Skip to content
Contact Us Price Match Guarantee FAQs Why Buy From Us About Us Customer Reviews Installer Program Build Your System
Fortress Power Solo 6.5K Inverter

Fortress Power Solo 6.5K Inverter
Save 23% Save 23%
$2,013.70
$2,013.70 - $2,013.70
$2,013.70
$1,549.00
$1,549.00 - $1,549.00
$1,549.00
✓ Authorized Fortress Power Dealer
✓ Lowest Price Match Guarantee
✓ FAST & FREE Shipping: In Stock Ready To Ship
✓ Questions? Talk to a Fortress Power Expert: 1-303-876-7654

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

6,500W · Pure Sine · Off-Grid Ready

Fortress Power Solo 6.5K Inverter

The Solo 6.5K delivers 6,500W of continuous pure sine wave output with dual MPPT solar input up to 10,000W, built for off-grid and battery-backup systems at a nominal 48V.

It parallels with up to 5 more units for up to 39kW combined, and switches from grid to battery in about 10ms.

Fortress Power Solo 6.5K Inverter
Lowest Price Guarantee
Authorized Fortress Power Dealer
Free Shipping
0% APR Financing
Expert Support: (303) 876-7654
Genuine Fortress Power

Why the Solo 6.5K

6,500W Pure Sine Wave Output

6,500W continuous with a 13,000VA peak, clean enough for sensitive electronics and motors that a modified-sine inverter can damage or run inefficiently.

Dual MPPT, Up to 10,000W Solar Input

Two MPPT channels accept up to 5,000W each for 10,000W of solar PV input total, across a 150–450Vdc operating range.

Parallel Up to 6 Units, 39kW Total

Stack up to 6 units for up to 39kW of combined output as a system grows.

Works With Lithium, Lead-Acid, or User-Defined Batteries

Flexible battery-type configuration at a nominal 48V, with up to 140A max charge current.

10ms Transfer Switch Time

Fast enough that most connected electronics won't reset during a grid-to-battery transfer.

SOLARMAN App Monitoring

Monitor and manage the system remotely through the SOLARMAN mobile app.

What's Included

What's included with the Fortress Power Solo 6.5K

What You Get

  • 1 × Fortress Power Solo 6.5K Inverter
  • Documentation

Battery bank and solar array sold separately.

Full Specifications

Model Fortress Power Solo 6.5K (FP-SOLO-6.5)
Continuous AC Output 6,500W
Peak Output 13,000VA
Output Waveform Pure sine wave
Output Voltage 120/240VAC single/split-phase, 50/60Hz
Switching Time 10ms (typical)
Solar (PV) Input 2 MPPT channels, 5,000W + 5,000W; operating range 150–450Vdc; max Voc 550Vdc; short-circuit current 18A per channel
Grid/Generator Input Voltage 65VAC–140VAC
Bypass Overload 40A
Max Charge Power (Grid) 9,600W
Max Charge Power (Generator) 4,000W
Parallel Capability Up to 6 units, up to 39kW total
Nominal Battery Voltage 48Vdc (range 40–60Vdc)
Compatible Battery Types Lithium-ion, lead-acid, or user-defined
Max Charge Current 140A DC
Efficiency MPPT 99.9%; max battery-to-inverter 93%
Dimensions Fortress Power lists this two ways: 27"W × 16.1"D × 5.5"H on the product page, 27"W × 16.1"D × 6.1"H on the datasheet PDF — both published, not reconciled by Fortress Power
Weight Also listed two ways: 47.84 lb on the product page, 50.71 lb on the datasheet PDF
Certifications IEC62109-1, IEC62109-2, UL1741, EN61000-6-1, EN61000-6-3, FCC15 Class B, RoHS
Warranty Not published by Fortress Power for this model
Monitoring SOLARMAN mobile app

Authorized Fortress Power Dealer

We sell genuine Fortress Power products backed by Fortress Power'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 system or checking inverter compatibility? Call (303) 876-7654 and talk to a person.

Fortress Power Solo 6.5K Inverter: Frequently Asked Questions

What's the actual weight and dimensions — the two published figures don't match.
Fortress Power's own product page and datasheet PDF give slightly different numbers (weight: 47.84 lb vs. 50.71 lb; dimensions differ by about 0.6" in depth). Both are Fortress Power's own figures; we're reporting both rather than guessing which is current. Call (303) 876-7654 if exact shipping weight matters for your installation.
What's the warranty on this inverter?
Fortress Power doesn't publish a warranty length for the Solo 6.5K on either its product page or datasheet. Call (303) 876-7654 and we'll get written confirmation before you order.
How much solar can I connect?
Up to 10,000W across two independent MPPT channels (5,000W each), each accepting 150–450Vdc.
Can I run more than one of these together?
Yes, up to 6 units can be paralleled for up to 39kW combined output. Call (303) 876-7654 if you're planning a multi-unit install and we can help you size it.
What batteries work with this inverter?
It's flexible on battery type — lithium-ion, lead-acid, or user-defined — at a nominal 48V. Confirm your specific battery's compatibility before ordering.
Can I install this myself, or do I need an electrician?
Fortress Power's equipment is designed for professional installation. We strongly recommend a licensed electrician or solar installer for any battery, inverter, or enclosure installation — call (303) 876-7654 if you need a referral in your area.
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 Fortress Power dealer, call us at (303) 876-7654 before you order and we'll take care of it.
Renewable Outdoors LLC BBB Business Review