Storage M — 12.3–49.1 kWh modular high-voltage battery

Country: Germany · Model: Storage M

The Storage M modular high-voltage battery holds 12.3–49.1 kWh of usable capacity per tower of 3–12 modules. It goes into homes and small businesses together with Sunny Tripower Hybrid X and Sunny Boy Smart Energy hybrid inverters.

Capacity: 12.3–49.1 kWh per tower
Protection rating: IP66
Temperature: −20…+50 °C
Compatibility: Sunny Tripower Hybrid X, Sunny Boy Smart Energy

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Technical specifications

More from the manufacturer’s documentation
Capacity	12.3–49.1 kWh per tower
Protection rating	IP66
Temperature	−20…+50 °C
Compatibility	Sunny Tripower Hybrid X, Sunny Boy Smart Energy
Warranty	10 years, up to 7.2 MWh/kWh
Configuration	STM-BMS-10 BMS unit + 3–12 STM-BM-4.09-10 modules
Nominal energy capacity	12.99 kWh (Storage M 12.3) to 51.98 kWh (Storage M 49.1)
Usable energy capacity	12.28 to 49.12 kWh
Nominal voltage	172.8 V (3 modules) to 691.2 V (12 modules)
Operating voltage range	151.2–191.7 V (3 modules) to 604–766.8 V (12 modules)
Charge / discharge current	30 A (Sunny Boy Smart Energy); 50 A (Sunny Tripower Hybrid X)
Round-trip efficiency	93.5% at 0.2C
Dimensions (W × H × D)	530 × 605.5 × 405 mm (12.3) to 530 × 1,802.5 × 405 mm (49.1)
Component dimensions	module 530 × 133 × 405 mm; BMS unit 530 × 140 × 405 mm
Weight	120 kg (12.3) to 442.2 kg (49.1); module 36 kg, BMS unit 11.3 kg
Optimum operating temperature	+15 °C to +30 °C
Cooling	natural cooling
Relative humidity	5–100% non-condensing
Storage conditions	−30 °C to +60 °C up to 7 days; −20 °C to +45 °C up to 6 months; 5–95%
Installation altitude	< 3,000 m
DC connection	MC4 Evo 2
Communication interface	RJ45 (CAN), battery interface protocol
Overvoltage category (battery / inverter)	II / II
Max. configuration by inverter	STP Hybrid X 5–15: up to Storage M 36.9; STP Hybrid X 20–30: up to 49.1; Sunny Boy Smart Energy: up to 28.6
Certificates	CE, UN 38.3, IEC 62619, IEC 62477, VDE 2510-50
Customs codes (for reference)
HS code	8507.60
UKTZED code (Ukraine)	8507600000
CN code (EU)	85076000

Specifications are taken from the manufacturer’s technical documentation. Updated 10/31/2026. Customs codes are for reference only; the final code is determined at customs declaration for the specific model.

Description

A tower is built from an STM-BMS-10 control unit and STM-BM-4.09-10 modules of 36 kg each. Modules stack on top of each other with no power or signal cables between them, and capacity grows by adding modules to the tower. Nominal voltage rises with module count, from 172.8 V with three to 691.2 V with twelve, and the battery connects to the inverter through MC4 Evo 2 connectors and a CAN line over RJ45. Round-trip efficiency is 93.5% at 0.2C. The housing is rated IP66 and operates at −20…+50 °C, so the battery can go in a garage or outdoors, with natural cooling and no fans. It runs best at +15 °C to +30 °C. A full 49.1 kWh tower weighs 442.2 kg and stands 1,802.5 mm tall on a 530 × 405 mm footprint, so check the floor load rating. The 10-year warranty covers up to 7.2 MWh of throughput per kWh of capacity.

How to choose

The inverter sets the tower limit. A Sunny Tripower Hybrid X at 5–15 kW takes up to 36.9 kWh, the 20–30 kW models take the full 49.1 kWh, and a Sunny Boy Smart Energy takes up to 28.6 kWh. Charge and discharge current also depend on the inverter, 50 A with Hybrid X and 30 A with Sunny Boy Smart Energy, so the same tower delivers power faster on the three-phase unit. Capacity steps by one module, about 4.09 kWh usable.