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EcoFlow STREAM Pro vs Fronius Reserva 15.8

Usable capacity: EcoFlow STREAM Pro –, Fronius Reserva 15.8 15.79 kWh. The Fronius Reserva 15.8 is better on 3 of 8 comparable points.

Who wins where

  • EcoFlow STREAM Pro
  • Fronius Reserva 15.8
PerformanceElectricalDimensions & weightWarranty & lifespan
Performance: EcoFlow STREAM Pro 6, Fronius Reserva 15.8 86; Electrical: EcoFlow STREAM Pro 50, Fronius Reserva 15.8 50; Dimensions & weight: EcoFlow STREAM Pro 86, Fronius Reserva 15.8 56; Warranty & lifespan: EcoFlow STREAM Pro 47, Fronius Reserva 15.8 47

Biggest differences

FactSTREAM ProReserva 15.8
Charge power (continuous)1.05 kW16.38 kW
Discharge power (continuous)1.2 kW16.38 kW
Nominal capacity1.92 kWh16.71 kWh
Weight22.8 kg187 kg
All specifications ↓

Score per area = position (0–100) relative to all 130 models in this category; higher is better.

Technical specifications EcoFlowSTREAM Pro FroniusReserva 15.8
General
Cell chemistry LFP 1 LFP 2
Smart charging on dynamic prices Yes 1 –
Wi-Fi / app Yes 1 –
Performance
Usable capacity – 15.79 kWh 2
Nominal capacity 1.92 kWh 1 16.71 kWh ✓ 3
Expandable up to 11.52 kWh 1 –
Charge power (continuous) 1.05 kW 1 16.38 kW ✓ 2
Discharge power (continuous) 1.2 kW 1 16.38 kW ✓ 2
Efficiency
Round-trip efficiency – 95 % 2
Electrical
Coupling – DC-coupled 2
Backup power Yes 1 Yes 2
Off-grid capable Yes 1 –
Dimensions & weight
IP rating IP65 1 IP65 2
Min. operating temperature -20 °C 1 -20 °C 2
Width 284 mm 1 772 mm 2
Height 458 mm 1 1,640 mm 2
Depth 255 mm 1 176 mm 2
Weight 22.8 kg ✓ 1 187 kg 2
Warranty & lifespan
Warranted cycles 6,000 1 6,000 2
Warranty 10 years 1 10 years 2

Sources

  1. EcoFlow STREAM Ultra/Pro Specifications, 1.0 — EcoFlow UK · accessed 29 Sept 2026
  2. The Fronius storage solution, V09 Sep 2026 — Fronius International GmbH · accessed 29 Sept 2026
  3. CEC approved solar batteries (Australia) — Clean Energy Regulator (Australian Government), CC BY 4.0 · accessed 29 Sept 2026