Skip to content
Contact Us Price Match Guarantee FAQs Why Buy From Us About Us Customer Reviews Installer Program Build Your System
BigBattery ETHOS 48V 5.1kWh LiFePO4 Home Battery Backup

BigBattery ETHOS 48V 5.1kWh LiFePO4 Home Battery Backup
$1,250.00 - $1,250.00
$1,250.00
$1,250.00 - $1,250.00
$1,250.00
✓ Authorized BigBattery Dealer
✓ Lowest Price Match Guarantee
✓ FAST & FREE Shipping: In Stock Ready To Ship
✓ Questions? Talk to a BigBattery Expert: 1-303-876-7654

Login for Exclusive Member Pricing.
Not a member? Create a Free Account.

5.12kWh · 51.2V · LiFePO4

BigBattery ETHOS 48V 5.12kWh Stackable Battery Module

One ETHOS module is 51.2V and 100Ah/5.12kWh — the base building block of BigBattery's stackable home battery system, sold individually to add to an existing ETHOS bank or to start a new one alongside an ETHOS Control Box.

It ships in the same IP65-sealed, UL9540/UL9540A/UL1973-listed enclosure as every other ETHOS module, so capacity added later matches what you already own exactly.

BigBattery ETHOS 48V 5.12kWh Stackable Battery Module
12-Year Warranty*
Lowest Price Guarantee
Authorized BigBattery Dealer
Free Shipping
0% APR Financing
Expert Support: (303) 876-7654

Why the ETHOS System

Stackable to 16 Modules Per Control Box

Every ETHOS module is the same 51.2V / 100Ah building block — start with what you need and add modules later without replacing what you already own.

300A Peak Discharge

A 300A peak for 5 seconds covers inverter surge and motor-start loads that a continuous-only rating would trip on.

Wide Operating Temperature Range

Rated to charge from 32°F to 113°F and discharge from -4°F to 140°F, with best performance between 59°F and 95°F.

IP65 / NEMA 4X Sealed Enclosure

Sealed against dust and water intrusion for garage, shed, or outdoor-adjacent installs.

CANBus / RS485 System Communication

Modules talk to the ETHOS Control Box and to each other over CANBus/RS485, the same protocol most hybrid inverters expect for a coordinated battery bank.

UL9540, UL9540A, UL1973 Listed

Certified to the UL standards that matter for a residential energy storage installation, plus UN38.3 for transport.

What's Included

What's included: BigBattery ETHOS 48V 5.12kWh Stackable Battery Module

What You Get

  • 1 × BigBattery ETHOS 48V 5.12kWh Stackable Battery Module
  • Documentation

Requires an ETHOS Control Box (sold separately) and at least one additional module to operate — the control box needs a minimum of 2 modules connected.

Full Specifications

Model BigBattery ETHOS Stackable Module
Nominal Voltage 51.2V
Capacity 100Ah / 5.12kWh
Battery Chemistry LiFePO4
Cycle Life 3,500–5,000 cycles (80% DoD, 0.5C)
Continuous Discharge / Charge (single module) Not published by BigBattery for this specific configuration — published only at the 2-module-minimum system level
Peak Discharge 300A for 5 seconds
Max Charge Current 200A
Charge Temperature Range 32°F to 113°F (0°C to 45°C)
Discharge Temperature Range -4°F to 140°F (-20°C to 60°C)
Optimal Operating Range 59°F to 95°F (15°C to 35°C)
Weight 273 lb
Dimensions 26.5"W × 43.3"H × 6.7"D
Ingress Protection IP65 / NEMA 4X
Communication CANBus / RS485
Max Parallel Up to 16 modules per ETHOS Control Box
Warranty 12 years
Certifications UL9540, UL9540A, UL1973, UN38.3

Authorized BigBattery Dealer

We sell genuine BigBattery products backed by BigBattery's own warranty.

Lowest Price Guarantee

Find it cheaper from another authorized dealer? Call (303) 876-7654 before you order.

Real Support, Not a Ticket Queue

Sizing a battery bank or system? Call (303) 876-7654 and talk to a person.

BigBattery ETHOS 48V 5.12kWh Stackable Battery Module: Frequently Asked Questions

Can I buy just one module, or do I need to buy a full stack?
You can buy a single module, but the ETHOS Control Box requires a minimum of 2 modules to operate — so a single module only works as an addition to a system that already has at least one other module installed.
What do I need besides the battery modules to build a working system?
An ETHOS Control Box, which is the hub the modules connect to and what talks to your inverter over CANBus/RS485. It's sold separately.
Is this compatible with my inverter?
The ETHOS system communicates over CANBus/RS485, which is the protocol most hybrid inverters designed for stackable LiFePO4 banks expect. Confirm compatibility with your specific inverter model before ordering — call (303) 876-7654 and we can help you check.
How cold can it get before this stops charging?
Charging is rated down to 32°F (0°C); below that, the BMS will not accept a charge, which is normal for LiFePO4 chemistry without a self-heating feature. Discharge is rated down to -4°F (-20°C).
What certifications does the ETHOS system carry?
UL9540, UL9540A, and UL1973 for the energy storage system itself, plus UN38.3 for transport — the certifications that typically matter for a residential installation and permitting.
Do you offer financing or price matching?
Yes. We offer 0% APR financing options through Affirm at checkout, and our Lowest Price Guarantee applies — if you find this product cheaper at another authorized BigBattery dealer, call us at (303) 876-7654 before you order and we'll take care of it.
Renewable Outdoors LLC BBB Business Review