Most marine and RV batteries fail you at the worst moment dead cells after a cold night at anchor, an AGM bank that quits at 50 percent capacity, 130 lbs of weight doing half the work it should. The Epoch 12V 300Ah Essential Series LiFePO4 battery (SKU: 12300A-H) was built to fix all three problems in a single Group 31 package that fits where your old battery already lives.
Owners switching from paired lead-acid or AGM banks report dropping 100 to 400 lbs of battery weight while gaining two to three times more usable capacity in the same compartment, on the same cable runs, without rebuilding the battery bay. Sailors have run overnight at anchor on electronics, refrigeration, and cabin lighting without touching the generator. Anglers have trolled for over four hours using less than 15 percent of a two-battery parallel bank. RV owners have run an inverter, a 12V refrigerator, and an air conditioner for three consecutive days and still had charge remaining.
One 12300A-H weighs 58 lbs and delivers 300Ah of fully usable capacity. Two paired Group 31 lead-acid batteries delivering the same usable capacity weigh over 200 lbs and require regular maintenance. The Group 31 form factor means it drops into the space your old battery already occupies on most vessels and vehicles.
Built-in self-heating for cold-water operation
Standard lithium batteries cannot be safely charged below freezing. The 12300A-H solves this with an internal heating element that activates automatically through the BMS the moment temperatures drop below the safe charging threshold. Charging is enabled down to -4 degrees Fahrenheit (-20 degrees Celsius) with heating active making this battery suitable for year-round operation in northern climates, cold-weather fishing seasons, and early-spring boating where overnight temperatures frequently fall below freezing. The heater draws its power from incoming charge current, not from the battery itself, so it does not drain the pack while connected to solar or shore power.
Bluetooth monitoring with security PIN
The battery connects to the free Epoch Li-Ion App on iOS and Android via Bluetooth. The app displays real-time state of charge, cell-level voltages, current amps in and out, temperature readings, and a battery event history log. A unique security PIN is printed on the top of each battery and is required on first connection this prevents anyone nearby from connecting to your battery, reading its data, or changing its configuration. The PIN is permanent and cannot be changed. Photograph it when you install the battery and keep it somewhere accessible.
When two or more batteries are connected in parallel, the app detects the bank configuration automatically and displays all units together. Owners running parallel banks report checking state of charge from inside the cabin or the cockpit without ever opening a hatch and without needing a separate external shunt.
EVE prismatic cell construction
The 12300A-H is built using EVE prismatic LiFePO4 cells. Epoch Batteries has a direct, long-established supply relationship with EVE and has been involved in selecting every component cells, BMS, and heating elements since the product was first designed. Most battery brands in this segment do not disclose which cells are inside their products or which grade of cells is used. Epoch publishes this information because it matters to informed buyers.
Scalable for larger systems
Connect up to four batteries in series for a 48V system or up to four in parallel for a 1,200Ah bank at 12V. Full 4S4P configuration is supported. Many owners start with a single 300Ah unit, confirm it works in their system, and add a second battery later the bank expands without replacing any existing hardware or rewiring the system from scratch.
11-year manufacturer warranty
Epoch Batteries provides an 11-year limited warranty from the original purchase date. The warranty applies to the original owner and is non-transferable. Registration is required within 90 days of purchase for full details see the Warranty tab or contact us. Epoch's warranty service is US-based. The warranty does not cover damage from gross negligence, accident, incorrect installation, or use outside manufacturer specifications.
Epoch Batteries is a veteran-owned company with US-based engineering and customer support, holding memberships with NMEA, ABYC, NMMA, and RVDA.
Is this battery right for your setup? This battery is a strong match if:
You are replacing two or more Group 31, Group 24, or Group 27 lead-acid or AGM batteries and want to consolidate into one unit
You need a heated lithium battery that charges safely in freezing conditions without manual intervention
Your battery compartment fits Group 31 dimensions (13.75 inch base length, 7.63 inch width, 10.50 inch height with terminals)
You run a 12V house bank on a sailboat, powerboat, trawler, RV, or camper van and want more usable capacity without a full system rebuild
You want Bluetooth state-of-charge monitoring without purchasing a separate shunt
You plan to expand capacity over time this battery supports parallel and series expansion up to 1,200Ah or 48V
Consider a different product if:
You store your vessel or vehicle in an unheated location over winter without any connection to shore power or solar the self-heating element in this battery cannot be disabled and will draw the battery down in sustained freezing conditions without a charge source
You need Victron CANBUS communication for direct BMS-to-GX integration this Essential Series model does not include that feature. The Epoch V2 or Elite Series models do
You need a single battery to run a 3,000W or larger inverter continuously the 200A BMS limits single-battery continuous output to approximately 2,560W. Two batteries in parallel remove this constraint
Features and Applications
Key features
LiFePO4 chemistry: Lithium iron phosphate is thermally stable and does not experience thermal runaway under normal operating conditions. Safer chemistry than other lithium-ion types.
Built-in self-heating element: Enables safe charging at temperatures as low as -4 degrees Fahrenheit (-20 degrees Celsius). Activates automatically through the BMS. Draws approximately 10 to 11 amps from incoming charge current.
Bluetooth monitoring with security PIN: Free Epoch Li-Ion App for iOS and Android. Displays SoC, cell voltages, current, temperature, and event history. PIN-protected against unauthorized access.
Smart BMS protection: Protects against over-voltage, under-voltage, overcurrent, short circuit (800A at 500 microseconds), over-temperature, and under-temperature.
EVE prismatic cells: Named premium cell supplier. Cell grade and quality processes selected by Epoch at the manufacturing stage.
4,000+ cycle life: Significantly longer service life compared to lead-acid and AGM batteries rated for 200 to 500 cycles.
Group 31 form factor: 13.75 inch base length, 7.63 inch width, 10.50 inch height with bolt terminals. Fits standard marine and RV Group 31 battery trays.
58 lbs: Substantially lighter than equivalent lead-acid capacity, reducing vessel or vehicle weight.
Scalable configuration: Max 4 in series (48V) or 4 in parallel (1,200Ah). Full 4S4P supported.
Certifications: RoHS compliant, CE marked, UN38.3 transport certified.
11-year manufacturer warranty: Original owner, non-transferable.
Veteran-owned company: US-based engineering, customer support, and warranty service.
Marine applications
The 12300A-H is suited for use as a marine house bank battery on sailboats, powerboats, trawlers, and fishing vessels. The Group 31 dimensions fit standard marine battery boxes and trays. Customers have installed this battery on vessels ranging from day boats to offshore cruising sailboats preparing for extended passages.
Sailboat house bank
Owners replacing paired lead-acid 8D or Group 31 banks report nearly tripling their usable amp hours while cutting battery weight by more than half. At-anchor overnight use covering navigation instruments, a 12V refrigerator, and cabin lighting no longer requires running the generator before sunrise.
Trolling motor power
Two batteries wired in series deliver 24V for electric trolling motors. Anglers report completing a full day of trolling, maneuvering, and repositioning over four hours of continuous use and returning to the dock with more than 85 percent of total bank capacity remaining.
Powerboat house loads
Unlike lead-acid banks that sag voltage as they discharge, LiFePO4 holds near-nominal voltage through most of its discharge curve. Navigation electronics, chart plotters, VHF radios, and onboard refrigeration run at consistent performance levels from full charge down to the low-voltage cutoff.
Offshore and coastal cruising
Owners preparing for extended passages including one customer outfitting for a full circumnavigation have chosen this battery for its combination of high capacity, low weight, self-heating for cold-latitude charging, and Bluetooth monitoring that works from below decks without opening the battery compartment.
RV and overland applications
Boondocking and dry camping
Two batteries wired in parallel provide 600Ah and 7.68 kWh. Owners report running an inverter, a 12V compressor refrigerator, and an air conditioner simultaneously for over 70 hours and checking the Bluetooth app to find nearly half the bank still available. Five-night off-grid trips with moderate solar recharging have ended with 30 percent capacity remaining.
Camper van builds
Van converters replacing four 100Ah batteries with two 300Ah units report gaining capacity while removing over 150 lbs from the build. The Group 31 footprint fits standard van battery trays in Sprinter, Transit, and Promaster configurations. The Bluetooth app shows real-time draw from each load refrigerator, lighting, water pump, USB chargers without wiring a separate shunt.
Travel trailers and 5th wheels
Owners replacing two stock Group 31 lead-acid batteries with a single 12300A-H report more than doubling their usable amp hours in the same battery compartment. A single battery has powered a 12V compressor refrigerator, interior lighting, a water pump, and a furnace blower for two to three days without a generator or solar recharge.
Motorhomes (Class A, B, C)
The Group 31 form factor fits under-step and slide-out compartments in Class B and C motorhomes where larger battery formats will not. Professional RV solar installers report specifying this battery routinely for customer upgrades. Owners who replaced six-volt golf cart battery banks report gaining more total capacity while removing close to 400 lbs from the coach.
Confirmed installations by verified buyers
Marine vessels:
Jeanneau 36.2 Hallberg-Rassy sailboat Offshore trawlers Bass boats Fishing vessels 24V trolling motor setups
Motorhomes and vans:
Winnebago View (2012, 2018, 2021) Winnebago Solis Winnebago Travato 22/23 Thor Sequence 20K Thor Tellaro 20L Renegade Vienna Roadtrek Zion Slumber Coachmen Leprechaun 260DS Newmar motorhome Sprinter van builds
Travel trailers, 5th wheels and Airstream:
Airstream 27 GT (2023) Airstream Globetrotter 27FTB 1965 Airstream Carvel Grand Design 303RLS InTech Sol Dusk (2024) Oliver Legacy Elite II Bigfoot trailer Cougar travel trailer Outdoors RV (2017)
Compatibility is based on customer-submitted reviews. Verify your specific compartment dimensions before purchase. Some installations required minor handle trimming or longer cable leads. Consult your vessel or vehicle documentation for battery bay specifications.
Tech Specs
Electrical specifications
Electrical
Nominal voltage
12.8V
Chemistry
Lithium Iron Phosphate (LiFePO4)
Cell configuration
4S1P
Cell manufacturer
EVE prismatic cells
Capacity
300Ah
Energy capacity
3.84 kWh
Operating voltage range
10V to 14.6V
Charging voltage range
14.0V to 14.6V
Max charge voltage
14.6V
Recommended charge profile
14.4V Bulk, 14.4V Absorption, 13.8V Float
Max continuous charge current
200A
Max continuous discharge current
200A
Max continuous discharge power
2,560W
Peak discharge current
400A (3 seconds)
Short circuit protection
800A at 500 microseconds
Cycle life
4,000+
Series / Parallel
Max 4 in series (48V) / Max 4 in parallel (1,200Ah) 4S4P supported
Temperature specifications
Temperature
Charge temperature range (with heating)
-20°C to 55°C (-4°F to 131°F)
Discharge temperature range
-20°C to 60°C (-4°F to 140°F)
Optimal discharge temperature
15°C to 35°C (59°F to 95°F)
Storage temperature
0°C to 35°C (32°F to 95°F) max 12 months
Recommended storage charge level
50% to 100% SoC cycle every 3 months
Physical specifications
Physical
Weight
58 lbs (26.3 kg)
Length (base)
13.75 inches
Length (with handles)
15.25 inches
Width
7.63 inches
Height (without bolt terminals)
10.00 inches
Height (with bolt terminals)
10.50 inches
Battery group
Group 31
Terminal type
M8 bolt terminals
BMS and safety
BMS Protection
Over-voltage protection
Included
Under-voltage protection
Included
Overcurrent protection
Included
Short circuit protection
Included 800A at 500 microseconds
Over-temperature protection
Included
Under-temperature protection
Included auto-heater activation
Bluetooth security
PIN-protected unique PIN printed on battery top
Certifications and warranty
Certifications
Safety certifications
RoHS, CE, UN38.3
Industry memberships
NMEA, ABYC, NMMA, RVDA
Manufacturer warranty
11 years original owner, non-transferable
Warranty registration
Required within 90 days of purchase see Warranty tab or contact us
SKU
12300A-H
Recommended charger settings
Charger Configuration
Battery type selection
LiFePO4 or Lithium Iron Phosphate
Bulk voltage
14.4V
Absorption voltage
14.4V
Float voltage
13.8V
Equalization
Disable do not use
Temperature compensation
Disable BMS manages temperature internally
Recommended charge current
50A standard up to 200A maximum
Compatible charger types
LiFePO4-compatible MPPT solar controllers, inverter/chargers, DC-DC chargers, shore power converters
Standard lead-acid, AGM, or gel battery chargers are not compatible with LiFePO4 chemistry and may cause damage or undercharging. Verify your charger or converter supports LiFePO4 voltage parameters before connecting. Many older RV converters require a lithium-compatible upgrade board or replacement unit.
FAQs
Will this battery fit in my existing Group 31 battery tray on my boat or RV?
In most cases, yes. The battery base measures 13.75 inches long and 7.63 inches wide, with a height of 10.00 inches (10.50 inches with bolt terminals). These dimensions fit the standard Group 31 footprint used in the majority of marine battery boxes and RV battery compartments. Verified installations include Winnebago View, Winnebago Solis, Airstream 27 GT, Thor Sequence, Coachmen Leprechaun, Jeanneau 36.2, Hallberg-Rassy sailboats, trawlers, and numerous travel trailers and 5th wheels. Some installations required trimming the plastic handles or sourcing slightly longer cable leads. Measure your compartment before ordering and compare against the specifications listed in the Tech Specs tab.
How does the Bluetooth security PIN work?
Each battery ships with a unique security PIN printed on the top of the battery case. When connecting to the Epoch Li-Ion App for the first time, you will be prompted to enter this PIN. Once entered, the connection is established and the battery is protected against unauthorized Bluetooth access. The PIN prevents other people from connecting to your battery, monitoring it, or altering its configuration settings. The PIN is permanent and cannot be changed or deleted. Photograph the PIN when you install the battery and keep it somewhere accessible for future reference.
What does the Bluetooth app show and does it replace a shunt?
The free Epoch Li-Ion App (iOS and Android) displays real-time state of charge as a percentage, individual cell voltages, total pack voltage, current amps flowing in and out, battery temperature, and a log of BMS events. When two or more batteries are connected in parallel, the app detects the configuration and displays them together as a bank. Many customers find the app provides sufficient monitoring without a dedicated external shunt. For customers running a full Victron system with a Cerbo GX, a SmartShunt is recommended alongside the app for whole-system visibility.
Can I charge this battery in freezing temperatures?
Yes. The built-in self-heating element enables charging at temperatures as low as -4 degrees Fahrenheit (-20 degrees Celsius). The heater activates automatically through the BMS when the battery temperature drops below the safe charging threshold. The heater draws approximately 10 to 11 amps from the incoming charge current solar, shore power, or an alternator-connected DC-DC charger must be connected for the heater to operate. The battery does not discharge itself to generate heat. Discharge is also rated to -20 degrees Celsius. Optimal discharge performance occurs between 59 and 95 degrees Fahrenheit (15 to 35 degrees Celsius).
Can I store this battery in an unheated space over winter?
This is an important limitation to understand before purchasing. The self-heating element in this battery cannot be disabled. If the battery is stored in a location where temperatures drop below freezing and it is not connected to a charge source, the heater will activate automatically and draw power from the battery until it discharges completely. For cold-weather storage without a charge connection, three options are recommended:
Connect the battery to a trickle charge source such as a solar panel or shore power to keep it topped up
Remove the battery from the vessel or vehicle and store it indoors at 50 to 100 percent state of charge
If leaving it in place, charge it fully before winter and recharge every three months as recommended by the manufacturer
Storage temperature range is 32 to 95 degrees Fahrenheit (0 to 35 degrees Celsius).
Is this battery compatible with Victron MPPT, MultiPlus, or Cerbo GX?
Yes, this battery works with Victron MPPT solar charge controllers, MultiPlus and Quattro inverter/chargers, Orion DC-DC chargers, SmartShunt, and Cerbo GX using standard LiFePO4 charge parameters. Set the charger to LiFePO4 mode with 14.4V Bulk and Absorption, 13.8V Float, and disable equalization and temperature compensation. The 12300A-H Essential Series does not include Victron CANBUS communication. This means the battery does not communicate directly with the Cerbo GX to report state of charge or charge limits. A Victron SmartShunt provides system-level monitoring alongside the Epoch app for Essential Series installations.
What size inverter can I run from a single 300Ah battery?
The 12300A-H has a 200A continuous BMS, which limits practical continuous output to approximately 2,560 watts at 12.8 volts. A 2,000-watt pure sine wave inverter pairs well with a single battery for most marine and RV loads including refrigeration, lighting, phone and device charging, CPAP machines, and small kitchen appliances. For a 3,000-watt inverter, two batteries in parallel are recommended to stay within BMS current limits under sustained load. For high-draw appliances such as air conditioners or microwave ovens, plan for two or more batteries in parallel.
Can I connect two or more of these batteries in parallel?
Yes. Up to four batteries can be connected in parallel for a 1,200Ah bank at 12V. Before connecting batteries in parallel, charge each battery individually to the same state of charge to minimize inrush current between units. Use equal-length cables from each battery to a common bus bar to ensure balanced current sharing. It is not recommended to parallel batteries of significantly different ages or cycle counts, as differences in internal resistance can cause unequal load distribution. Using batteries of the same model and similar charge history produces the most consistent parallel performance.
Does my existing boat charger or RV converter need to be replaced?
Only if your current charger does not support LiFePO4 voltage parameters. Many older RV converters charge to 13.6V or lower designed for lead-acid or AGM and will undercharge a LiFePO4 battery over time. Marine chargers vary by manufacturer and model. Check that your charger can be set to 14.4V Absorption and 13.8V Float with equalization disabled. If not, options include replacing the charger with a lithium-compatible unit, installing a compatible upgrade board for your existing converter, or adding a dedicated DC-DC charger for the lithium bank. Contact us if you need help identifying the right charging solution for your setup.
How much solar do I need to fully recharge this battery in a day?
Starting from 50 percent state of charge (approximately 150Ah to replace), at 4 to 5 peak sun hours per day, a 600 to 800 watt array with a quality MPPT charge controller configured for LiFePO4 provides a reliable full recharge. Customers confirm that 400 watts of solar covers moderate daily consumption with the battery maintaining a good state of charge through normal boondocking or at-anchor use. For winter charging, cloudy climates, or systems with higher daily consumption, 1,000 to 1,200 watts of solar provides more reliable results.
What cells are used inside this battery?
The 12300A-H is built using EVE prismatic LiFePO4 cells. Epoch Batteries has a long-established supply relationship with EVE and has been involved in component selection including the prismatic cells, BMS, and heating components since the inception of the product. Epoch publishes the cell manufacturer as part of its product transparency policy, which is not standard practice among all battery brands in this market segment.
How do I register my warranty and what does it cover?
Warranty registration is required within 90 days of purchase. For full registration details and warranty terms, see the Warranty tab or contact us and we will guide you through the process. The 11-year warranty applies to the original owner and is non-transferable. It covers defects in materials and workmanship under normal operating conditions within manufacturer specifications. It does not cover damage from gross negligence, accident, collision, abuse, incorrect installation, or use outside the specified voltage, temperature, and current parameters.
Is there a manual included and where can I find product documentation?
A printed manual is not included in the box. The battery arrives with Bluetooth app QR codes for iOS and Android on the spec sheet. The full product manual and spec sheet are available contact us and we will send the documentation directly. If you have questions during setup or installation, contact us and we will assist with charge profile configuration, parallel wiring, and compatibility questions.
