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SunWell Energy

20.48kWh 51.2V Low-Voltage Stackable LiFePO4 Battery

20.48kWh 51.2V Low-Voltage Stackable LiFePO4 Battery

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Designed for scalable residential and commercial banks, the 20.48kWh 51.2V Low-Voltage Stackable LiFePO4 Battery packs LiFePO4 storage into a modular stackable enclosure. The modular stackable design installs with basic cabling and no special tools, fitting tight equipment spaces. Built-in protection guards every cell against over-charge, over-discharge, over-current and short circuits.

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20.48kWh 51.2V Low-Voltage Stackable LiFePO4 Battery — Technical Specifications
MODELSW-SS-51LVP4
Electrical Characteristics
Rated Voltage51.2Vdc
Energy Storage20.48kWh
Cycle Life25±2°C, 0.5C/0.5C, EOL70%≥6000
Months Self Discharge≤2%
Charge Voltage56V
Max. Charge Current100A
Max. Discharge Current100A
Discharge Cut-Off Voltage43.2Vdc
Charge Cut-Off Voltage58.4Vdc
Environment
Charge Temperature0°C to 50°C@60±25% Relative Humidity
Discharge Temperature-20°C to 50°C@60±25% Relative Humidity
Storage Temperature-20°C to 50°C@60±25% Relative Humidity
Mechanical
IP ClassIP65
Case TypeStand Stack
Product Dimension(L×W×H)640×205×1581mm
Package Dimension(L×W×H)760×335×450mm×4; 705×395×240mm
Net Weight14kg + 48kg×4
Gross Weight21kg + 53kg×4
Communication
Protocol (Optional)CAN/RS485/RS232
MonitoringBluetooth/WLAN Optional
Certificates
CellUN38.3, MSDS
PACKUN38.3, MSDS, IEC62619, CE, UL1973, UL2054
Others15S (48Vdc) models also available

Features

  • LiFePO4 chemistry delivers safe, long-lasting power. The cobalt-free cells resist thermal runaway and hold capacity through deep daily cycling, rated for 6000+ cycles at high state of health.
  • Modular stackable design scales by adding modules. Units stack to build a larger bank with no rewiring, growing from one module to a full backup system.
  • A multi-protocol BMS guards every cell. It tracks per-cell voltage, current and temperature, balances cells and blocks over-charge, over-discharge, over-current and short circuit, talking to inverters over CAN/RS485.
  • Long service life cuts ownership cost. Rated for 6000+ cycles, it supports years of daily charge and discharge without premature replacement.
  • Wide operating range suits tough sites. It discharges from -20°C to 50°C and handles up to 100A continuous current, staying stable in unconditioned indoor and sheltered spaces.
  • Parallel-ready design grows with you. Add more units on the same bus to expand capacity while keeping the existing inverter and cabling.

Applications

  • Residential Backup: Keeps essential home circuits such as lighting, Wi-Fi, and refrigeration running during grid outages as part of a daily-cycling storage system.
  • Small Commercial Storage: Supports offices, shops, and workshops with compact stacked storage that fits utility rooms without sacrificing floor space.
  • Solar Self-Consumption: Pairs with hybrid inverters to store excess daytime PV and release it in the evening, raising the share of solar you actually use.
  • Off-Grid Power: Supplies independent energy for cabins, kiosks, and remote sites where grid connection is unavailable or unreliable.
  • Peak Shaving: Discharges stored energy during high-rate periods to reduce demand charges for small businesses on time-of-use tariffs.
  • Scalable System Expansion: Acts as a building block that parallels with more units to grow capacity as energy demand increases.

Battery Safety & Protection

The SW-SS-51LVP4 is built around Lithium Iron Phosphate (LiFePO4) cells, a chemistry valued for thermal stability and a low risk of thermal runaway relative to other lithium types. The cells are housed in an IP65-rated stand-stack enclosure that guards against dust and water ingress, making it suitable for indoor and semi-sheltered utility installations.

For system protection, the unit uses a battery management system together with breaker-level protection to guard against fault conditions during charge and discharge. Optional Bluetooth and WLAN monitoring let installers check status remotely, while certifications including UN38.3, MSDS, IEC62619, CE, UL1973, and UL2054 confirm transport and safety compliance.

Performance & Lifecycle Advantage

Rated at 20.48kWh with a 51.2V nominal output, the SW-SS-51LVP4 delivers stable energy through 100A continuous charge and discharge within a safe window set by a 43.2Vdc discharge cut-off and 58.4Vdc charge cut-off. Its compact 640×205mm footprint and stackable form factor make efficient use of limited installation space.

The LiFePO4 chemistry provides a long design life of 6000 cycles at 70% capacity retention under 25±2°C, 0.5C conditions, supporting years of daily cycling. With ≤2% monthly self-discharge and a lighter, lower-maintenance profile than lead-acid alternatives, it offers dependable long-term value for residential and small commercial storage.

Warranty

LiFePO4 batteries are backed by a 5-year warranty. If you experience any quality issues within the warranty period, please contact us and we will arrange a replacement or repair promptly.

Frequently Asked Questions

Will this battery work with my existing inverter?

The SW-SS-51LVP4 runs at a 51.2V nominal rating with CAN, RS485, and RS232 communication and is built for compatibility with most inverter brands on the market. Confirm your inverter's protocol during setup.

How much energy does it store and how long will it power my home?

It provides 20.48kWh of energy, the largest single tower in the LV range. Runtime depends on your load—high-demand households can cover extended evening use and backup, while very large draws deplete it sooner.

Can I add more capacity later?

Yes. This 4-module tower already delivers 20.48kWh, and it can be paralleled with further units to form even larger banks as your needs grow.

Is it safe to install and use at home?

The LiFePO4 cells sit in an IP65 stand-stack enclosure with BMS and breaker-level protection. It is rated for 0°C to 50°C charging and down to −20°C discharging.

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