Tesla Powerwall 3 vs. Enphase 5P vs. FranklinWH aPower 2

Quick answer: there is no universal winner—compare the installed design.

There is no universal winner among Tesla Powerwall 3, Enphase IQ Battery 5P and FranklinWH aPower 2. Powerwall 3 combines 13.5 kWh with selectable output up to 11.5 kW and an integrated solar inverter; IQ Battery 5P uses smaller 5.0 kWh, 3.84 kW modules; and aPower 2 provides 15 kWh and 10 kW in one AC-coupled unit. Those specifications describe products, not whether an installed design will meet a particular home's backup loads.

Choose from a written load calculation, outage-runtime goal, solar and generator compatibility check, single-line diagram, permitted equipment list, installed cash price and service plan. A larger energy number does not prove that a system can start an air conditioner, while a higher power rating does not prove that it can sustain a long outage.

Start with energy, power and motor-start demand

Kilowatt-hours (kWh) measure stored energy; kilowatts (kW) measure real-power delivery. Startup demand can briefly exceed an appliance's running load, so a motor-start calculation matters for air conditioners, well pumps and other large equipment. Apparent power in kVA is not automatically interchangeable with real power in kW; the equipment rating, power factor and configured limits must be compared on the same basis.

Runtime is also a load-management problem. As a simple illustration, 15 kWh divided by a constant 1.5 kW load equals ten hours before conversion losses, the operating reserve and changing household use. It is not a forecast or warranty. Ask the installer to show hourly essential-load assumptions and whether solar can recharge the battery while the grid is down.

Tesla Powerwall 3: integrated solar inverter and high single-unit output

Tesla's current U.S. Powerwall 3 datasheet lists 13.5 kWh of nominal battery energy and selectable nominal AC output settings of 5.8, 7.6, 10 or 11.5 kW. It also documents an integrated solar inverter and expansion architecture. The selected output and overcurrent protection must match the approved design; 11.5 kW should not be assumed from the product name alone.

The integrated architecture may simplify some new solar-plus-storage designs. For an existing array, require confirmation of module strings, inverter topology, gateway or Backup Switch, outage recharge behavior and any equipment that will be replaced. One Powerwall 3 does not guarantee whole-home backup or unlimited runtime.

Enphase IQ Battery 5P: smaller modules and granular expansion

Enphase's U.S. product information lists 5.0 kWh of usable energy and a 3.84 kW continuous power rating per IQ Battery 5P, with embedded grid-forming microinverters. Three units total 15 kWh of rated usable capacity and 11.52 kW of summed product-level continuous power before system design constraints, reserve settings and losses.

Five-kWh increments can help size selected-circuit backup and may fit homes already using compatible Enphase equipment. Multiple batteries also change wall area, wiring, controller, communications, labor and installed price. Confirm the exact battery SKU, IQ System Controller or other control equipment, permitted configuration and warranty activation requirements.

FranklinWH aPower 2: more energy in one AC-coupled unit

FranklinWH's current aPower 2 datasheet lists 15 kWh of battery energy and 10 kW continuous discharge power. The AC-coupled battery works with FranklinWH control equipment and supports expansion. The current manufacturer material identifies a 15-year or 60 MWh-throughput warranty, subject to the written terms and eligible installation.

AC coupling can be useful in a retrofit, but it is not proof of compatibility with every existing solar inverter, generator, service panel or utility program. Ask for the aGate configuration, startup-load calculation, equipment clearances, communications path and single-line diagram for the actual home.

Compare the complete installation—not three battery boxes

Every quote should identify batteries, gateway or controller, transfer equipment, backed-up circuits, load controls, subpanel work, electrical-service upgrades, communications, permits, utility steps, taxes and labor. California's Energy Storage Permitting Guidebook explains that behind-the-meter storage must meet applicable code and local authority requirements; a product datasheet is not a permit.

Give each installer the same recent interval-use data, essential-circuit list and outage goal. Require a cash price separate from financing, a rate-specific dispatch model for bill-shifting claims and written assumptions for solar production during outages. Backup capability alone does not prove savings or payback.

Read the warranty and service path before choosing the brand

Tesla's current U.S. material describes a 10-year Powerwall warranty; Enphase's U.S. IQ Battery 5P limited warranty identifies 15 years or 6,000 discharged cycles; and FranklinWH describes 15 years or 60 MWh throughput for aPower 2. These are not interchangeable promises. Capacity retention, usage profile, activation, communications, transfer, labor and exclusions must be read in each applicable document.

Ask who performs diagnosis, who pays travel, labor and shipping, whether an authorized installer is required and what happens if the original installer closes. Keep the signed warranty, serial numbers, permitted plans, inspection, commissioning record and monitoring-owner access. A long equipment warranty without a workable local service plan can still produce delay and out-of-pocket cost.

Use one scorecard for all three proposals

A defensible comparison records: usable energy; continuous, peak and motor-start capability; reserve setting; outage solar recharge; required controller; expansion limits; generator compatibility; installed cash price; warranty; service responsibility; and local permit or utility conditions. Mark any unanswered item as unknown instead of giving it a favorable assumption.

Powerwall 3 can fit an integrated design needing high single-unit output; IQ Battery 5P can fit modular increments and a compatible Enphase ecosystem; aPower 2 can fit a larger single-unit AC-coupled design. These are possible fits, not rankings or endorsements. The best proposal is the one that meets the home's documented loads and service needs at a transparent total cost.

A 2026 financing reminder

For new qualifying homeowner installations placed in service after December 31, 2025, the former federal Residential Clean Energy Credit under section 25D is not available, according to current IRS guidance. Do not let a salesperson reduce your quoted 2026 battery price by an assumed 30% homeowner credit. Different business or utility programs have separate requirements and should never be presumed available.

Compare the installation handover, not only the hardware

Ask each bidder to describe the same handover demonstration. The homeowner should be shown the backed-up circuits, ordinary operating mode, reserve controls, relevant alerts and the official support route. Request a written explanation of what changes during an outage and which loads may be disconnected or restricted. The installer should perform any approved commissioning demonstration; the homeowner should not improvise an outage test by operating electrical equipment without appropriate instructions.

Then compare service continuity. Who sees a fault, who can access diagnostics with your authorization, and what happens if the original installer stops offering service? Ask how production and battery history can be saved and how ownership access transfers with the house. These questions do not choose a brand by themselves. They make the complete proposals easier to compare because an understandable, supportable installation has value beyond its battery nameplate.

Frequently asked questions

Questions worth asking

• Which backup circuits and motor loads can each design actually support?
• What usable capacity and continuous output are configured—not just advertised?
• Can existing solar recharge the battery during an outage?
• What is the total installed cash price including gateways and electrical work?
• What labor, throughput and capacity limitations appear in the written warranty?