Fortress Power Solo 6.5kW Off-Grid Solar Bundle with 10.8kWh eFlex MAX Batteries

$5,307.00 $4,663.00 Save 12%
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Get started with off-grid energy at a cost-effective level. This bundle includes the reliable Solo 6.5kW off-grid inverter paired with two eFlex MAX 5.4kWh lithium batteries (total 10.8kWh) to form a compact, efficient solar + storage setup.

The Solo inverter features a built-in 140A MPPT solar charge controller, supports generator input, and intelligently switches between power sources to keep your system stable. Meanwhile, the eFlex MAX batteries deliver over 8,000 life cycles, >98% efficiency, and integrated busbars for easy wiring. Everything is engineered to be DIY-friendly, stable, and performance-driven for off-grid homes, cabins, or backup systems.


Applications

  • Remote home backup power 
  • Off-grid homes and cabins 
  • DIY solar setups

Introduction to the Fortress Power Solo 6.5K Inverter

Introduction to the Fortress Power eFlex Max 5.4kWh Battery

Why Choose This Bundle?

🔋 Reliable Energy, Day and Night

The eFlex MAX lithium battery provides 5.4kWh of usable capacity per unit, expandable up to 10.8kWh in this kit. Paired with the SOLO 6.5kW inverter, you’ll have consistent power delivery day and night — even during grid outages.

⚡ All-in-One Power Management

The SOLO inverter intelligently manages solar, battery, and generator inputs to maximize efficiency and uptime. It automatically switches between sources for an uninterrupted power experience.

💡 High Efficiency & Long Lifespan

Engineered with advanced LFP cells and a pure sine wave inverter, this system offers over 98% conversion efficiency and 8,000+ cycles at 80% DoD — ensuring clean, reliable power for over 10 years.

🛠️ Simplified DIY Installation

Both components are designed for plug-and-play setup. The SOLO’s integrated AC/DC breakers and smart monitoring interface make wiring safe and simple, while the eFlex MAX wall-mount design saves space and installation time.

🌍 Off-Grid Independence at a Lower Total Cost

Save more with a system that includes everything you need for off-grid power — inverter, batteries, communication cables, busbars and breakers — all pre-matched and ready to install.

💵 Free Shipping & Long-Term Value

Every bundle includes free shipping, a 10-year warranty, and access to expert support — ensuring a worry-free, cost-effective investment in your energy future.

Solo 6.5kW & eFlex Max Installation Videos

Step-by-step setup guide. Coming Soon~

Solo 6.5kW & eFlex Max Influencer Videos

Hear what influencers think. Coming Soon~

Solo 6.5kW & eFlex Max 5.4kWh Technical Specs & Downloads

Get the details you need—spec sheets, manuals, and performance data all in one place. We link directly to the manufacturer's site, so you know you always have the most up-to-date information.

GENERAL DATA
Weight 47.84 lbs (21.7 kg)
Operating Temperature 14 ºF - 131 ºF (-10 ºC - 55 ºC), >45 ºC derating
Protection Level IP20 (for indoor use only)
Noise <60db
Dimensions (H x W x D) 27 x 16.1 x 5.5 in (686 x 410 x 140 mm)
Cooling Mode Fan
INVERTER OUTPUT
Rated Output Power 6,500W
Maximum Peak Power 13,000 VA
Rated Output Voltage 120/240 VAC (Single/Split-Phase)*
Rated Frrequency 50/60Hz*
Output Wave Pure Sine Wave
Switching Time 10 ms (typical value)
Parallel Number 6
BATTERY PARAMETERS
Compatible Battery Type Lithium-ion battery / lead-acid battery / user- defined battery*
Rated Battery Voltage 48 Vdc
Voltage Range 40 Vdc-60 Vdc*
Maximum Grid/Generator Charge Power TBD
Maximum Battery Charge Power (with PV) 140 A DC*
PV INPUT
MPPT Channel Number 2
Maximum Input Power 5,000W+5,000W
Maximum Input Short Circuit Current 18 / 18 A
Maximum Open Circuit Voltage 550 Vdc / 550Vdc
MPPT Operating Voltage Range 150 Vdc-450 Vdc
GRID / GENERATOR INPUT
Input Phase Voltage Range 65 VAC - 140 VAC
Grid Frequency Range 50/60 Hz
Bypass Overload Current 40A
COMMUNICATION
Built-in Interface RS485 / CAN / USB / dry contact*
External Module (Optional) Wi-Fi / GPRS*
EFFICIENCY
MPPT Tracking Efficiency 99.9%
Maximum Efficiency of Battery Inverter 93%
STANDARDS & CERTIFICATIONS
Safety Standards IEC62109-1, IEC62109-2, and UL1741
EMC EN61000-6-1, EN61000-6-3, and FCC 15 class B
RoHS Yes
General
Name eFlex MAX 5.4
Total Energy(kWh) 5.4
Max. Charge Current (Continuous) [A] 100
Max. Discharge Current (Continuous) [A] 100
Nominal Capacity [Ah] 105
Voltage Range [V] 48-55
Charging Temperature [F] 32 ~ 114
Discharging Temperature [F] -4 ~ 131
Storage Temperature [F] 20 ~ 95
Dimension [L x W x H, inch] 17.5 x 24.2 x 7.2
Weight [lbs] 108
Life Cycles 8000 @ 80% DoD
Round Trip Efficiency >98%

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We don't just sell parts, we sell solutions

Our team is focused on taking the complexity out of energy storage and solar systems. That means carefully selected products, simplified kits, and resources built around helping you do it yourself—or do it right the first time. We combine technical know-how with honest guidance to make sure your power system actually works for your lifestyle or business.