WEST MARINE

Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes

Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 0
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 1
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 2
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 0
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 1
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes image number 2
product video
WEST MARINE
Group 31 Dual Purpose Marine AGM Battery, 105 Amp Hours, 800 Cold Cranking Amps, 1,000 Marine Cranking Amps, 200 Reserve Minutes
See Product Details Advice & How-To
5 out of 5 Customer Rating
54 ReviewsWrite a Review
95%
of respondents would recommend this to a friend
Model # 15020258 Mfg # WM8A31DTM
Pay with on orders over $50
See Product Details Advice & How-To
5 out of 5 Customer Rating
5 out of 5 Customer Rating
54 ReviewsWrite a Review
95%
of respondents would recommend this to a friend
Model # 15020258 Mfg # WM8A31DTM
Orders placed by 3 PM EST typically ship the same day. Orders placed after this time will be processed the next business day.
Quantity not available. Please adjust.
Temporarily Out of Stock
Email Icon
Thank you! We'll let you know when it's back in stock.
-
+

Complete Your Purchase

Replace your flooded batteries with Absorbed Glass Mat (AGM) batteries. They’re more rugged, accept higher charging current, are sealed, safer and submersible.

AGM Batteries are great in both deep cycle and starting applications. They charge more quickly than conventional batteries and have low 3% monthly self-discharge rates. The spill-proof, valve-regulated design eliminates acid spills and terminal corrosion. AGM batteries are safer to operate than conventional flooded batteries, as the chance of explosion or acid spray is reduced which allow them to be installed in almost any location and any position (except upside-down).

Manufactured in the U.S. for West Marine by East Penn, one of the most reputable battery companies in the country. Each battery receives over 250 quality control checks to guarantee consistent and superior performance. East Penn’s award winning factory leads the industry in closed loop and sustainable practices. Nearly all of the plastics, lead and acid are recycled, so our batteries are great for your boat and the environment.

Key Features

  • Dual Purpose batteries deliver high starting and moderate deep cycle power; Ideal for boaters who want high cranking power plus dependable power for power-hungry electronic accessories
  • Shock-absorbing glass mat separators resist vibration and damage that can shorten the life of a battery; 20 times more vibration resistant than flooded batteries for wave-pounding protection
  • Enhanced durability design to withstand wear of extended cycling service
  • Superior electrolyte retention prevents dry out and acid leaks
  • Safer to install and transport with no-spill design to prevent leaking acid
  • High freeze-resistance provides better all-weather performance
  • Lower current resistance separators improve current flow for faster starts
  • Manufactured in the USA
  • Rated at 300 cycles

Specifications

  • Group Size: Group 31
  • Terminal Type: Flush combination terminal w/ 3/8” and SAE Post, hex nuts included
  • Amp Hours (Ah): 105
  • Cold Cranking Amps (CCA): 800
  • Marine Cranking Amps (MCA): 1000
  • Reserve Minutes: 200
  • Weight: 69 lbs.
  • Dimensions: 12 15/16"L x 6 3/4"W x 9 3/8"H
  • Warranty: 18-month free replacement

Core charge will apply to battery purchase if an old 12V battery is not exchanged at the time of purchase.

Amperage Hours 105
Battery Type Sealed, AGM, Dual Purpose
Best Use Dual Purpose
Cold Cranking Amps 800 CCA
Dimensions 6 3/4" Width x 9 3/8" Height x 12 15/16" Length
Marine Cranking Amps 1000 MCA
Reserve Minutes 200
Type Tapered Stud
Voltage 12 Volts DC
Warranty 18 Months Free Replacement
Warning
Battery posts, terminals and related accessories contain lead and lead compounds, chemicals known to the State of California to cause cancer and reproductive harm. Batteries also contain other chemicals known to the State of California to cause cancer. Wash hands after handling. For more information, go to www.P65Warnings.ca.gov

Amperage Hours 105
Battery Type Sealed, AGM, Dual Purpose
Best Use Dual Purpose
Cold Cranking Amps 800 CCA
Dimensions 6 3/4" Width x 9 3/8" Height x 12 15/16" Length
Marine Cranking Amps 1000 MCA
Reserve Minutes 200
Type Tapered Stud
Voltage 12 Volts DC
Warranty 18 Months Free Replacement
Warning
Battery posts, terminals and related accessories contain lead and lead compounds, chemicals known to the State of California to cause cancer and reproductive harm. Batteries also contain other chemicals known to the State of California to cause cancer. Wash hands after handling. For more information, go to www.P65Warnings.ca.gov

Review Snapshot

by PowerReviews

54 ReviewsWrite a Review
95%
of respondents would recommend this to a friend

Ratings Distribution

Pros

Cons

No Cons

Best Uses

Describe Yourself

Most Liked Positive Review

A great battery

I am replacing now my two house batteries on my sailboat after 6 3/4 years of use. Simply incredible.

Versus

Most Liked Negative Review

Bad Batteries

I usually do not write reviews unless a product is really bad. Not only are these way overpriced, but they also do not last. I am already on my soon to be 3rd replacement, each only lasting at max 3 years, and I live in the south, where it is warm (not cold). I also charge the batteries regularly wi...

Reviewed by 54 customers

Awesome so far

Submitted 13 days ago

By Ming

From Undisclosed

Verified Buyer

Submitted as part of a sweepstakes entry

So far so good! First time I've purchased this type of boat battery - engines fire up much better since buying thesw!

Was this review helpful to you?

Great battery, wish it had a better warranty.

Submitted 13 days ago

By Sailer Bob

From Undisclosed

Verified Buyer

Submitted as part of a sweepstakes entry

These batteries are long lasting if you take care of them. They should better warranties though. Other Deka batteries offer twice the replacement warranty.

Was this review helpful to you?

I've purchased 2 Batteries

Submitted 26 days ago

By SeaRay 270

From Undisclosed

Verified Buyer

Submitted as part of a sweepstakes entry

Glad to see that these batteries were still available. Thats a reliable battery.

Was this review helpful to you?

bought more than i can count

Submitted 1 month ago

By jaymz

From Undisclosed

Verified Buyer

Submitted as part of a sweepstakes entry

these always last

Was this review helpful to you?

Good Value

Submitted 1 month ago

By Nick

From Undisclosed

Verified Buyer

Submitted as part of a sweepstakes entry

I bought 3 Group 31 AGM batteries while they were on sale. I paid for them online and the staff was nice enough to hold them for me until I could pick them . I am switching to AGM from gel cell due to availability and cost. Will be installing them shortly. Have had good luck with West Marine gel cells in the past and expect to have good luck with these too.

Was this review helpful to you?

Q&A

Showing 10 out of 34 Questions

Q
Can this battery be used for multiple marine applications?: Is this battery versatile enough to be used across various marine setups, such as boats and yachts?
Asked by Undisclosed
Open Reply - West Marine SupportYes, this battery is versatile and can be used across different marine setups, including boats, yachts, and RVs, making it a reliable choice for various applications.Was this answer helpful to you
Q
Is this battery maintenance-free?: Do I need to perform any regular maintenance, or is this battery designed to be maintenance-free?
Asked by Undisclosed
Open Reply - West Marine SupportThe battery is maintenance-free, so there's no need to check water levels or perform other regular upkeep. It's built to offer dependable performance without additional care.Was this answer helpful to you
Q
How many amp hours does this battery provide?: What is the amp hour capacity of this battery, and is it enough for powering multiple devices?
Asked by Undisclosed
Open Reply - West Marine SupportThis battery delivers 105 amp hours, which is sufficient for running multiple devices and systems, providing ample power for extended use on boats.Was this answer helpful to you
Q
What benefits does AGM technology offer for this battery?: How does AGM technology enhance the performance and durability of this battery?
Asked by Undisclosed
Open Reply - West Marine SupportAGM (Absorbent Glass Mat) technology offers spill-proof, maintenance-free operation, and enhances resistance to vibrations. It ensures consistent performance and longevity, even in tough marine conditions.Was this answer helpful to you
Q
Is this battery suitable for both starting engines and deep cycling?: Can this battery reliably start engines and also support electronics for extended periods?
Asked by Undisclosed
Open Reply - West Marine SupportYes, this dual-purpose AGM battery is designed to provide reliable cranking power for starting engines, as well as deep cycling to support electronics over long durations.Was this answer helpful to you
Q
I just purchased a boat with 4 of these batteries for the house DC system and another for the starter. They were installed August of 2011. I need to replace them, I believe. Scenario; in the sea trial the windlass operated at probably 1/3 of normal speed. The surveyor noted one of the house bank had a hot cell and it is warmer than the other 3 house batteries. Couple of Q's: 1) The Link 10 monitor shows the bank at 13.25 - 13.30 volts, with the status bar showing fully charged and only 28.1 Ah. Being that they are "fully charged" according to the monitor shouldn't they have a 100Ah if healthy? Are they most likely toast even if only one of them is hot? 2) Assuming all else is functioning properly, which I hope to verify prior to installing new batteries, what is recommended replacement battery of the exact same size and Ah? And if I want to increase Ah are there same dimension batteries you recommend? Very broad strokes I understand but your help is appreciated. Thank you.
Asked by Tim
Verified Reply - BenFor same form size and Ah, the replacement is this Model # 15020258 | Mfg # WM8A31DTM. At the age of eight years old and showing signs of failure from what you've mentioned here, it is recommended to replaced the batteries. It is best to replace all batteries in the bank at the same time to ensure health of the system. For determining if more Ah are needed, you may be interested in our advisor Sizing Your House Battery Bank: https://www.westmarine.com/WestAdvisor/Sizing-Your-House-Battery-BankWas this answer helpful to you
Q
I purchased a ProSport20 dual bank onboard battery charger for this battery. I want to make sure I charge with correct charge settings. I'm assuming it's the first charging setting but just want to make sure. Didn't see any West Marine high performance blue cap AGM battery's on your website. The information I got was from the ProSport20 manual. Thanks The first is standard flooded (lead acid) and AGM- sealed. Which charges @ 14.6 VDC absorption, 13.4 VDC. "Black Cap" Second is AGM High Performance- sealed (OPTIMA, Odyssey, West Marine Brands). Charging profile is 14.7 VDC Absorption 13.6 VDC Float. "Blue cap" Please verify correct charge setting for this battery. Thank you
Asked by Frank
Verified Reply - JordanThe second option is the correct setting. That battery is a sealed AGM battery.Was this answer helpful to you
Q
I'm programming a Balmar external regulator governing a Balmar 100 amp alternator. Balamr recommended AGM voltage settings for AGM's at 14.38 v bulk, 14.18 v absorption and 13.4 v float. Do the recommended bulk, absorption & float voltages for the West Marine AGM Grp 31 battery match Balmars recommendation? I've been running 3 West Marine AGM banks (2 house & 1 eng start) for 3 years and they have performed very well. I also have a 100 watt solar panel that keep all topped off year-round in NW Washington state and SE Alaska.
Asked by Capt Bob
Verified Reply - StephenYes, the recommended settings will be fine with this battery.Was this answer helpful to you
Q
Does this only have the 2 tapered terminals or is there a lug with a nut to attach to as well?
Asked by Ian
Verified Reply - StephenThis battery has flush combination terminal w/ 3/8” and SAE Post, hex nuts included.Was this answer helpful to you
Q
Price of extended warranty
Asked by Lovel
Verified Reply - MaureenUnfortunately, West Marine does not offer an extended warranty on batteries. Was this answer helpful to you