How much does a solar battery cost to install?

Our installed ranges are $2,500–$6,000 for a portable power station with its transfer hookup and $6,000–$15,000+ for whole-home battery backup. The written quote depends on the equipment, your panel, and the loads you back up. Estimates are free.

Will my solar panels work in an outage without a battery?

No. Grid-tied solar is designed to shut off when the grid goes down. Backup takes a battery and transfer equipment that isolate your home from the grid.

What does UL 9540 mean on a home battery?

It means the complete energy storage system was evaluated to the UL safety standard for energy storage, including its controls, protection, enclosure, and grid interaction. We connect listed systems.

Can I use a portable power station instead of a whole-home battery?

Yes, for essential circuits. We install an inlet and a transfer switch or listed interlock so the power station feeds chosen circuits safely. It will not run the whole house or switch over automatically.

Solar batteries

Solar Battery Equipment for Northern Virginia Homes

Name: AJ Long Electric
Address: 2724 Dorr Ave, Suite 102, Fairfax, VA, 22031, US
Telephone: (571) 444-6886

We install two classes of battery equipment: portable power stations with a transfer connection, and whole-home batteries wired into the service. Installed prices run $2,500–$6,000 for a portable setup and $6,000–$15,000+ for whole-home backup.

Get a roof study Call (571) 444-6886

Reviewed 2026-09-24

Brick home with rooftop solar beside an open garage containing two wall-mounted battery cabinets and closed electrical equipment

Google reviews

1,463 across four profiles

Family-owned

Since 1996

Licensed and insured

VA 2705031092

On every install

Master electrician on site

Backed by

Workmanship warranty

Answer first

Which battery equipment fits your home

Pick the class first, then the product. A portable power station covers a few essential circuits through an inlet and transfer device. A whole-home battery is listed energy storage, wired permanently, that switches your home to islanded mode automatically when the grid drops. Either one needs transfer equipment, because without it a grid-tied solar array shuts off in an outage by design.

Portable power station plus install: $2,500–$6,000.
Whole-home battery plus install: $6,000–$15,000+.
A permanently installed battery should carry a UL 9540 listing for the complete system. We check it before we quote.
Transfer equipment isolates your home from the grid before the battery or solar feeds it.

Two classes of battery equipment

The class decides what you get in an outage, what the installation involves, and what it costs. Brand comes after.

Portable vs whole-home battery equipment
	Portable power station	Whole-home battery
Installed range	$2,500–$6,000	$6,000–$15,000+
How it connects	Plugs into an exterior or garage inlet wired to a transfer switch or listed interlock	Wired permanently to the service with its own transfer equipment
What it runs	Circuits you choose: refrigerator, sump pump, furnace blower, lights, internet	A critical-loads panel or the whole home, depending on design
Switchover	Manual: you move the interlock or transfer switch	Automatic when the grid goes down
Charging from solar	Through the power station's own solar input, if it has one	From the rooftop array while islanded, when the system is designed for it

Prices are installed ranges from our published pricing. Your written quote is project-specific.

UL 9540: the listing we look for

UL 9540 is the safety standard for energy storage systems. UL describes it as covering the system as a whole: charging and discharging, protection and controls, enclosures, communication, and interaction with the utility grid. A related test method, UL 9540A, evaluates thermal runaway fire propagation in battery systems and is cited in NFPA 855. UL has also published UL 9540B for the added considerations of residential use.

For a battery installed in or on your home, we look for the UL 9540 listing on the complete system, not only on the cells. The listing and the manufacturer's installation instructions set where the battery may go, the clearances around it, and how it connects. The permit reviewer checks the same documents.

Transfer equipment is what makes backup work

The Department of Energy explains that grid-tied solar is designed to switch off when grid power cuts out. That protects utility workers from power feeding back into the lines. A battery does not change that by itself. The system needs equipment that disconnects your home from the grid first, and then lets the battery and the array run the house.

Whole-home battery systems use an automatic transfer device or backup gateway at the service. DOE notes that solar with battery storage automatically detects the loss of grid power and switches to islanded mode.
A critical-loads panel moves the circuits you choose to a separate panel the battery supports. That keeps a smaller battery from being drained by an electric range or a heat strip.
Portable power stations connect through an inlet box and a transfer switch or a listed interlock on your main panel. You flip it by hand. This is the same hookup we install for portable generators.
Panel capacity comes first. An older or full panel may need replacement before any transfer equipment goes in.

Batteries with a new or existing array

We design batteries into new solar systems and add them to arrays already on the roof, including arrays another company installed. The design starts with your panel, your inverter type, and the loads you want covered in an outage. A master electrician is on site for every solar project.

Rental and business owners: battery storage has its own federal foreign-entity threshold under Section 48E, 55 percent of equipment cost from other manufacturers for 2026 construction starts, and storage is not subject to the December 31, 2027 solar placed-in-service cutoff. This may matter for rental and business owners. Confirm with a CPA.

Straight answers

Questions

How much does a solar battery cost to install?: Our installed ranges are $2,500–$6,000 for a portable power station with its transfer hookup and $6,000–$15,000+ for whole-home battery backup. The written quote depends on the equipment, your panel, and the loads you back up. Estimates are free.
Will my solar panels work in an outage without a battery?: No. Grid-tied solar is designed to shut off when the grid goes down. Backup takes a battery and transfer equipment that isolate your home from the grid.
What does UL 9540 mean on a home battery?: It means the complete energy storage system was evaluated to the UL safety standard for energy storage, including its controls, protection, enclosure, and grid interaction. We connect listed systems.
Can I use a portable power station instead of a whole-home battery?: Yes, for essential circuits. We install an inlet and a transfer switch or listed interlock so the power station feeds chosen circuits safely. It will not run the whole house or switch over automatically.

Sources

Next step

Size a battery for your outage plan

Tell us what has to stay on. We check your panel and loads and give you a free written quote for the battery class that fits.