About Us Contact Us Shipping Easy Returns Privacy Terms of Service Happy Customers Solar System Size Calculator
Skip to content
Big Battery ETHOS 3x Expansion Kit Kits Big Battery

Big Battery ETHOS 3x Expansion Kit

BY: Big Battery | SKU: K0699 Availability: In Stock
$6,090.00

Notify me when back in stock

Found a Better Price?

Share it with us now and we will beat it. Get the best deal online - Guaranteed!

Call/Text Us: 877-556-3347
Live Chat With an Expert

  • Authorized Big Battery Dealer

    Full manufacturer warranty included

  • Free Shipping + No Sales Tax

    More savings on every purchase

  • Easy 30-Day Returns & Price Beat Guarantee

    Risk-free shopping + best price guaranteed

  • Lifetime Expert Support

    Dedicated help whenever you need it

Estimated Delivery Between

and .

Order within to get it by the earliest date.

Big Battery ETHOS 3x Expansion Kit

The Big Battery ETHOS 3x Expansion Kit is designed to enhance your existing ETHOS system by adding an additional 15.36kWh of lithium iron phosphate (LiFePO4) energy storage capacity. This all-in-one kit includes three 48V stackable battery modules, rack base, and necessary power and communication cables for seamless installation. Whether you're powering your home, business, or an off-grid setup, this expansion is built to deliver reliable, safe, and scalable energy.

BigBattery ETHOS 3x Expansion Kit Features

High-Capacity Storage

Expand your system with 15.36kWh of additional storage using three 5.12kWh LiFePO4 modules.

Compact Stackable Design

Space-saving form factor allows vertical stacking—ideal for tight utility rooms or garages.

Plug-and-Play Integration

Kit includes all parallel communication and power cables for fast setup with your existing ETHOS system.

Reliable LiFePO4 Chemistry

Safe, efficient, and long-lasting performance with lithium iron phosphate battery cells.

UL-Compliant Components

Components meet rigorous safety standards for home and commercial installations.

Placeholder Image

BigBattery ETHOS 3x Expansion Kit Applications

  • Residential Solar Storage - Store excess solar power for use at night or during grid outages, ensuring energy independence.
  • Commercial Power Backup - Keep critical systems running in small businesses during power interruptions and reduce downtime.
  • Off-Grid Living - Power remote homes or cabins with reliable energy storage that integrates with off-grid solar or wind systems.
  • EV Charging Energy Reserve - Use stored energy to support electric vehicle charging, reducing demand on the grid and saving costs.
  • Load Shifting & Peak Shaving - Lower energy bills by drawing from stored energy during peak utility rate hours.
  • Grid-Tied Battery Bank Expansion - Expand your existing on-grid battery setup for increased backup capacity or time-of-use optimization.
Placeholder Image

What's Included

Everything you need is included with your product.

  • 3 × 48V ETHOS 5.12kWh Stackable Battery Module
  • 1 × ETHOS RACK BASE
  • 2 × Ethos Parallel Power Cable 4.9 ft (1500mm)
  • 1 × Ethos Parallel Comm Cable 4.9 ft (150cm)

BigBattery ETHOS 3x Expansion Kit Specifications

Category Specifications
SKU KIT0699
GTIN-12 (U.P.C.) 850061252180
System Voltage 48V
Nominal Voltage 51.2V
Chemistry LiFePO4
kWh Capacity 15.36kWh
Ah Capacity 300Ah
Charging Voltage Range 55.6 - 57V
Max Charge Voltage 57V
Operating Voltage Range 48 – 57V
Suggested Low Voltage Cutoff 48 – 50.8V
Cell Configuration 16S 3P
Max Continuous Discharge Current 250A
Max Continuous Power 10240W
Max Discharge Peak Current 300A (Max 5 seconds)
Max Charge Current 200A
Charge Temperature Range 32°F - 113°F (0°C - 45°C)
Discharge Temperature Range -4°F - 140°F (-20°C - 60°C)
Optimal Discharge Temperature Range 59°F - 95°F (15°C - 35°C)
Storage Temperature Range (SoC >50%) -4°F - 113°F (-20°C - 45°C) (Max 6 months)
Weight 387 lb (175.5 kg)
Depth 6.7 in (170 mm)
Width 26.5 in (674 mm)
Height 59.8 in (1520 mm)
Max Connections Up to (16) parallel connections per control box
Protection Rating IP65
Communications CANBus / RS485

BigBattery ETHOS 3x Expansion Kit Video

Frequently-Asked Questions

Can I install this expansion kit without a Control Box?

No, this kit is an add-on and requires an existing ETHOS Control Box system.

How many modules can be added in total?

You can add up to 16 ETHOS modules (81.92kWh total) to a single Control Box.

Is the expansion kit user-installable?

Yes, with basic tools and knowledge. Still, professional installation is recommended for safety and warranty compliance.

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)