Quietly Powerful: Hoymiles HoyUltra 2 C&I ESS Achieves Breakthrough ≤60 dB(A) in Certified Noise Testing

HANGZHOU, China, Feb. 12, 2026 /PRNewswire/ -- As energy storage systems (ESS) are increasingly deployed in commercial centers and residential neighborhoods, noise levels have become a critical factor for project approval. Hoymiles' HoyUltra 2, the liquid-cooling C&I battery system, has achieved ≤60 dB noise level certification in a recent noise evaluation test conducted according to the international ISO 3744:2010 standard by the Zhejiang Electric Safety and Quality Inspection Center. While the industry average is 65–75 dB, the breakthrough ≤60 dB certification of HoyUltra 2 sets it as one of the quietest in the industry.

The gold standard of silence

Unlike tests conducted in noisy industrial environments, the HoyUltra 2 was tested in a professional semi-anechoic chamber with a background noise level of just 24 dB—quieter than a bedroom at night.

The evaluation covered the system's entire operational cycle, including full-power charging and discharging. The results confirmed that even under maximum load, the noise remains consistently low and stable, free from mechanical hums.

Seamless urban integration

At the overall A-weighted sound pressure level of 47.4 dB(A), the operating volume of the HoyUltra 2 is comparable to a quiet library. This is a significant leap from traditional ESS units, which typically operate between 65–75 dB.

This breakthrough allows the HoyUltra 2 to blend seamlessly into noise-sensitive environments, such as:

• Commercial business districts
• Industrial parks
• Residential communities

Innovative liquid-cooling engineering behind the low decibels

The silence of the HoyUltra 2 is a result of "System-Level Quiet Engineering", which integrates acoustics into product design from the very beginning:

• Multi-dimensional noise suppression: Hoymiles has optimized the refrigeration system and air duct architecture to enhance heat exchange efficiency while eliminating internal turbulence.
• Balance of efficiency and quietness: The coordinated control for fans and compressors prevents unnecessary and excessive high-speed operation.
• Fully liquid-cooling architecture: Compared to traditional systems, the fully liquid-cooling architecture achieves significantly fewer fans and lower RPMs, controlling noise at the source.
• Acoustic stability and control: The seamless alignment between the product's physical form and its acoustic profile proves that noise control was a core design requirement from the initial layout phase.

By removing the "noise barrier," Hoymiles is opening up new possibilities for ESS deployment where space is tight and neighbors are close.

Learn more information at https://www.hoymiles.com/products/hoyultra2-all-in-one-battery-system.html