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Enphase IQ Battery 5P with FlexPhase vs Fronius Reserva 6.3

Usable capacity: Enphase IQ Battery 5P with FlexPhase 5 kWh, Fronius Reserva 6.3 6.31 kWh. Both models win equally often (2 of 7 points).

Who wins where

  • Enphase IQ Battery 5P with FlexPhase
  • Fronius Reserva 6.3
PerformanceEfficiencyElectricalDimensions & weightWarranty & lifespan
Performance: Enphase IQ Battery 5P with FlexPhase 19, Fronius Reserva 6.3 28; Efficiency: Enphase IQ Battery 5P with FlexPhase 2, Fronius Reserva 6.3 44; Electrical: Enphase IQ Battery 5P with FlexPhase 50, Fronius Reserva 6.3 50; Dimensions & weight: Enphase IQ Battery 5P with FlexPhase 73, Fronius Reserva 6.3 72; Warranty & lifespan: Enphase IQ Battery 5P with FlexPhase 72, Fronius Reserva 6.3 47

Biggest differences

FactIQ Battery 5P with FlexPhaseReserva 6.3
Warranty15 years10 years
Usable capacity5 kWh6.31 kWh
Round-trip efficiency90 %95 %
Weight83 kg86.5 kg
All specifications ↓

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

Technical specifications EnphaseIQ Battery 5P with FlexPhase FroniusReserva 6.3
General
Cell chemistry LFP 1 LFP 2
Wi-Fi / app Yes 1 –
Performance
Usable capacity 5 kWh 1 6.31 kWh ✓ 2
Nominal capacity – 6.68 kWh 3
Charge power (continuous) – 6.55 kW 2
Discharge power (continuous) – 6.55 kW 2
Efficiency
Round-trip efficiency 90 % 1 95 % ✓ 2
Electrical
Coupling AC-coupled 1 DC-coupled 2
Phases 3 1 –
Backup power Yes 1 Yes 2
Dimensions & weight
IP rating IP55 1 IP65 2
Min. operating temperature -20 °C 1 -20 °C 2
Width 550 mm 1 772 mm 2
Height 980 mm 1 890 mm 2
Depth 188 mm 1 176 mm 2
Weight 83 kg ✓ 1 86.5 kg 2
Warranty & lifespan
Warranted cycles 6,000 1 6,000 2
Warranty 15 years ✓ 1 10 years 2

Sources

  1. IQ Battery 5P with FlexPhase – EMEA data sheet, DSH-00477-9.0-EN-2026-08-21 — Enphase Energy, Inc. · accessed 27 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