Rubix Giga Stack Series RGS51205 10.5kWh 205Ah 48V LiFePO4 Battery

The Rubix Giga Stack Series RGS51200 is a 48V LiFePO4 battery delivering 10.5kWh of usable capacity in a heavy-duty, stackable enclosure engineered for residential and light commercial energy storage systems that demand high surge output and long service life. Built on prismatic lithium iron phosphate cells with an integrated BMS, 500A fuse, and touchscreen LCD, the RGS51200 combines the cycle depth of a serious solar battery storage platform with a 1,000A microsecond surge rating that handles inrush-heavy loads without flinching.

Key specifications

• Energy capacity: 10.5kWh (48V nominal / 205Ah; actual voltage 51.2V at 20% SOC)
• Cycle life: 4,000 cycles at 100% DOD; 6,000 at 80% DOD; up to 8,500 at 50% DOD — 80% capacity retained at end of rated life
• Scalability: up to 4 units per stack; horizontal installation with included base unit
• Discharge output: 140A continuous (7.2kW); 300A surge at 10ms; 1,000A surge at 0.5 microseconds
• Certification: UL9540A Pending; UN38.3 transport certified

LiFePO4 chemistry built for daily cycling

LiFePO4 (lithium iron phosphate) chemistry is the reason buyers replace lead acid batteries once and don't look back. The RGS51200 is rated for 8,500 cycles at 50% depth of discharge — the realistic range for a daily-cycling home energy storage system — before capacity drops below 80%. That's a service horizon measured in decades, not years, without the venting requirements, watering schedules, or sulfation risk that come with flooded lead acid. Prismatic cells with welded busbar connections maintain pack consistency throughout the battery's rated life.

Key Applications

• Residential solar backup: Pairs with a 48V hybrid inverter to store daytime solar generation and carry critical loads through the night or during grid outages.
• High-inrush load environments: The 1,000A microsecond surge rating handles the startup draw of well pumps, HVAC compressors, and power tools without tripping protection.
• Scalable home ESS: Start with one 10.5kWh unit and expand the stack as energy needs grow — without replacing existing hardware or adding separate enclosures.
• Off-grid properties: The stackable form factor and built-in handles allow a large LiFePO4 deep cycle battery bank to be configured and repositioned indoors without additional racking.
• Emergency preparedness: Sized to power essential household loads through extended outages when paired with solar or AC charging.

Surge protection and built-in BMS safeguards

• 500A fuse and 150A circuit breaker provide dual-layer overcurrent protection at the pack level.
• Low voltage protection: BMS low volt cutout activates at 46V (±1V) to guard against deep discharge; inverter low battery cutout threshold is 48V.
• Thermal cutoffs: Charging halts at 32°F (0°C); BMS disconnects above 135°F (57.2°C) — protecting the pack across the full installation environment range of 32°F–120°F.
• Impactive cell balancing at up to 1.1A actively equalizes individual cell voltages to preserve long-term capacity and prevent premature degradation.
• Touchscreen LCD displays SOC, pack voltage, charge/discharge amps, balancer status, individual cell voltages, and fault log — no external monitoring device required.

Inverter and system compatibility

The RGS51200 is designed for 48V inverter systems running a LiFePO4 charging profile: recommended absorb voltage 56.8V (57.6V max for solar-only systems), float at 54.4V, recommended cycling range 51–56.5V, absorb done threshold 10A per battery over a 10-minute absorb done period. The battery must be installed horizontally using the included base unit indoors only — IP50 rated, not suitable for outdoor installation. Required clearances: 3 in. from walls, 4 in. between parallel stacks, 6 in. between the top of the stack and wall-mounted solar equipment, and 4 ft. from any water source or conductor. Maximum 4 batteries per stack. Battery weight: 199 lbs.

Why choose the Rubix Giga Stack Series RGS51200?

The Rubix Giga Stack Series RGS51200 is built for buyers who need more than long cycle life from a 48V battery bank — they need surge headroom. The 1,000A microsecond surge rating, dual-layer overcurrent protection (500A fuse plus 150A breaker), and 8,500 rated cycles at 50% DOD position the RGS51200 above standard residential LiFePO4 options where high-inrush loads are part of the daily load profile. Indented handles and a universal wheel make it practical to move and install without additional equipment — a detail that matters when you're stacking 199-lb units.