Next Generation Ultra Slim XL 1250Ah LiFePO4 Battery | 380A BMS

🔋 CUSTOM LITHIUM NEXT GENERATION ULTRA SLIM XL 1250AH LiFePO4 BATTERY – AUSTRALIAN MADE

1250Ah • 12.8V LiFePO4 • 380A Continuous Discharge • Modified Heltech BMS • Low-Temperature Protection • 102kg • 7 Year Warranty

The Custom Lithium Next Generation Ultra Slim XL 1250Ah Battery is designed for exceptionally high-capacity off-grid electrical systems where extended runtime and substantial stored energy are the priority.

With an enormous 1250Ah of LiFePO4 capacity in a purpose-built aluminium enclosure, this battery is aimed at serious caravan, motorhome, canopy, remote-work and high-demand off-grid installations where a conventional multi-battery bank would consume significant space.

A stated 380A continuous discharge capability, premium A-grade automotive LiFePO4 cells, modified high-current Heltech BMS and active cell balancing provide the foundation for demanding 12V systems and appropriately engineered high-power inverter installations.

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⭐ KEY FEATURES

🔋 Massive 1250Ah LiFePO4 Capacity
Provides exceptional stored energy for large off-grid electrical systems and applications requiring extended operation between charging opportunities.

⚡ 380A Continuous Discharge
High-current capability supports demanding 12V loads and appropriately designed high-power inverter systems.

🧠 Modified Heltech High-Current BMS
The supplied product information specifies a modified Heltech BMS designed to provide protection against overheating, over-discharge and low-temperature charging conditions.

❄️ Low-Temperature Cut-Off Protection
The BMS is stated to incorporate low-temperature cut-off protection to help protect the battery when temperatures are unsuitable for charging.

⚖️ Active Cell Balancing
The integrated active balancer helps manage individual cells and maintain consistent battery performance.

🔋 Premium A-Grade Automotive LiFePO4 Cells
Built using premium lithium iron phosphate cells for demanding mobile and off-grid applications.

🛡️ Aluminium Enclosure
The custom aluminium housing is designed to protect the battery cells and internal components while packaging very high capacity into a purpose-built enclosure.

🚙 Designed for Rugged Touring Conditions
Internal components are insulated against vibration to help protect the system during corrugated-road and remote-area travel.

🧪 Individually Bench Tested
Each battery is individually bench tested before supply as part of Custom Lithium's quality-control process.

🇦🇺 Australian Made
Built in Brisbane and supplied as a certified Australian Made product.

🛡️ 7 Year Warranty
Backed by a full 7-year manufacturer warranty.

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🚐 DESIGNED FOR SERIOUS OFF-GRID SYSTEMS

The Ultra Slim XL 1250Ah is intended for installations where very high battery capacity is required without resorting to multiple conventional battery cases and interconnecting battery banks.

Suitable applications can include:

• Large caravans
• Motorhomes & RVs
• High-capacity 4WD canopy systems
• Remote-work vehicles
• Mobile trade installations
• Extended off-grid touring systems
• High-demand inverter-based electrical systems
• Applications requiring long runtime between recharge opportunities

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🔩 IMPORTANT MOUNTING REQUIREMENTS

Due to the size and approximately 102kg weight of the Ultra Slim XL battery, Custom Lithium recommends that the battery be hard mounted directly to the vehicle or canopy floor.

The supplied installation guidance allows the battery to be mounted either:

• Flat on its broad face surface
• On one of its longer sides, in accordance with the manufacturer's installation guidance

This arrangement allows the battery mass to be fully supported by the vehicle or canopy floor rather than suspended from an unsupported mounting system.

⚠️ At approximately 102kg, this battery creates a substantial dynamic load in a moving vehicle. The supporting structure and mounting hardware must be engineered to safely withstand braking, cornering, vibration and rough-road loads.

⚠️ Installation by a qualified auto electrician is recommended by Custom Lithium.

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⚡ POWER FOR HIGH-DEMAND EQUIPMENT

With 1250Ah of lithium capacity and substantial continuous-current capability, the Ultra Slim XL can support compatible equipment including:

• ❄️ Multiple 12V fridges & freezers
• 💡 Vehicle & camp lighting
• 📡 Starlink
• 💻 Computers & electronics
• 📷 Cameras & charging equipment
• 💨 Air compressors
• 🛠️ Tools & battery chargers
• ☕ Coffee machines through a suitable inverter
• 🍳 Induction cooking through an appropriately engineered inverter system
• 🔌 Compatible 240V appliances through a suitable inverter

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🔋 PREMIUM LiFePO4 CELL TECHNOLOGY

The battery is constructed using A-grade automotive LiFePO4 cells combined with a modified high-current Heltech BMS and active cell balancing.

The supplied product information describes LiFePO4 as suitable for demanding mobile and off-grid environments where safety, reliability and consistent electrical performance are important.

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📊 TECHNICAL SPECIFICATIONS

Capacity: 1250Ah

Nominal Voltage: 12.8V

Continuous Discharge: 380A

Recommended Charge Current: 130A

Charge Voltage: 14.2–14.6V

Absorption / Float Voltage: 13.4–13.6V

Low-Voltage Cut-Off: 10.5V

Operating Temperature: 0°C to 60°C

Terminals: M10

Battery Dimensions: 803mm L × 487mm H × 163mm W as supplied

Overall Dimensions: 830mm L × 487mm W × 163mm H as supplied

Weight: Approx. 102kg

Battery Chemistry: LiFePO4

Cells: Premium A-Grade Automotive LiFePO4

BMS: Modified Heltech High-Current BMS

Cell Balancing: Active Balancer

Low-Temperature Cut-Off: Yes – exact threshold not supplied

Enclosure: Aluminium

Warranty: 7 Years

Manufactured: Brisbane, Australia

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⚡ 380A CONTINUOUS DISCHARGE

The stated 380A continuous discharge capability provides substantial current availability for demanding auxiliary electrical systems.

This allows the Ultra Slim XL to form part of an appropriately engineered high-power inverter system, provided the inverter, DC cabling, fuse protection, isolation and terminal connections are correctly designed.

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🔌 CHARGING REQUIREMENTS

The supplied technical specification lists a recommended charge current of 130A.

• Recommended Charge Current: 130A
• Bulk / Charge Voltage: 14.2–14.6V
• Absorption / Float Voltage: 13.4–13.6V

Compatible lower-output charging equipment can also be used, although recharge times will increase accordingly.

For a battery bank of this capacity, charging-system design is particularly important. A complete installation may incorporate:

• Vehicle DC-DC charging
• Large solar capacity
• 240V mains charging
• Multiple appropriately coordinated charging sources

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❄️ LOW-TEMPERATURE BMS PROTECTION

The supplied product information states that the modified Heltech BMS incorporates low-temperature cut-off protection.

This is intended to provide additional battery protection where charging conditions fall outside suitable temperature limits.

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🇦🇺 AUSTRALIAN MADE

Custom Lithium states that the Next Generation Ultra Slim XL battery is Australian Made certified and manufactured in Brisbane.

Each battery is individually bench tested before supply and backed by a 7-year manufacturer warranty.

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🛠️ INSTALLATION CONSIDERATIONS

• Approximate battery weight: 102kg
• Hard mounting directly to the vehicle or canopy floor is recommended
• Battery may be positioned flat or on one of its longer sides as specified by Custom Lithium
• Supporting structure must carry the full battery mass and dynamic vehicle loads
• Allow adequate clearance for M10 terminals and high-current cabling
• Correct cable sizing, fuse protection and isolation are essential
• Professional installation by a qualified auto electrician is recommended

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❓ QUICK FAQ

How much capacity does the Ultra Slim XL 1250Ah provide?

The battery provides a stated 1250Ah at 12.8V nominal, making it a very high-capacity solution for large off-grid electrical systems.

How should the 1250Ah battery be mounted?

Custom Lithium recommends hard mounting it directly to the vehicle or canopy floor, either flat on its broad face or supported on one of its longer sides in accordance with the manufacturer's installation guidance.

Can it run a large inverter?

It can form part of an appropriately engineered high-power inverter system. The supplied continuous discharge rating is 380A, so inverter selection must consider actual DC current demand, surge requirements, cabling, fuse protection and BMS limitations.

Does it have low-temperature protection?

Yes. The supplied product information states that the modified Heltech BMS incorporates low-temperature cut-off protection. The exact temperature threshold has not been supplied.

What charging profile should I use?

The supplied specifications call for a 14.2–14.6V charge voltage and 13.4–13.6V absorption/float voltage.

What charge current is recommended?

The supplied recommended charge current is 130A. Lower-output compatible charging equipment can also be used, but recharge times will increase further.

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🔋 1250AH OF EXTREME OFF-GRID ENERGY STORAGE

With 1250Ah of LiFePO4 capacity, 380A continuous discharge capability, a modified Heltech BMS, active balancing and a purpose-built aluminium enclosure, the Custom Lithium Next Generation Ultra Slim XL 1250Ah is designed for serious electrical systems where very large stored energy capacity is the priority.

Extreme capacity. High-current capability. Australian made.