Enphase IQ Battery 5P with FlexPhase: UK Price, Specifications, Solar & EV Charging Guide

Enphase IQ Battery 5P with FlexPhase is a home energy storage battery with integrated microinverters and a published usable capacity of 5.0 kWh per unit. It is designed for single-phase or three-phase installations and can be configured for normal grid-connected operation or backup with the appropriate additional equipment.

This UK guide covers the FlexPhase model, order code IQBATTERY-5P-3P-INT. It explains the specifications and practical considerations using Enphase’s documentation rather than hands-on testing.

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Benefits of residential battery storage

Benefits	What it means for your household
Use more solar generation	Store surplus solar energy for later use
Shift electricity purchases	Use appropriate tariff-based charging to reduce purchases during expensive periods
Support backup	Supply correctly configured backup circuits when the required equipment is installed
Contribute to EV charging	Provide stored electricity to a separate, suitably connected home charger

Benefits depend on consumption, tariffs, solar generation, conversion losses and installation design. Battery storage does not guarantee a saving or eliminate grid reliance.

IQ Battery 5P with FlexPhase at a glance

Specification	IQ Battery 5P with FlexPhase
Product	IQ Battery 5P with FlexPhase
Order code	IQBATTERY-5P-3P-INT
Published usable capacity	5.0 kWh per unit
Chemistry	Lithium iron phosphate (LFP)
Architecture	AC-coupled with six integrated IQ8T-BAT Microinverters
Default single-phase continuous output	Up to 3.84 kVA
Default three-phase continuous output	3.84 kVA total; 1.28 kVA per phase
AC round-trip efficiency	90%
Battery-module DC round-trip efficiency	96% at beginning of life
Dimensions (H × W × D)	980 × 550 × 188 mm
Total installed weight	83 kg
Battery enclosure protection	IP55
Cooling	Natural convection
Mounting	Wall-mount included; optional pedestal sold separately
Charging temperature range	−20°C to 50°C; power derating applies
Discharging temperature range	−20°C to 55°C; power derating applies
Backup equipment	IQ System Controller 3 INT required
Battery limited warranty	15 years or 6,000 discharged cycles, whichever occurs first; subject to terms

These figures are from the FlexPhase datasheet. Other IQ Battery variants and configured output ratings may differ. Confirm the exact supplied model and commissioned rating.

What is the Enphase IQ Battery 5P with FlexPhase?

The IQ Battery 5P with FlexPhase is an AC-coupled home battery with six integrated IQ8T-BAT Microinverters and a battery management system. These microinverters convert stored battery energy into AC electricity for the home. They are part of the battery and should not be confused with rooftop solar microinverters.

FlexPhase allows the battery to be configured for single-phase or three-phase use by the installer. The installation also needs the appropriate gateway, communications, metering and protection equipment. Backup requires an IQ System Controller 3 INT.

Pros and cons

Pros	Cons and limitations
AC-coupled architecture can suit suitable existing solar installations	Backup requires additional equipment and installation work
FlexPhase supports single-phase and three-phase configurations	Three-phase output is divided across phases; one unit does not provide 3.84 kVA on each phase
5 kWh increments allow storage capacity to be matched to household needs	The long warranty is subject to cycle, connectivity and other conditions

Battery capacity and power explained

Each battery has a published usable capacity of 5.0 kWh. Energy capacity describes how much energy can be stored; output power describes how quickly the battery can supply it.

The default continuous output rating is up to 3.84 kVA in single-phase configuration, or 3.84 kVA total in three-phase configuration, split into 1.28 kVA per phase. The installer can select other documented output ratings during commissioning, so confirm the rating of the quoted system.

kVA measures apparent power, while kW measures active power. These have the same numerical value at a power factor of one; they should not be treated as interchangeable under all load conditions.

Dividing 5 kWh by a steady 1 kW load gives five hours by simple arithmetic. That is not a promised backup duration. Actual energy available to loads depends on reserve settings, demand, temperature, battery ageing and Enphase’s protective operating limits. The datasheet includes a 2% safety-critical limit and describes an additional 3% provision for overnight battery electronics.

Solar compatibility and AC coupling

The battery connects to the AC side of the home’s electrical system. Solar panels therefore need their own compatible solar inverter or microinverters; they do not connect directly to the battery as a DC solar array.

Enphase lists IQ Series Microinverters and third-party PV string inverters in its compatibility documentation. However, this does not mean that every existing solar inverter will work in every backup arrangement. Ask the installer to verify the complete design and the behaviour of solar generation during a power cut.

AC coupling can be useful when adding storage to an existing solar installation because solar conversion and battery conversion are separate. Existing equipment, metering and network requirements still need an individual assessment.

Single-phase and three-phase operation

FlexPhase supports both single-phase and three-phase configurations. The same battery’s output is distributed differently depending on how the installer configures it.

At the default three-phase rating, one unit provides up to 1.28 kVA continuously on each phase, not 3.84 kVA on every phase. The load on each phase matters when assessing household appliances and backup requirements.

The permitted rating, wiring, grid profile and number of batteries must be confirmed for the property. Do not assume that changing phase configuration is a setting the homeowner can safely change in the app.

Backup during power cuts

The manufacturer specifies IQ System Controller 3 INT for backup operation. It provides the equipment needed to separate the backup installation from the grid during an outage. A grid-tied battery installation without the required backup equipment should not be described as offering power-cut protection.

The supported design can prioritise essential circuits or provide wider household backup within the installed system’s limits. Available energy, continuous output, appliance starting demand and the phase arrangement determine what can operate.

Confirm which circuits will be backed up, the selected reserve level and whether the solar installation can recharge the battery during an outage. Backup does not guarantee that every appliance can run simultaneously or that power will last for a fixed number of days.

Expanding your storage

Adding compatible IQ Battery 5P with FlexPhase units increases the system’s storage in 5 kWh increments. Two units provide 10 kWh of published usable capacity and three provide 15 kWh before allowing for the system’s operating limits and reserve settings.

The supported number of units depends on circuit ratings, phase configuration, selected battery power ratings, gateway and controller limits, and local installation requirements. Your installer should specify the approved design rather than relying on a single maximum number for all homes.

Discuss expansion before the first installation so that space, cabling and electrical equipment can accommodate the intended future configuration. More storage needs enough solar generation or an appropriate charging window to be useful.

EV charging and household demand

The battery can contribute energy to a suitably connected home EV charger. It is not itself a charging point, and the charger must be supplied separately.

A single battery’s default single-phase continuous rating of 3.84 kVA is below the demand of a 7 kW charger operating at full power. In normal grid-connected operation, the grid may supply the remaining demand, subject to the complete design. Full-power EV charging during an outage needs a separate assessment.

Compare direct off-peak electric vehicle (EV) charging with using energy stored in the home battery. Moving electricity through the battery introduces conversion losses. Charger controls, solar charging features and tariff integration should be verified for the exact equipment and UK installation.

App, tariffs and energy management

The Enphase App provides system monitoring and controls, including visibility of battery charge and household energy flows where the required metering is installed. Available operating profiles depend on the system, software and region.

Self-consumption can store surplus solar for later household use. Suitable tariff-based operation can shift electricity purchases from more expensive periods to cheaper periods. Savings depend on electricity rates, demand, losses and the value of exported solar.

The manufacturer lists 90% AC round-trip efficiency and 96% battery-module DC round-trip efficiency at the beginning of life. These measure different boundaries; the higher DC figure should not be presented as the complete AC system’s efficiency.

Internet connectivity supports remote monitoring, diagnostics and firmware updates. Do not assume that every advertised AI or virtual power plant feature is available in the UK; confirm the specific service before purchase.

UK pricing and quotation inclusions

Compare the complete installed cost rather than the battery-only price. The number of batteries, mounting arrangements, gateway, communications, metering, backup controller and electrical work affect the total.

Ask for a written quotation identifying IQ Battery 5P with FlexPhase, the exact product code, selected power rating and phase configuration. It should also state whether backup is included and list installation, commissioning, delivery and any applicable tax charges.

Installation and care

Each battery measures 980 × 550 × 188 mm (height × width × depth). Its total installed weight is 83 kg; the manufacturer separately lists a lifting weight of 69.5 kg. These are different figures and should not be confused.

The battery enclosure is IP55-rated and supports indoor or outdoor installation. Wall-mount equipment is included; the optional pedestal is sold separately. An Enphase-certified installer must assess the mounting surface, clearances, access and environmental conditions. Installation, troubleshooting and replacement must be carried out by an Enphase-certified installer.

The specified ambient operating range is −20°C to 50°C for charging and −20°C to 55°C for discharging. Charging power is reduced below 15°C and above 45°C; discharging power is reduced below 5°C and above 50°C. Being inside the operating range does not guarantee full rated power.

Keep vents clear and avoid placing objects on the equipment. The owner’s guide recommends a dry cloth or one slightly dampened with water, without solvents or harsh chemicals. Repairs and servicing should be arranged through the installer or Enphase.

Warranty and support

The supplied warranty, effective from 15 September 2025, covers the stated products installed in England, Scotland and Wales. For IQ Battery 5P with FlexPhase, the limited warranty runs until the earlier of 15 years from activation or 6,000 discharged cycles.

Subject to its conditions, the warranty specifies capacity retention of at least 70% of the battery’s nameplate rating at the end of year ten and 60% at the end of year fifteen, within the applicable warranty period. This is not a promise of unchanged capacity throughout ownership.

The warranty requires continuous internet connectivity, except for interruptions outside the owner’s reasonable control, and excludes batteries activated after their labelled ‘Energize by’ date. Retain the purchase and commissioning records.

Associated equipment has different warranty periods. The supplied schedule lists ten years for the covered IQ System Controller and five years for the listed gateway, communications and other accessories. Confirm the exact SKU and applicable cover, particularly for installations outside England, Scotland and Wales.

Is IQ Battery 5P with FlexPhase right for your home?

This battery merits consideration if you want AC-coupled storage, 5 kWh capacity increments and a configuration suitable for a single-phase or three-phase property. It may be relevant to an existing Enphase solar installation or another compatible solar system.

For three-phase homes, assess the demand on each phase rather than looking only at total output. For households seeking backup, include the controller and circuit design in the comparison from the start.

Compare the complete installed price, expected energy use, permitted output, support arrangements and warranty conditions with alternative systems. The appropriate configuration depends on your household rather than the battery capacity alone.

Frequently Asked Questions

Question	Answer
Does FlexPhase mean 3.84 kVA on each phase?	No. At the default three-phase rating, one unit provides 3.84 kVA total, or 1.28 kVA per phase
Is a solar inverter built into the battery?	The battery contains its own battery microinverters. Solar panels still require a compatible solar inverter or rooftop microinverters
Does purchasing the battery include backup?	No. Backup operation requires the appropriate IQ System Controller and a correctly designed installation
How much storage do two batteries provide?	Two units provide 10 kWh of published usable capacity, subject to reserve settings and protective operating limits
Can it work with existing solar?	Potentially. Enphase lists compatible solar options, but the installer must verify the exact equipment and intended backup behaviour
Can one unit run a 7 kW EV charger at full power?	Its default single-phase continuous rating is 3.84 kVA, below that demand. Grid-connected and backup operation need different assessments
Is the battery warranty an unconditional 15 years?	No. It ends at 15 years from activation or 6,000 discharged cycles, whichever occurs first, and is subject to other terms

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