eBoost Scalable Energy Storage System

The eBoost is a 16kWh stackable LFP battery designed for seamless integration with the Fortress Power Envy Duo 21 inverter — delivering reliable, scalable backup and off-grid energy.

eBoost Scalable Energy Storage System

Boost Performance. Boost Reliability.

The Fortress Power eBoost is a high-capacity, modular energy storage solution built for residential and light commercial applications. With 16kWh of usable energy per unit and the ability to scale up to 256kWh, eBoost is engineered to handle high load demands while offering the flexibility of stackable, parallel installations. Built-in heating elements, an IP65 weatherproof enclosure, and integration with the eWay wireway system allow for clean, all-weather installs.

When paired with the Envy Duo 21 inverter, the eBoost forms a fully integrated, whole-home energy storage system—ideal for backup power, energy independence, and more.

Applications

Residential

Light Commercial

Small Retail

FEATURES

  • Higher Capacity Per Module

    Delivers 16kWh of energy storage per unit—ideal for homes or businesses with higher load profiles or limited install space.

  • Expandable to 256kWh

    Easily scale your system by connecting up to 16 units in parallel, giving you the flexibility to grow as your energy needs evolve.

  • Integrated eWay Wireway System

    Built-in busbars, conduit ports, LED indicators, and an emergency shutoff make for clean, code-compliant installations with fewer external components.

  • All-Weather Durability

    IP65-rated and equipped with internal heating elements for reliable performance in extreme conditions, from freezing temperatures to high humidity.

  • Whole-Home Compatibility

    Pairs with the Fortress Power Envy Duo 21 inverter for seamless whole-home backup and energy management.

  • Quick Scale & Deploy

    Modular, scalable design with fast-connect hardware reduces install time and labor while maintaining a clean, professional appearance.

eWay vs. eWay Lite — Which One Do You Need?

The eBoost 16kWh can be paired with either the eWay or eWay Lite. Both enable fast installs, clean wiring, and seamless integration with Fortress Power Envy inverters — but each is designed for different system sizes and expansion plans.

eWay — Best for Multi-Battery & Whole-Home Systems

Choose the eWay if you want room to grow.

  • 750A Three-Terminal Busbar: Designed for paralleling multiple eBoost batteries for larger capacity systems.
  • Inverter-Ready Mounting Surface: Removable top cover allows you to mount the Envy Duo 21, Envy True 12, Envy 10, or Envy 8 directly on top.
  • Integrated Rapid Shutdown: Built-in RSD switch for battery, PV, and AC output to meet NEC code.
  • Smart Connectivity: Includes back knockouts, status LED indicator, and a Wi-Fi antenna port for Guardian monitoring.
  • Installer-Friendly Features: DIN-rail bracket allows clean, direct mounting of the Guardian (optional).

Recommended for: Whole-home backup, multi-battery scaling (up to 256kWh), VPP participation, and any installation expecting growth.

eWay — Best for Multi-Battery & Whole-Home Systems

Ideal when you only need one battery + one inverter.

  • 250A Battery Terminal: Perfect for single-battery configurations.
  • Compact, Cost-Optimized Design: No rear knockouts, no status indicator, and no Wi-Fi antenna port.
  • Side-Mounted Inverter Support: Designed for installations where the Envy inverter is mounted beside the battery, not stacked on top.
  • Power Switch Included: Provides safe system shutdown — however, RSD for battery cutoff is not integrated.

Recommended for: Smaller backup systems, off-grid cabins, sheds, RVs, and applications that will not add more batteries in the future.

Fortress Power highly recommends choosing the eWay if battery expansion is expected within the next two years.

For customers who want maximum flexibility, scalability, and clean stacked configurations, the eWay is the best long-term value.

1 eBoost 16kWh Battery with 1 Envy Inverter

2 eBoost 16kWh Batteries with 1 Envy Inverter

3 eBoost 16kWh Batteries with 1 Envy Inverter

6 eBoost 16kWh Batteries with 2 Envy Inverters

9 eBoost 16kWh Batteries with 3 Envy Inverters

PRODUCT INFORMATION

16kWh32kWh48kWh
GENERAL DATA
Weight353 lbs (160 kg)706 lbs (320 kg)912.6 lbs (414 kg)
Operating Temperature-4 ºF – 140 ºF (-20 ºC – 60 ºC)*
Ingress ProtectDegree IP65
CommunicationPCS CAN/RS485; Parallel:CAN
Dimensions (W*D*H)eWay : 22.84×10.18×9.39 in (580×258.6×238.5 mm) | Battery: 22.28×10.18×33.71 in (566×258.6×856 mm)
Warranty10 years
Mounting OptionsGround-Mount, Floor Standing, Wall-Hanged (Separate Accessory)
BATTERY SPECIFICATIONS
Maximum Units In Parallel1685
Cell TypeTier-1 Prismatic 16 Cell LFP
Nominal Capacity314Ah628Ah942Ah
Nominal Energy16.077kWh**32.154kWh**48.231kWh**
Nominal Voltage51.2V
Re-charge Voltage49V
Cut-off Voltage41.6V
Maximum Short-Circuit (A)2000A, 17ms
Operating Voltage Range41.6-57.6V
Closed-Loop Charge/Discharge180/250 A360/500 A540/750 A
Bulk/Absorption Charge55.2V
Max Charge/Discharge314A/10s628A/10s942/10s
Surge Discharge Power W18kW/10s36kW/10s48kW/10s
Cycle Life @ EOL 70%8000 Cycles
STANDARDS & CERTIFICATIONS
Safety StandardsUL1973, ANSI/CAN/UL9540:2023, UL9540A
ListingsCEC, LUMA, oGPE
TransportationUN38.3

* Performance will degrade at operating temperatures above 104 ºF (40 ºC)

** Values are based on measurements taken at 77 ºF (25 ºC) at beginning of life.

eForce Diagram

eBoost materials

VIDEO LIBRARY

eBoost ESS Video Library

4 Videos

PRODUCT COMPATIBILITY

Fortress Power Envy Inverters

Monitor and control your eBoost ESS. Anywhere! Anytime!

✅ Monitor Performance of Each Battery

✅ Update Firmware Over The Air

✅ Participate in Virtual Power Plant Programs