This is the Fortress Power eForce, a 48-volt, 28.8kWh LiFePO4 battery kit built for home and off-grid energy storage. It's a modular, stackable system — this listing covers the base kit, and the design allows you to scale up as your power needs grow.
Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
Expert Overview
Fortress Power built its reputation supplying energy storage to off-grid and grid-tied customers across North and Latin America. The eForce is their modular LiFePO4 platform designed for home battery banks that need to scale — from a single module up to a multi-battery tower. This 28.8kWh kit represents three of the 9.6kWh building blocks that make up the eForce line, wired and packaged as a ready-to-install unit at 48 volts.
At 28.8kWh total capacity, this kit gives you roughly 600Ah at 48V nominal — usable runtime depends on your load and your inverter's efficiency, but this is the number to plug into your load calculations before sizing a system.
Battery Characteristics
Chemistry: Lithium Iron Phosphate (LiFePO4). LFP chemistry is chosen for its thermal stability and long cycle life compared to older lithium formats, and it does not contain cobalt.
Cell Configuration: The eForce battery module uses a 15-cell configuration (this differs from Fortress Power's eVault MAX, eFlex MAX, and eBoost lines, which use 16 cells — do not assume parts or BMS behavior are interchangeable across those product lines).
Design: Modular and stackable, with an all-weather outdoor-rated enclosure and built-in temperature-controlled heating for cold-climate operation. Battery modules connect via two Wireless Quick Plugs per unit, which Fortress Power designed to simplify adding capacity without complex rewiring.
Wiring & Configuration Limits
The eForce system is built for expansion: up to 16 of the 9.6kWh battery modules can be combined into a single system reaching 153kWh total capacity. This kit (28.8kWh) represents a mid-size configuration within that range.
The system connects through the eWay wireway, which houses busbars, conduit ports, and an emergency disconnect switch — this is the backbone for adding modules rather than field-wiring raw battery terminals together. The Fortress Power Envy True 12kW inverter is designed to mount directly onto the eWay for a combined storage-and-inverter tower.
What this is NOT: This is not a starter/cranking battery, and it is not designed for series/parallel field-wiring outside the eWay/Wireless Quick Plug architecture Fortress Power specifies. [NEEDS VERIFICATION: exact max continuous discharge/charge amperage and peak discharge specification for the eForce BMS were not present in manufacturer source data provided.]
Pro-Installer Tip
Homeowners sometimes assume any lithium charger or any inverter will "talk" correctly to a modular battery like this. It won't necessarily. Mixing battery modules of different ages or firmware revisions in the same stack can create charge imbalance between modules, since each module's internal BMS manages its own cells independently. Over time, an imbalanced stack forces the weakest module to hit its charge or discharge limits first, dragging down usable capacity for the whole bank and increasing the chance of a BMS lockout event. Use a system monitor that reports state-of-charge per module (not just pack-level voltage) so you catch drift early. As a professional standard, plan your depth-of-discharge assumptions around what Fortress Power's cycle rating implies for this chemistry — LiFePO4 systems are typically cycled deeper than lead-acid, but always confirm the eForce's specific recommended DoD in the manufacturer resources before finalizing system sizing.
Key Benefits
- 8,000+ cycle life rating, per Fortress Power, without cell degradation under fast charging
- Modular design — start at 9.6kWh and scale to 153kWh across up to 16 modules
- Outdoor-rated, all-weather enclosure with built-in temperature-controlled heating
- Real-time LED status indicators on each module
- Virtual Power Plant (VPP) compatible in eligible service areas, allowing potential revenue generation from the system
- Wireless Quick Plug connections between modules to simplify installation
Technical Table
| Spec | Value |
|---|---|
| Voltage | 48V |
| Capacity | 28.8kWh (this kit) / 9.6kWh per module |
| Chemistry | LiFePO4 (Lithium Iron Phosphate) |
| Cell Configuration | 15-cell |
| Cycle Life | 8,000+ cycles |
| Max System Size | Up to 16 modules / 153kWh |
| Enclosure | Outdoor-rated, all-weather, with temperature-controlled heating |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
The eForce battery module is designed to pair with the Fortress Power eWay wireway and the Envy True 12kW inverter, which mounts directly onto the eWay to form a combined tower. Modules connect to each other via Wireless Quick Plug connections.
NOT compatible with: This battery is not a drop-in replacement for eVault MAX, eFlex MAX, or eBoost batteries — those product lines use a 16-cell configuration, while the eForce uses 15 cells. Do not mix eForce modules with those other Fortress Power lines in the same stack. This is not a starter/cranking battery. Standard lead-acid chargers are not appropriate for this LiFePO4 system — charging must go through the compatible inverter/BMS architecture Fortress Power specifies for the eForce line. [NEEDS VERIFICATION: whether this kit ships with the eWay wireway included, or whether eWay is sold separately, is not stated in the manufacturer text provided.]
FAQ
Q: Is this a starter or cranking battery?
A: No. This is a stationary home/off-grid energy storage battery. It is not designed or rated for engine starting applications.
Q: Can I mix eForce modules with Fortress Power's eVault MAX, eFlex MAX, or eBoost batteries?
A: No. The eForce uses a 15-cell configuration, while those other lines use 16 cells. Do not combine them in the same battery bank.
Q: How much can this system scale?
A: Fortress Power states the eForce platform can scale up to 16 battery modules for a total system size of 153kWh. This listed kit is 28.8kWh, equivalent to three modules.
Q: Does this battery work in cold climates?
A: Fortress Power specifies an all-weather outdoor-rated enclosure with built-in temperature-controlled heating for the eForce line.
Q: Is this system eligible for Virtual Power Plant (VPP) programs?
A: Fortress Power states the eForce supports VPP participation for homeowners in eligible service areas, which may allow revenue generation from the system. Eligibility depends on your local utility/program — confirm with your installer.
Warranty & Support
Warranty terms and full manufacturer documentation for the eForce line are available in the "Resources (System Manuals and Warranty)" Tab above on this page. If you're unsure whether this kit fits your planned system size, ask us before you order — we always reply back.
