Interstate Marine Batteries: Lineup Guide

June 13, 2026 · Marine Battery Source

Interstate is one of the most widely recognized battery names in the country, and its marine lineup covers nearly every role on a boat: cranking, deep-cycle, dual-purpose and lithium. This guide walks through the Interstate marine batteries in our store, what each line is for and how to pick the right one. Specs come from our product listings, based on manufacturer information. Check the product page for current details.

Interstate’s marine lines

Flooded starting batteries

Designed for engine cranking, with high CCA and MCA ratings. Examples include the 27M-XHD (800 CCA, 1000 MCA, 182 minutes reserve) and the 24M-XHD (800 CCA). Smaller models like the 24M-HD (500 CCA) suit smaller outboards. Listed warranties are typically 12 months free replacement.

Flooded deep-cycle (SRM and M-series)

The SRM line is Interstate’s flooded deep-cycle marine battery: SRM-24 (81Ah), SRM-27 (88Ah), SRM-31 (98Ah) and SRM-4D (195Ah). They also list cranking ratings, so they can handle light starting duty. Warranties are listed at 12 months free replacement for most sizes and 6 months for the 4D.

Enhanced flooded (EFB)

EFB batteries are an improved flooded design with better cycling durability than standard flooded batteries. Interstate lists a 24M-EFB (77Ah, 590 CCA) and 27M-EFB (90Ah, 675 CCA), each with 24 months free replacement.

AGM dual-purpose

Sealed, spill-proof batteries for starting and deep-cycle use. Interstate lists two tiers:

Standard AGM: 27M-AGM (85Ah, 850 CCA), 31M-AGM (100Ah, 925 CCA) and 34M-AGM (62Ah, 800 CCA), each with 36 months free replacement.
AGM-A: 24M-AGM-A (70Ah), 27M-AGM-A (90Ah) and 31M-AGM-A (100Ah), each with 24 months free replacement and lower prices.

Lithium

Interstate’s LiFePO4 marine batteries:

12V 60Ah, group 24M
12V 100Ah, group 27M
12V 100Ah dual-purpose, group 24M (1000 cranking amps)
24V 60Ah, group 31M
36V 50Ah, group 31M

Most list 60 months free replacement; the 24M dual-purpose lists 36 months.

Which Interstate battery for which job

Job	Good Interstate choices
Starting an outboard	27M-XHD, 24M-XHD, 31M-AGM
Single battery for start and accessories	27M-AGM, 31M-AGM, Li24MDP lithium
House bank	31M-AGM, SRM-31, Li27M 12V 100Ah
12V trolling motor	SRM-27, 27M-EFB, Li27M 12V 100Ah
24V trolling motor	Two 12V batteries, or Li31M 24V 60Ah
36V trolling motor	Three 12V batteries, or Li31M 36V 50Ah

Key takeaways: Interstate Marine Batteries: Lineup Guide

Group sizes

Interstate marine batteries carry “M” group sizes (24M, 27M, 31M, 34M, 4DM). They follow the standard group dimensions, typically with marine-friendly terminals. Measure your tray and check terminal type before ordering.

Flooded vs EFB vs AGM vs lithium

Flooded: lowest cost, needs watering and ventilation.
EFB: better cycling than standard flooded, still vented.
AGM: sealed, vibration resistant, no watering, higher cost.
Lithium: lightest, most usable capacity and cycles, highest upfront cost.

For saltwater boats, sealed batteries reduce corrosion and maintenance; see sealed vs vented batteries for saltwater.

Reading Interstate’s ratings

CCA (cold cranking amps): current at 0°F for 30 seconds while staying above a minimum voltage.
MCA (marine cranking amps): the same test at 32°F, so MCA is higher than CCA.
Reserve capacity: minutes at 25A before reaching 10.5V. Useful for comparing deep-cycle performance.

Match or exceed your engine maker’s cranking requirement.

Warranties

Interstate lists free-replacement periods by model, which are among the clearest in our store. Lithium models list up to 60 months, AGM up to 36 months, EFB 24 months and most flooded models 12 months. Read the terms on each product page.

Interstate vs other brands

Interstate’s strength is breadth, especially in lead-acid. Compared with Trojan, Interstate covers starting and dual-purpose duty, while Trojan focuses on deep-cycle; see the Trojan marine batteries guide. Compared with lithium specialists, Interstate’s lithium line is smaller but includes 24V and 36V single-case options. For lithium alternatives, see the ECO Battery guide, and for charging lithium trolling banks, see Allied Lithium chargers. If you’re weighing Interstate lithium against Interstate AGM, read Interstate lithium vs AGM, and if you’re comparing lithium specialists, see Dakota Lithium vs Battle Born.

Browse all brands in marine battery brands compared and marine battery comparisons, or read the lithium marine battery buyer’s guide.

Choosing between AGM tiers

Interstate’s two AGM tiers can be confusing. Both are sealed, spill-proof dual-purpose batteries in the same group sizes. The standard AGM models list higher cranking ratings and longer warranties (36 months free replacement), while AGM-A models list lower cranking ratings, 24-month warranties and lower prices. For example, the 31M-AGM lists 925 CCA and the 31M-AGM-A lists 825 CCA, both with 100Ah. If your engine’s cranking requirement is modest and you want to save, AGM-A makes sense. For big outboards, cold climates or longer coverage, the standard AGM is the safer choice.

Choosing between flooded, EFB and AGM for trolling

For a 12V trolling motor on a budget, the SRM-27 flooded deep-cycle is the entry point. The 27M-EFB costs a bit more and lists better cycling durability and a longer warranty, while still being a vented battery that needs ventilation. AGM costs more again but removes watering and spill concerns. For heavy daily use, lithium’s cycle life usually pays back the higher price over time, especially on 24V and 36V systems where you’d otherwise buy two or three batteries.

Installation notes

Secure every battery with a hold-down; flooded batteries must stay upright.
Vent compartments with flooded and EFB batteries.
Set chargers to the correct profile: flooded, AGM or lithium.
Protect terminals and check torque twice a season.
On lithium models, fuse the positive close to the battery and use a DC-DC charger for alternator charging if needed.

Example setups

Center console, single outboard. A 27M-XHD starting battery and a 31M-AGM house battery, with an automatic charging relay and a 2-bank charger.

Pontoon. One 27M-AGM dual-purpose, or two if you run a stereo and lights for long afternoons.

Bass boat. A 31M-AGM start and electronics battery and a Li31M 36V 50Ah trolling battery with a 36V lithium charger.

Shop all Interstate products.

Frequently asked questions

Are Interstate marine batteries good?

Interstate offers a broad marine lineup with clear free-replacement warranties. Choose the line that matches your job.

What’s the difference between Interstate AGM and AGM-A?

Both are sealed AGM dual-purpose. Standard AGM models list 36-month warranties and higher CCA; AGM-A models list 24-month warranties at lower prices.

Does Interstate make lithium marine batteries?

Yes: 12V 60Ah, 12V 100Ah, 12V 100Ah dual-purpose, 24V 60Ah and 36V 50Ah.

What’s the warranty on Interstate lithium?

Most models list 60 months free replacement; the 24M dual-purpose lists 36 months.

What does the M in 27M mean?

It denotes a marine version of the group size, typically with marine terminals.