ABYSS® 48V125Ah Lithium Marine House Battery

Silent, high‑voltage power for electric propulsion and true generator‑free living aboard.

Meet the house battery that lets you cruise, anchor, and sleep without the drone of a genset. Built around a 51.2V LiFePO₄ pack and a robust marine BMS, this 6.4 kWh module is purpose‑engineered for electric propulsion and high‑demand DC/AC house loads—then sealed to IP67 so it actually belongs on a boat. It also speaks Victron natively over CAN, so your inverter/charger and GX devices coordinate charge limits and currents automatically for a clean, alarm‑free system.

Why choose this battery?

• Generator replacement: Pair with a Victron inverter/charger and you’ve got quiet AC overnighting, galley loads, and thrusters without burning diesel. Victron‑protocol CAN comms coordinate CVL/CCL during charging and taper current as the pack fills—exactly how it should work on a yacht.
  

• Serious energy density: 51.2 V × 125 Ah = 6,400 Wh in a single module designed for parallel scaling. (Series connections are not supported; keep modules at the same voltage before paralleling.) 
  

• Marine‑ready build: IP67 enclosure, CE/UN38.3 compliant, with integrated BMS protections for over/under‑voltage, over‑current, temperature, and short circuit.
  

• Victron protocol compatible: CANBUS + RS‑485 on board for plug‑and‑play integration with Victron inverters/chargers and GX devices.
  

• Installer‑friendly: Clearly labeled IN/OUT, charger/motor comm ports, remote/wire‑control switch option, and busbar guidance—including fuse and gauge recommendations.

Key specifications 

• Nominal voltage / capacity: 51.2 V / 125 Ah (LiFePO₄); Stored energy: ~6.4 kWh.

• Voltage range: ~40–57.6 V (CC/CV charging at 57.6 V). 

• Charge method/time: CC‑CV; typical full charge ≈ 4.5 h (standard).

• Cycle life: Long‑life deep cycle LiFePO₄ (manufacturer lists multi‑thousand‑cycle performance at 0.5C).

• Enclosure rating: IP67; Certs: CE, UN38.3.

• Dimensions (L×W×H): 650 × 360 × 210 mm; Approx. weight: ≈ 58.5 kg.

•  Comms: CANBUS & RS‑485; Victron protocol compatible. 

• System topology: Parallel‑only expansion; series not supported.

What it powers

• Electric outboards & pods (48 V class)

• Silent nights at anchor: air‑con (with inverter), galley, refrigeration, pumps, lighting

• High‑load DC systems: windlass, bow/stern thrusters (within BMS limits)

 
BMS Protection — Balance Settings

BMS Protection — Thresholds & Resets

PHYSICAL SPECIFICATIONS

• Dimensions: 25.6" x 14.2" x 8.2" in
• 650×360×210mm 
• Approximate Weight: 128.9 lbs (58.2 kg)
• Terminal Type: Energy Storage Connectors 200A plug
• IP Rating: IP67
• Cell Type: Cylindrical LiFePO4 cell
• Cell Holder: Yes

Abyss Battery® strives to make the safest and most reliable lithium iron phosphate batteries for the most demanding environments, that’s why our batteries are only made with certified components and used in applications around the world. All Abyss Lithium batteries conform to the standard entities and regulations listed below.

All Abyss Batteries meet and exceed The American Boat & Yacht Council (ABYC) standard for lithium ion batteries. The ABYC council is an organization that develops voluntary global safety standards for the design, construction, maintenance, and repair of recreational boats.

Abyss Battery®, Inc manufacturing process is compliant and licensed on a international level by TÜV Rheinland for Functional Safety as a result of exposure to harsh marine environments such as vibration, impact, ignition protection, water ingress and salt spray corrosion common on pleasure craft and boats. TÜV Rheinland stands for safety and quality in virtually all areas of business and life. TÜV Rheinland’s highly qualified experts test technical systems and products around the world, support innovations in technology and business, train people in numerous professions and certify management systems according to international standards. In doing so, the independent experts generate trust in products as well as processes across global value-adding chains and the flow of commodities. Since 2006, TÜV Rheinland has been a member of the United Nations Global Compact to promote sustainability and combat corruption.

UN/DOT 38.3: Lithium Battery Transportation

All Abyss Battery®, Inc. Lithium Batteries are required to pass section 38.3 of the UN Manual of Tests and Criteria, to ensure the safety of using products for our end users and for shipping purposes. We are proud of our investment to ensure our products have been UN38.3 certified.

T1 – Altitude Simulation
This is low pressure testing that simulates unpressurized airplane space (cargo area) at 15,000 meter altitude. After storing batteries at 11.6kPa for >6 hours, these criteria shall be met: no mass loss, leaking, venting, disassembly, rupture or fire, and voltage within 10% of pre-test voltage.

T2 – Thermal Test
This test covers changes in temperature extremes from -40°C to +75°C. Batteries are stored for 6 hours at -40°C (12 hours for large cells/batteries), then 6 hours at +75°C (12 hours for large cells/batteries), for a total of 10 cycles. Testing may be performed in a single chamber or thermal shock chamber, but less than 30-minute transitions shall be used.

T3 – Vibration
This test simulates vibration during transportation. Test is a Sine Sweep: 7Hz – 200Hz – 7Hz in 15 Minutes; 12 Sweeps (3 hours); 3 mutually perpendicular axes.

T4 – Shock
This test also simulates vibration during transportation. Test is a Half-Sine pulse: 150G/6ms for small cells/batteries; 50G/11ms for large cells/batteries; 3 pulses per direction; 6 directions (+/-z, +/-x, +/-y). Same pass criteria as T1.

T5 – External Short Circuit
This test simulates an external short to the terminals of the cell or battery. At temperature of +55°C, apply short circuit (<0.1ohm) across terminals. Maintain at least an hour after sample temperature returns to +55 +/-2°C. Pass criteria are: Case temperature does not exceed +170°C and no disassembly, rupture, or fire within 6 hours of test. Fuse, current limiting circuit, and venting mechanism activation are allowable.

T6 – Impact
This test is only applicable to primary and secondary cells. For cylindrical cells >20mm diameter, it simulates impact to case of cell. For cylindrical cells <20mm diameter and all other cell constructions, it simulates crushing of a cell. Pass criteria for any type is: Case temperature does not exceed +170°C & no disassembly or fire within 6 hours of test.

T7 – Overcharge
This test is for secondary or rechargeable batteries only. It simulates an overcharge condition on a rechargeable battery: 2x the manufacturer’s recommended charge current for 24 hours. Then battery shall be monitored for 7 days for fire or disassembly.

T8 – Forced Discharge
This testing simulates a forced discharge condition for primary and secondary cells only.

A B Y S S B A T T E R Y ® · M A R I N E L I T H I U M
10-Year Transferable Premium Warranty

Effective August 1, 2026. Applies to purchases made on/after the effective date; prior purchases remain covered under warranty terms in effect at time of purchase.

0 1 —WARRANTY OVERVIEW

Abyss Battery, Inc. (“Abyss”) warrants its marine lithium batteries to be free from defects in materials and workmanship for a period of ten (10) years from the original date of purchase. If an Abyss battery fails due to a defect in materials or workmanship during the warranty period, Abyss will, at its sole discretion, repair the battery or replace it with a new or equivalent current-production model. This warranty is fully transferable to subsequent owners upon registration, subject to the conditions in Section 04.

PRODUCT COVERAGE TERM COVERAGE
* Marine lithium batteries (12V, 24V, 36V, 48V, 72V) - 10 years from original purchase: Repair or replacement for manufacturing defects, at Abyss’s option.

* Reel batteries & chargers 2-year replacement, then 35% off through year 5 for manufacturing defects.

0 2 — WHAT IS COVERED

* Defects in materials or workmanship that occur during normal, intended marine use.
* Repair of the affected battery, or replacement with a new or equivalent current-production model, at Abyss’s sole discretion.
* If the original model has been discontinued, Abyss will replace it with the current equivalent model of comparable voltage, capacity, and specification.
* A repaired or replacement battery assumes the remaining warranty term of the original battery.
* 24/7 priority phone and chat support with Abyss battery experts.

0 3 — ACTIVATION: REGISTRATION

* Registration is required for 10-year coverage. Register within 90 days of purchase at abyssbattery.com or through the Abyss Battery App, with proof of purchase and battery serial number.
* Unregistered batteries with an original purchase receipt remain covered under the standard Abyss 5-Year warranty plan.
* Batteries that are not registered and have no proof of purchase carry no warranty coverage.
* For batteries with connected features, keeping firmware reasonably up to date through the Abyss Battery App is a condition of coverage for firmware-related failures.

0 4 — TRANSFERABILITY

*This warranty transfers to a subsequent owner — including when the battery is sold with a boat — provided that:

          - The transfer is registered online within 30 days of the sale;
          - The new owner provides the battery serial number; and
          - The original proof of purchase (or existing registration) is on file.

* There is no transfer fee. The warranty term is not extended by transfer; the new owner receives the balance of the
original 10-year term.

0 5 — EXCLUSIONS: WHAT IS NOT COVERED

*Damage from abuse, misuse, neglect, collision, fire, or submersion.

* Improper installation, improper charging, or use of charging equipment that does not fall within the specifications of a lithium charge profile or is not equipped with pulse wake up mode.

*Unauthorized modification, disassembly, tampering, or repair by anyone other than Abyss or its authorized service providers.

* Environmental damage, including flooding, extreme heat, freezing, or salt-water intrusion beyond rated protection.
* Normal wear, gradual capacity degradation within published cycle-life specifications, and cosmetic damage that does not affect performance.
* Loose or corroded terminals; jump-starting damage.
* Labor, removal, reinstallation, loss of use, towing, or other incidental costs.
* Batteries used in applications outside their published specifications, including non-marine commercial use.

0 6 — CLAIMS: HOW TO MAKE A CLAIM

* Contact Abyss support (phone, chat, or warranty@abyssbattery.com) with the serial number, proof of purchase or registration, and a description of the issue.
* Abyss will troubleshoot remotely first; many issues are resolved with firmware, charging, or configuration guidance.
* If a return is required, Abyss will issue an RMA with hazmat-compliant shipping instructions. Batteries must ship in original or hazmat-certified packaging via approved carriers.
* If a manufacturing defect is confirmed, Abyss covers return and replacement shipping. If no defect is found, the customer is responsible for shipping.
* Customers may optionally purchase a replacement up front to minimize downtime; a full credit is issued upon defect verification.

0 7 — TERMS & LIMITATIONS
This warranty applies under conditions of normal use. To the maximum extent permitted by law, Abyss disclaims all implied warranties beyond this written limited warranty and is not liable for incidental or consequential damages. Some states do not allow limitations on implied warranties or the exclusion of incidental or consequential damages, so these limitations may not apply to you. This warranty gives you specific legal rights; you may also have other rights that vary by state.