
| VMAXTANKS XTR31-135 | Deep CycleAGM | 135265 | 730920 | 77 lbs; 34.9 kg- |
| XS Power XP3000 | Deep CycleAGM | 120240 | — | 73 lbs; 33.1 kg- |
| Weize 12V 100Ah AGM | Deep CycleAGM | 100- | — | 60 pounds; 27.2 kg |
| Weize 12V 100Ah Gel | Deep CycleGel-Cell | 100<180 | — | 67 pounds; 30.4 kg |
| WindyNation BAT-NSAP12-100 | Deep CycleAGM | 106180+ | — | 67 lbs; 30.4 kg |
| Zooms 12V 100Ah | Deep CycleLiFePO4 | 100~240 | 100A cont. | 25.35 lbs; ~11.5 kg |
Reviews of the Best Group 31 Battery Options
These batteries are designed to work in the most challenging conditions, so they won’t disappoint you when you expect the best performance. Check out our top picks.
1. Odyssey 31-PC2150S Heavy Duty Commercial Battery
With an expected life between 3 and 10 years, this heavy-duty battery is designed to deliver the best performance in the most demanding conditions. It has a 70% longer cycle life than most other deep cycle batteries. It can deliver up to 400 cycles at 80% depth of discharge.
This battery is designed to deliver high stable voltage for longer periods, protecting your appliances and tools. It recharges faster than other batteries, as the recharge efficiency is enhanced compared to other lead batteries. It can be fully recharged to 100% within 4 to 6 hours, so you can use it safely for various applications.
It weighs 77.8 pounds and has a reserve capacity of 205 minutes. You can easily install and mount this battery anyway you like, thanks to its flexible design.
The design protects the battery’s components from mechanical vibrations, high impact shocks, and extreme temperatures. It can operate in all weather conditions as it’s designed to work between -40-degree Fahrenheit and 113-degree Fahrenheit. The battery is protected by a 3-year limited warranty and a 4-year full replacement warranty.
Buying this battery will be a good experience as long as you don’t have to deal with customer support. The company might take weeks to test and eventually replace a faulty product, so it’s not the most convenient option. Moreover, it’s more expensive than other choices on the market.
What We Like
- Well-built battery with long service life.
- Longer cycle life.
- Expected service life is between 3 and 10 years.
- Easy to install and multiple mounting options.
What We Don’t Like
- The customer support isn’t impressive.
- More expensive than other 31 group batteries.
2. NorthStar NSB-AGM31M AGM Group 31 Marine Battery
Thanks to the latest lead AGM technology, this battery is designed to deliver maximum performance. The battery will deliver more than 900 cycles with 50% depth discharge. It quickly starts to power any device with a faster recharge than conventional batteries.
You don’t have to worry about maintaining and cleaning the terminals of this battery. The OEM fit is built to comply with the latest industry standards. The plastic housing is sturdy enough to withstand heavy-duty operation and doesn’t get affected by heat and mechanical vibrations.
You can easily install it in multiple positions, even on its side. It weighs 74.5 pounds, but it’s more expensive than other products.
What We Like
- Lead AGM technology for maximum performance.
- Can deliver more than 900 cycles.
- No maintenance or cleaning.
- Durable plastic housing.
- Can be installed in multiple positions.
What We Don’t Like
- More expensive than other batteries.
3. Deka East Penn 8A31DTM Group 31 AGM HD Battery
This battery is one of the lightest on the market, weighing 69 pounds and delivering exceptional performance in the most challenging settings. This battery is strong enough to start and keep your engine going without any delays or loss of power.
The AGM completely sealed plastic housing is durable and reliable, eliminating the risk of acid leaks and decreasing the need for cleanup. It provides more power with a capacity reserve of 210 minutes.
With a low discharge of 2% per month, the battery is an excellent choice for those who need a reliable battery to power several tools. It also charges fast compared to other batteries but has a limited warranty of 1 year.
What We Like
- Reliable battery with excellent performance.
- Sealed plastic housing to prevent acid leaks.
- Low discharge rate.
- Fast charging.
What We Don’t Like
- Short warranty.
4. Optima Batteries 8052-161 D31M Deep Cycle Battery
This is one of the lightest batteries, weighing only 59.8 pounds. The stainless-steel stud posts add durability, making it an excellent choice for heavy-duty use.
With a reserve capacity of 155 minutes, this deep cycle battery will deliver constant and adequate performance in the most challenging settings. The battery can start even in bad weather to help you run your tools and motors efficiently. It’s fifteen times more resistant to vibrations for maximum durability.
Thanks to the slow discharge rate, it will still provide power even when it’s left unused for a long period. This battery is the right choice for power tools and heavy equipment.
The spiral design offers more control and prevents acid spills. It recharges faster compared to other batteries, so you can depend on it. However, for what it offers, this battery is a bit pricey.
What We Like
- Spiral design to minimize the risk of acid spills.
- Consistent and reliable performance.
- Fast recharging and slow discharge rate.
- Resistant to vibrations.
What We Don’t Like
- A bit pricey for what it offers.
5. VMAX MR137-120 AGM Battery
This battery is designed to deliver a service life between 8 and 10 years. It features an electrolyte suspension system that fully absorbs and contains the electrolyte without silica gel or any other harmful contaminants. Not only will this be safer, but it also guarantees that there will be no leakage or corrosion that will affect the battery’s performance.
Thanks to the heavy-duty lead-tin alloy, this battery is designed to deliver unmatched performance in the most challenging applications after repeated discharges. As a result, this battery will prove good value for money as you can expect the same performance over a long period. It has a reserve capacity of 230 minutes.
You don’t have to worry about maintaining or examining this battery. There’s no drop in output whether you use it for a vehicle, boat, or any other application, and you don’t have to add water or check the level of electrolytes. The AGM design preserves the battery and guarantees the consistency of the performance.
It’s a little lighter than other options on the market, weighing 75 pounds and measuring 13 X 6.8 X 8.8 inches. However, with a 1-year warranty, buyers can be a little skeptical about buying this battery.
What We Like
- Long service life.
- Electrolyte suspension system to prevent leakages.
- Performance doesn’t drop over time.
- Maintenance-free design.
- Low self-discharge.
What We Don’t Like
- Short warranty.
Wrap Up
Having a battery that won’t disappoint you is a big plus because you know you can depend on it in the most challenging conditions. We chose the VMAX MR137-120 AGM Battery as our top choice because it has a long service life and will deliver reliable performance in hot and cold weather. Moreover, the design eliminates the risk of leaks, so you can enjoy exceptional power output for long periods.