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)No
UL 1741 SA (Rule 21)No
CSIP (IEEE 2030.5)No
JA12 declaration (Title 24)Yes
JA12 control strategiesBasic, TOU, Advanced DR
Last CEC updateDec 2, 2024
Monitor Key Data schedulingNo
Compare with similar batteries
CEC Energy Storage System List
Battery
Energy
Continuous power
Chemistry
Warranty
SoCal permits
Sol-Ark L3 HVR
36.9–55.3 kWh
30–60 kW
Lithium Iron Phosphate
10 years
7
Sol-Ark L3 HV-xxKWH-xxK
36.9–55.3 kWh
30–60 kW
Lithium Iron Phosphate
10 years
—
Same segment, similar capacity; each row from the same sources.
Questions & answers
How much energy does the Shanghai PYTES Energy Forest MxxK store?
61.4 kWh nameplate, per the California Energy Commission list.
Is the Forest MxxK UL 9540 certified?
Yes — the CEC list shows UL 9540 certification (certified by sgs).
Sources
California Energy Commission — Energy Storage System List, data as of Oct 7, 2026. Manufacturer-reported values confirmed by CEC against certificates.
NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Riverside, Santa Clarita, Chula Vista, Huntington Beach.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).
Get your free estimate
Three fields, and Cali Energy calls back within 30 minutes during business hours.
Thanks!
We got your request and will call back within 30 minutes during business hours.