Discover Energy 48-48-5120-H 5kWh 48V AES Rack-Mount Energy Storage System LiFePO4 Battery

The Discover Energy 48-48-5120-H is a 48V 100Ah LiFePO4 battery engineered for residential off-grid solar and whole-home backup power applications. Housed in a standard 19-inch 3U rackmount chassis, this 5.12 kWh energy storage module ships with 100% usable depth of discharge, a fourth-generation high-current BMS, and integrated self-heating — making it one of the more installation-ready rack-mount lithium batteries available for North American residential systems.

Key specifications

• Nominal voltage: 51.2V (48V system)
• Nominal energy / rated capacity: 5.12 kWh / 100Ah (1-hour rate)
• Usable depth of discharge: 100%
• Chemistry: LiFePO4 (lithium iron phosphate) — inherently stable cathode chemistry with no thermal runaway risk associated with NMC or NCA cells
• Max. continuous charge / discharge current: 70A / 70A; max. 1-hour rate: 95A / 95A
• Peak discharge current (3 sec): 218A RMS (2.2C surge)
• Round-trip efficiency: up to 98%
• Self-discharge: <3% per month @ 77°F (25°C)
• Charge temperature: 39.2°F to 125.6°F (4°C to 52°C); internal heater active from 1.4°F to 46.4°F (-17°C to 8°C)
• Discharge temperature: 1.4°F to 125.6°F (-17°C to 52°C)
• Dimensions (L × W × H): 19.6 × 17.3 × 5.3 in. (497.3 × 439.2 × 133.5 mm); weight: 97 lbs. (44 kg)
• Terminal: Amphenol SurLok Plus; cell configuration: 16s1p; enclosure: galvanized steel, IP20
• Certifications: UL1973, UL9540, UL9540a, IEC 62619, CE
• Warranty: 10-year limited with energy performance guarantee

Full capacity, no derating required

Most lithium batteries are derated to 80–90% usable capacity to preserve cycle life. The 48-48-5120-H is rated for 100% depth of discharge, meaning all 5.12 kWh is available to the load — not just on paper. This is enabled by the GEN-4 BMS, which actively manages cell balancing, low-voltage disconnect at 43.2V under load, and real-time charge rate optimization for up to 40% faster recharge from 0 to 100% state of charge compared to fixed-rate alternatives. For a home backup application, that translates directly into more runtime between charges and faster recovery from a deep discharge event.

Cold-weather and high-demand operation

The integrated self-heating element activates automatically between 1.4°F and 46.4°F (-17°C and 8°C), allowing the battery to accept charge in ambient conditions that would put a non-heated lithium battery into protection mode. On the discharge side, the GEN-4 BMS supports a peak surge current of 218A RMS for three seconds — 2.2C of the rated capacity — which provides headroom for motor-start loads such as well pumps, HVAC compressors, and refrigeration equipment without tripping the BMS.

Applications: off-grid solar and home backup

• Off-grid solar: Pairs with 48V solar charge controllers and off-grid inverters for cabins, rural properties, or full-time off-grid homes; 1C continuous charge rate means a full recharge from solar in approximately one hour under ideal conditions.
• Whole-home backup: Sized to carry essential loads through overnight or multi-hour outages; scalable to 184 kWh per LYNK II Gateway for larger backup requirements.
• Parallel expansion: Multiple modules connect via the LYNK Port for multi-battery BMS communication, linear scaling of charge/discharge capacity, and remote ON/OFF control through the LYNK II Gateway.
• Cold-climate installations: Self-heating enables operation at ambient temperatures as low as 1.4°F (-17°C) without external battery warmers.

System and charger compatibility

The 48-48-5120-H communicates with compatible inverter-chargers through the optional LYNK II Gateway, which supports CANopen, Serial CAN, J1939, and RV-C protocols for closed-loop charger configuration — enabling the charger to read real-time battery state of charge and temperature rather than relying on voltage-based estimation. Charge parameters: bulk and absorption at 55.2V, float at 53.6V, termination current 2.5A, recommended low-voltage disconnect at 48V. The battery uses Amphenol SurLok Plus DC terminals and is compatible with the AES Rackmount Battery Combiner (up to 6 modules) and the AES Slimline Enclosure for indoor or outdoor NEMA 3R installations. UL9540 and UL9540a listings support permitting as a battery energy storage system (BESS) throughout North America.

Why choose the Discover Energy 48-48-5120-H?

The Discover Energy 48-48-5120-H stands apart from comparably priced rack-mount LiFePO4 batteries in three areas that matter for demanding residential installations: integrated self-heating for cold climates, a 2.2C peak surge rating for motor-load support, and UL9540/UL9540a certification that streamlines AHJ permitting without third-party documentation. The 10-year warranty with an energy performance guarantee backs the longevity claim — not just the hardware. A1 SolarStore offers the 48-48-5120-H for buyers building a scalable, certified energy storage system on the Discover AES platform.