Description

SolaX TSYS-HS51 20.4 kWh (T-HS20.4) is the TBMS-S51-8 control unit with four 5.1 kWh TB-HS51 modules; usable energy is 18.3 kWh. This is the configuration for a home whose largest consumer is a heat pump or electric heating: 13.7 kWh is often not enough for one evening and night of heating, and the fourth module adds 5.1 kWh and 3 kW of power. It suits an 8–12 kW PV plant that fills the storage in half a day in summer.

Why the fourth module

Four modules operate in the 170–232 V range and deliver 12.3 kW rated (14.3 kW maximum) power. Compared with the 15.3 kWh variant, the difference is 5.1 kWh, 47 kg and 168 mm of height. The compensation of the planned APVA call is calculated only up to 15 kWh, so you choose the extra module for reserve: in winter the storage is charged at the night tariff and powers the heating during the day, and on a cloudy day the reserve keeps the house off the grid for longer. If the heat pump is larger or the house is heated by electricity alone, the 25.6 kWh variant gives 15.4 kW of power.

Installation and location

The tower measures 600 × 376 × 957 mm (width × depth × height) and weighs 211.2 kg. The IP66 enclosure suits a garage, an unheated boiler room or an outdoor wall: with heating, charging works from −30 °C, without it from 0 °C, discharging from −20 °C. It stands on the floor against a non-combustible wall with a 100 mm gap to the wall and the inverter; the floor must bear four times the system weight (about 850 kg). Later the tower can be expanded to 8 modules without an additional base.

Inverter compatibility

20.4 kWh is on the official SolaX lists for the single-phase X1-Hybrid G4 (2–8 modules) and the three-phase X3-Hybrid G4 and X3-Ultra 15K–30K (3–13 modules). The maximum 70 A current depends on the inverter model – with the X3-Ultra one battery port supplies 30 A without the combining cable and 60 A with the two-in-one cable. Communication is CAN and RS485; we check your inverter model against its label before ordering.

Safety and warranty

LiFePO4 cells, an aerosol fire suppression module, a 750 V / 125 A DC fuse, cell balancing by the BMS, more than 6,000 cycles. EU warranty is 10 years (SolaX Cloud registration within 90 days of commissioning, compatible SolaX inverter); 70% of capacity or 15.1 MWh of throughput per module is guaranteed. Under the terms of the planned 2026 APVA call, the compensation is calculated per capacity (170 €/kWh, up to 15 kWh).

Technical specifications

Capacity

20.4 kWh (4 × TB-HS51 of 5.1 kWh, 100 Ah)

Usable energy

18.3 kWh (90% DOD)

Power

12.3 kW rated, 14.3 kW maximum

Voltage

204.8 V rated, operating 170–232 V

Current

60 A rated, 70 A maximum

Charge cycles

More than 6,000 (90% DOD)

Operating temperature

Charging from −30 °C with heating (0 °C without), discharging from −20 °C, up to +53 °C

Communication

CAN + RS485

Protection

IP66; aerosol fire suppression; DC fuse 750 V / 125 A

Dimensions (W×D×H)

600 × 376 × 957 mm

Weight

211.2 kg

Mounting

Single floor-standing tower on the supplied base; outdoor or indoor

Compatibility

SolaX X1-Hybrid G4, X3-Hybrid G4, X3-Ultra 15K–30K

Warranty

10 years EU (SolaX Cloud registration within 90 days)