Flexible cable for BESS: Top Cable launches Powerflex Ultra for Battery Energy Storage Systems

Conventional low-voltage cables are designed for fixed installations with moderate mechanical requirements. A cable for BESS infrastructure combines high flexibility — to ease routing in high cable-density containers —, extended thermal resistance at elevated service temperatures, and a service life suited to the operating horizon of storage systems, which typically exceeds 20 years. The POWERFLEX® Ultra BESS meets these three requirements simultaneously.

Under IEC 60228, class 6 defines flexible conductors made up of a greater number of finer-gauge wires than class 5, reducing the overall stiffness of the assembly. A class 6 conductor offers greater flexibility and a smaller minimum bending radius than a class 5 conductor, making it especially suitable for installations with confined spaces or frequent connections between equipment, such as those found in battery containers and PCS units.

Yes. The 1.8/3 kV AC version is directly suitable for use at 1,500 V DC, in accordance with the AC/DC voltage equivalence criteria established in applicable standards. This makes it compatible with new-generation string inverters and power conversion centers operating at this voltage, common in utility-scale storage and photovoltaic projects.

Standard PVC-based cables are designed to operate continuously up to 70°C, with design lives generally below 30 years at that temperature. The POWERFLEX® Ultra BESS maintains its mechanical and electrical properties for 30 years at a 90°C service temperature. In practice, if the cable operates below its rated maximum temperature, the actual service life can significantly exceed 30 years. This factor is decisive in projects with financing horizons of 25 to 35 years.

The AD8 rating, defined in IEC 60529, certifies that the cable can operate under permanent water immersion conditions. This rating is required in installations located in areas with high water tables, coastal sites, or environments with periodic flood risk. In BESS projects installed in regions with these conditions, the AD8 rating eliminates the need for additional waterproofing protection.

Yes. The POWERFLEX® Ultra BESS meets the UV resistance requirements set out in EN 50618, the European reference standard for cables used in photovoltaic and energy storage systems. This compliance allows outdoor installation without additional protection against solar radiation, both in generation applications and in the interconnection of storage equipment.

The minimum bending radius depends on conductor cross-section and installation configuration. As a cable with a class 6 conductor and a proprietary flexible compound jacket, its minimum radius is smaller than equivalent cables with a class 5 conductor and standard PVC jacket. For exact values by cross-section, consult the product datasheet or contact Top Cable’s technical team.

The POWERFLEX® Ultra BESS can be installed direct-buried, in ducts or conduits, on cable trays, and outdoors. The AD8 rating also allows use in permanent immersion environments. Thanks to EN 50618 compliance, it requires no additional UV protection in outdoor installations. These characteristics broaden the range of sites where it can be used without additional engineering constraints.

The certifications have been issued by AENOR, Bureau Veritas and KEMA-KEUR, all independent third-party certification bodies with international recognition. The product also carries CE and UKCA marking for commercialization in the European and British markets. These certifications are accepted by most financing banks, infrastructure funds and EPC contractors as part of project technical documentation.

European manufacturing ensures compliance with EU quality and traceability standards, facilitates access to technical and conformity documentation, and reduces supply-chain risks. In projects with public funding or subject to regulatory frameworks requiring European origin of equipment, the cable’s origin can be an explicit eligibility requirement.

Cable flexibility reduces the time required for routing in high-density areas, minimizes the physical effort needed to connect equipment in confined spaces, and lowers the risk of mechanical damage during installation. In large-scale BESS projects, reduced installation time can represent significant savings in labor cost, one of the most significant components of installation CAPEX.

Yes. The POWERFLEX® Ultra BESS complies with EN 50618, the reference standard for cables in photovoltaic systems, and is available in voltage versions compatible with the most common electrical architectures in solar plants. Its use in integrated PV+BESS projects is particularly suitable, as it allows cable specification to be unified across both subsystems, simplifying materials management and project technical documentation.

The POWERFLEX® Ultra BESS withstands short-circuit temperatures of up to 250°C. In Battery Energy Storage System installations, short-circuit currents can be high due to the low internal impedance of lithium batteries under fault conditions. A cable with a higher allowable short-circuit temperature provides a greater safety margin against these events and allows the selection of optimized conductor cross-sections without the need to oversize on thermal grounds.

The POWERFLEX® Ultra BESS is manufactured in a range of cross-sections suited to utility-scale energy storage applications. For exact availability of cross-sections, voltages and conductor configurations, consult Top Cable’s updated technical catalog or contact the sales team directly.

For the POWERFLEX® Ultra BESS, Top Cable provides a complete technical datasheet, test reports issued by accredited laboratories, certificates of conformity from AENOR, Bureau Veritas and KEMA-KEUR, and CE declarations of performance.