Fox ESS announces Power Q: New residential storage system line with 89.6% round-trip efficiency

Chinese storage system provider Fox ESS has launched a new residential storage system series at the Solar Solutions Amsterdam 2026 trade show.

“The innovative cable-free system further revolutionizes installation with unmatched simplicity and convenience,” the manufacturer said in a statement. “While not yet commercially available, it is already generating significant excitement and high expectations.”

The series comes equipped with a built-in gateway featuring a 63 A breaker, making it ideal for whole-house load backup. Its maximum 1 C charge and discharge rate allows rapid energy management, making the system well-suited for virtual power plant (VPP) applications and enabling users to fully leverage multi-scenario benefits, according to the company.

The system supports 6CT/3CT meters with self-adaptive phase sequencing, VPP integration, 5-second power scheduling, and one-click APP upgrades, providing effortless optimization and real-time responsiveness, Fox ESS said. Round-trip efficiency reportedly reaches up to 89.6%.

The Power Q line comprises bith single-phase system and three-phase systems, both built with LFP lithium-ion batteries.

The single-phase product can operate with a maximum PV array power of 20 kW and a maximum input voltage of 600 V. Its MPPT voltage range spans 80–550 V, with full-load operation supported from 80–500 V. Multi-tracker configurations, with up to four MPPTs supporting multiple strings, allow complex array setups to be optimized for maximum energy harvest. The system starts at just 80 V, with a nominal operating voltage of 360 V, ensuring reliable performance across varied solar conditions, the company said.

The inverter supports voltages from 80–500 V, with deep-cycle operation allowing up to 90% depth of discharge. Maximum battery charge and discharge power can reach 12 kW. Rated AC output power ranges from 3.7 kW to 12 kW depending on the model, with grid voltage options of 220, 230, or 240 V and a rated frequency of 50/60 Hz.

Inverter conversion efficiency reaches 97.62%, while European efficiency is 97.20%, and MPPT efficiency tops 99.9%. Battery charge and discharge cycles purportely achieve up to 96.4%. imensions range around 570 mm × 420 mm × 380 mm for most models, with net weights between 35 kg and 63 kg.

As for the three-phase system, it supports maximum array power from 11 kW to 30 kW depending on the model, with MPPT voltage ranges from 120 V up to 950 V. Each inverter includes three MPPT trackers, supporting multiple strings per tracker.

The system operates across 80–500 V with scalable capacity. Peak battery charge and discharge powers reach up to 15 kW, according to the manufacturer. AC output is tailored for three-phase systems, ranging from 5 kW to 15 kW nominal power, with rated voltages of 400/230 V or 380/220 V.

The inverter reportedly achieves up to 97.9% conversion efficiency, with MPPT efficiency at 99.9%.

Physical dimensions vary by model, ranging approximately from 570 mm × 420 mm × 380 mm for smaller units to 570 mm × 915 mm × 380 mm for larger multi-module configurations. Weight also scales with capacity, from around 40 kg for entry-level models to over 60 kg for high-capacity units.

“All systems ensures up to 89.6% round-trip efficiency, maximizing revenue and shortening payback period,” the manufacturer stated.