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102 kWh

Commercial energy storage systemFortress Power

Fortress Power MINI-50-135-xxx-480

102 kWh · 50 kW · Lithium Ion · direct PV input

UL 9540UL 1741 SBCEC listed · Feb 21, 2025

Nameplate energy102 kWh
Continuous power50 kW
ChemistryLithium Ion

Overview

CEC Energy Storage System List

MINI-50-135-xxx-480: 102 kWh nameplate energy; 50 kW continuous; lithium ion; accepts solar panels directly (DC-coupled).

Capacity & power

CEC Energy Storage System List

Nameplate energy (CEC)102 kWh
Rated power (CEC)50 kW
Max continuous discharge (CEC)50 kW
Full-power discharge timeabout 2 h at full power
ChemistryLithium Ion
Grid connection480 V

Safety listings

CEC Energy Storage System List

UL 9540 (energy storage system)Certified by Intertek
Certificate date & editionMar 14, 2024 · Ed. 2 : 2020

UL 9540 certifies the whole storage system; UL 9540A is the fire-propagation test that fire codes ask for indoors and near walls.

California grid & code compliance

CEC Energy Storage System List

UL 1741 SB (IEEE 1547-2018)Yes
UL 1741 SA (Rule 21)No
CSIP (IEEE 2030.5)Yes (with conditions)
JA12 declaration (Title 24)No
Monitor Key Data schedulingYes

Questions & answers

How much energy does the Fortress Power MINI-50-135-xxx-480 store?

102 kWh nameplate, per the California Energy Commission list.

Is the MINI-50-135-xxx-480 UL 9540 certified?

Yes — the CEC list shows UL 9540 certification (certified by intertek).

Sources

California Energy Commission — Energy Storage System List, data as of Oct 7, 2026. Manufacturer-reported values confirmed by CEC against certificates.