Pylontech Optim US-B1-M1C-A-ex/xx-US-04

Name: Pylontech Optim US-B1-M1C-A-ex/xx-US-04
Brand: Pylontech

66.2–99.3 kWh · 33.1–49.7 kW · Lithium Iron Phosphate · 8 configurations

UL 9540CEC listed · Apr 13, 2026

Overview

CEC Energy Storage System List

Optim US-B1-M1C-A-ex/xx-US-04: 66.2–99.3 kWh nameplate energy; 33.1–49.7 kW continuous; lithium iron phosphate.

CEC Energy Storage System List · 8 listings

Model	Energy	Power	Grid voltage	Round trip	CEC listed
Optim US-B1-M1C-A-ex/66-US-04	66.2 kWh	33.11 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/71-US-04	71 kWh	35.48 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/75-US-04	75.7 kWh	37.84 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/80-US-04	80.4 kWh	40.2 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/85-US-04	85.1 kWh	42.57 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/90-US-04	89.9 kWh	44.94 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/94-US-04	94.6 kWh	47.3 kW	—	—	Apr 13, 2026
Optim US-B1-M1C-A-ex/99-US-04	99.3 kWh	49.66 kW	—	—	Apr 13, 2026

CEC Energy Storage System List

NLR PVWatts v8 · Cali-Graf calculation · CEC Energy Storage System List

Solar array size that refills the battery from empty in one average day, before the home uses any of it (NLR PVWatts v8, 20° south roof).

CEC Energy Storage System List

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

CEC Energy Storage System List

How much energy does the Pylontech Optim US-B1-M1C-A-ex/xx-US-04 store?

66.2–99.3 kWh nameplate, per the California Energy Commission list.

Is the Optim US-B1-M1C-A-ex/xx-US-04 UL 9540 certified?

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

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).