Top Fortress Power Batteries Comparison Guide

EcoVault offers four top-tier lithium batteries from Fortress Power, each designed for different needs. Below is a clear comparison of the LFP-10 Max, eFlex MAX 5.4kWh, eVault Max 18.5kWh, and eForce 9.6kWh, to help you choose the best fit.

Key Specifications Compared

Picture
Feature	LFP-10 Max 10.24kWh	eFlex MAX 5.4kWh	eVault Max 18.5kWh	eForce 9.6kWh
Nominal Voltage	51.2V	51.2V	51.2V	48V
Capacity	10.24kWh	5.4kWh	18.5kWh	9.6kWh
Max Parallel Units/ Scalability	2 (20.48kWh)	16 (86.4kWh)	20 (370kWh)	16 (153kWh)
Max Charge/Discharge	120A / 6kW	100A / 5kW	180A / 12.8kW	250A / 12kW
Cycle Life (80% DoD)	6,000 cycles	8,000 cycles	8,000 cycles	8,000 cycles
Weight	210 lbs (95 kg)	108 lbs (49 kg)	520 lbs (236 kg)	269 lbs (122 kg)
IP Rating	IP30	IP65	IP55	IP65
Mounting	Floor/Standing	Wall/Rack/Floor	Floor/Standing	Wall/Floor/Ground
Highlights	Budget-friendly, Cheaper per kWh	Compact design, Aluminium enclosure	High Capacity (18.5 kWh), Serviceable top cover	eWay (integrated wireway and busbar), Quick plug installation & Stackable up to 28.8kWh vertically
Best For	Small/Medium systems	Rugged outdoor use	Large homes/business	Whole-home backup
Battery Pack Price	$1,999* $195/kWh	$1,399* $259/kWh	$5,599* $302/kWh	$4,255* $443/kWh

Note: * as per published price on ecovault.com in Apr, 2025.

Which Battery Should You Choose?

1. LFP-10 Max 10.24kWh

✅ Best for:

Small to medium energy needs (up to 162kWh).
Compact design & stand-mount.
Budget-friendly entry into solar storage.

❌ Limitations:

Lower max parallel capacity (20.48kWh).

2. eFlex MAX 5.4kWh

✅ Best for:

Extreme weather (IP65 + better thermal design).
Lightweight/modular installations.
Budget conscious homeowners.

❌ Limitations:

Lower max discharge (5kW) vs. eForce/eVault.

3. eVault Max 18.5kWh

✅ Best for:

Large homes/businesses (single-unit high capacity).
Industrial/commercial (370kWh max parallel).
High discharge needs (12.8kW surge).

❌ Limitations:

Heaviest (520 lbs) and IP55 (less weatherproof).

4. eForce 9.6kWh

✅ Best for:

Whole-home backup (stackable up to 153kWh).
High-power demands (12kW continuous discharge).
Outdoor/harsh environments (IP65 rated).
Simple installation (quick plug)

❌ Limitations:

Heavier than eFlex MAX.

Final Decision Guide

Need	Best Option
Whole-home backup (scalable)	eForce 9.6kWh
Budget-friendly system	LFP-10 Max
Large capacity (single unit)	eVault Max 18.5kWh
Rugged outdoor/lightweight	eFlex MAX 5.4kWh