LG Chem RESU 12kWh Battery Storage System (51v with BMS)

The LG Energy Solution RESU12 12kWh Lithium Battery Storage System is a compact, high-performance home energy storage solution engineered for residential and small commercial environments. This battery runs on a 51-volt low-voltage system and includes an integrated Battery Management System (BMS) that protects the battery, monitors its performance, and ensures it works safely with your solar inverter.

Designed for flexible installation, the RESU12 supports wall-mounted or floor-standing configurations and can be installed indoors or outdoors, providing it is protected from direct rain, sunlight, and harsh weather exposure. Its sleek black-and-silver housing provides an attractive, modern aesthetic suitable for a wide variety of home and professional settings.

Built by LG Energy Solution (formerly LG Chem) - a global leader in lithium-ion and automotive battery technology - the RESU12 offers long-term reliability, safety, and proven performance. With a usable capacity of 11.7 kWh, it enables households to store excess solar generation for evening use, shift energy consumption to avoid high grid tariffs, and provide backup capability* during power outages. A high round-trip efficiency of up to 95% ensures maximum utilisation of stored solar energy.

The RESU12 incorporates advanced lithium-ion cells and an integrated Battery Management System (BMS) to maintain optimal performance, thermal stability, and long service life. The unit supports up to 119 A continuous charge/discharge current and provides 5 kW continuous power output, with peak output of 7 kW for 3 seconds, and 11 kW for 3 seconds in backup mode, exactly as specified in the datasheet. For increased storage capacity, the RESU12 can be expanded using the RESU-PLUS interface to combine up to two RESU units in a parallel configuration.

Highly compatible with a wide range of 48 V-class low-voltage inverter systems, the RESU12 offers simplified integration for both retrofit and new solar installations. Whether the goal is increased self-consumption, energy cost reduction, or dependable emergency backup*, the RESU12 delivers a robust and well-proven storage solution backed by a 10-year manufacturer warranty.

Backup functionality depends on the inverter model and installation configuration.

• 12 kWh total energy / 11.7 kWh usable capacity
• Nominal voltage: 51.8 V (48 V-class LV system)
• Advanced lithium-ion technology with long cycle life
• Up to 119 A continuous charge/discharge current
• 5 kW continuous output power
• 7 kW peak (3 seconds)
• 11 kW peak in backup mode (3 seconds)
• High round-trip efficiency (~95%)
• Parallel expansion supported via RESU-PLUS (up to 2 units total)
• Compact, wall-mountable or floor-standing design
• IP55 protection rating (weather-shielding required outdoors)
• Quiet, low-maintenance operation
• 10-year manufacturer warranty
• Wide compatibility with approved 48V low-voltage inverter systems

Specifications

• Battery Type: Lithium-ion
• Total Energy: 13.1 kWh
• Usable Energy: 11.7 kWh (approx. 90% DoD)
• Nominal Voltage: 51.8 V
• Voltage Range: 42.0 – 58.8 V
• Nominal Capacity: 252 Ah
• Continuous Discharge Power: 5,000 W
• Peak Output:
  • 7,000 W for 3 seconds
  • 11,000 W for 3 seconds (backup mode)
• Max Charge/Discharge Current: 119 A (166.7 A peak for 3 s)
• Round-Trip Efficiency: ~95% (25°C, C/3)
• Operating Temperature: –10°C to 50°C (Recommended 15°C–30°C)
• Protection Rating: IP55*
• Dimensions: 452 × 626 × 227 mm
• Weight: 98.5 kg
• Expandable: Up to 2 RESU units with RESU-PLUS
• Compatibility: 48 V low-voltage inverter systems (check approved inverter list)

*When installed outdoors, the battery must be sheltered from direct weather exposure to maintain long-term performance and warranty validity.

INSTALLER NOTICE: All LG Energy Solution RESU battery warranties must be activated by a certified installer with approved RESU training (mandatory since January 2019). Use only compatible inverters listed by the manufacturer to ensure full warranty coverage.

Code: RESU12