Solar Battery Cost Calculator
A 13.5 usable kilowatt-hour home battery runs about $18,395 in Atlanta — $12,447 to $24,343 — retrofitted to solar that is already up. ⚠️ Two things nobody leads with: usable is not nameplate — that is 15 kWh on the box — and a battery does not back up a house. It backs up a subpanel of circuits you choose, which on essentials lasts 38.6 hours and with air conditioning lasts 6.4.
Estimate the cost for your home
Estimated cost of the battery, installed
$18,532
typical · range $12,579 to $24,485 · 13.5 kWh usable (15 nameplate) · 38.6 hours of backup · $1,373 per usable kWh
Adding storage to an array that is already up costs more than including it at the start, and the reason is electrical rather than commercial: the existing system makes alternating current and the battery stores direct current, so a retrofit needs a second conversion stage of its own. It is still usually better than replacing a working inverter, and a retrofit quote should show it as its own line.
Labour priced at national wages. Enter a ZIP code to price it for your area. 90% of this figure comes from modelled material prices — each line shows its own uncertainty.
Priced from bls.gov Aug 2026how every line is sourced
The one input that changes the answer for you.
The configuration that makes a battery genuinely useful, and the one most people end up on after the first outage. A fridge, a few lighting circuits, the internet and the controls for gas heating together draw very little, so a battery lasts days rather than hours.
The usual answer and normally the cheapest: a solid wall, short runs to the panel, and out of the weather. ⚠️ In a garage that gets genuinely cold or genuinely hot, temperature matters more than people expect — a lithium battery loses usable capacity in the cold and ages faster in heat.
| On a garage wall | $18,532 |
|---|---|
| Outside, in a rated enclosure | $19,902 |
| Inside conditioned space, in a utility room | $18,917 |
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The figure above is already calculated. Each step just makes it more yours, and you can stop at any of them.
A battery does not back up a house
| What stays on | Average draw | It lasts | Cost |
|---|---|---|---|
| Essentials | 350 W | 38.6 h (1.6 d) | $18,532 |
| Essentials plus outlets, the microwave and a well pump | 750 W | 18 h (0.8 d) | $18,801 |
| Most of the house, including air conditioning | 2100 W | 6.4 h (0.3 d) | $19,205 |
This is the sentence almost nobody says out loud, and it decides whether you are happy with what you bought. A home battery backs up a subpanel, not a house — the circuits you choose are physically moved into a second panel that the battery feeds, and everything else goes dark. ⚠️ Choosing which ones is the real design decision of the whole project, and the big loads generally should not be on it: an electric range, a dryer, an electric water heater or central air conditioning will each empty a battery in an afternoon. Notice how little the price changes across this table and how much the duration does. What you are buying with the extra circuits is not capability — it is a much shorter outage.
Against a generator, from our own two models
| This battery | $18,532 |
|---|---|
| A standby generator instead | $12,174 |
| The generator is | $6,358 cheaper |
Both figures come from models on this site at the same BLS wages, which is the only reason they can be put side by side — and the answer surprises people who have been shopping for batteries. ⚠️ They are not interchangeable products, and the money is the least interesting difference. A generator runs indefinitely as long as it has fuel, and it is loud, it needs servicing, and it takes a few seconds to start. A battery is silent, needs nothing, works the instant the grid drops — and then it runs out. Which one is right depends on whether your outages are four hours or four days, and that is a question about your utility rather than about the hardware. Our whole house generator page prices the other one properly.
| Line item | Qty | Cost | Source |
|---|---|---|---|
| Permit, and the utility notification1 per installation | 1each | $280–$1,100 | estimated±59% |
| The battery itselfusable kilowatt-hours | 13.5kWh | $7,560–$13,500 | estimated±28% |
| Backup gateway and automatic transfer1 per installation | 1each | $1,400–$3,400 | estimated±42% |
| Protected-loads subpanel, and moving circuits into it1 per installation | 1each | $420–$1,300 | estimated±51% |
| Protected-loads subpanel, and moving circuits — labourcircuits × 1.1 hours + 5 hours | 11.6hour | $684–$735 | sourced |
| AC coupling, to add storage to solar that already exists1 when a battery is retrofitted to existing solar | 1each | $900–$2,600 | estimated±49% |
| Wall mounting in a garage1 when it goes on a garage wall | 1each | $190–$620 | estimated±53% |
| Installation, connection and commissioningusable kilowatt-hours × 0.55 hours + 12 hours | 19.4hour | $1,144–$1,229 | sourced |
| Total | $12,579–$24,485 | ±32% |
Where these numbers come from
- It backs up a subpanel, not a house
- This is the sentence that decides whether somebody is happy with what they bought, and it is rarely said plainly. A home battery feeds a second, smaller panel — the circuits you want alive in an outage are physically moved into it, and everything else stays on the main panel and goes dark. Choosing which circuits is the real design work of the whole project, and the big loads should generally not be among them: an electric range, a dryer, an electric water heater or central air conditioning will each empty a battery in an afternoon. ⚠️ On essentials — fridge, some lighting, the internet, gas heating controls — this battery runs 38.6 hours, which is 1.6 days. Back up most of the house and the same battery runs 6.4. Notice how little the price moves between those and how much the duration does: what more circuits buy is a much shorter outage.
- Against a generator, from two of our own models
- “Is it worth it” is best answered by putting it beside the other way of having power when the grid fails, calculated here at the same BLS wages: $18,395 for this battery against $12,056 on our whole house generator cost calculator. ⚠️ The money is the least interesting difference, and the answer surprises people who have been shopping for batteries. A generator runs indefinitely as long as it has fuel, and it is loud, needs servicing, and takes a few seconds to start. A battery is silent, needs nothing, works the instant the grid drops — and then it runs out. Which is right depends on whether your outages are four hours or four days, and that is a question about your utility rather than about the hardware. One more thing worth saying because almost nobody expects it: solar panels on their own do not keep the lights on in a power cut. The inverter shuts down so it cannot energise a line a crew is working on.
- Usable, nameplate, and the cold
- A battery cannot be run flat — a reserve protects the cells — so the capacity on the box is bigger than the capacity you get. This model works at 90% usable and publishes both: 13.5 kWh usable is about 15 kWh of nameplate, and comparing two batteries on nameplate compares the wrong number. Cost per usable kilowatt-hour falls steeply with size — $2,301 at 5 kWh against $1,087 at 27 — because the gateway, the subpanel and most of the labour are the same whatever the battery. ⚠️ And the cold: a lithium battery loses usable capacity below about freezing and will not charge at all without heating, so an unheated garage in a cold state gives you the smallest battery exactly when the outage is most likely. Conditioning the space is $1,000 here, which is far cheaper than buying capacity to make up the loss. Where it goes matters too: $18,395 on a garage wall against $19,765 outside in a rated enclosure.
- What we will not tell you, and where the numbers come from
- ⚠️ Whether a battery pays for itself outside of outages depends entirely on your tariff — time-of-use spreads, demand charges, and what your utility pays for exports — and those vary by utility and change. There is no national figure to publish and inventing one would be the least reliable thing on this page. For scale only, the EIA put the average US residential price at 18.11 cents per kilowatt-hour for May 2026, year to date (retrieved 2026-08-25); your own bill is the number that matters. On the federal credit, this page prices work and is not tax advice: IRS, Residential Clean Energy Credit (retrieved 2026-08-24) says the residential clean energy credit — which covered storage as well as panels — applies to property installed through December 31, 2025 and is not available for anything placed in service after that. US Department of Energy, Homeowner’s Guide to Going Solar (retrieved 2026-08-24) is the federal starting point for the wider decision. Wages from BLS OEWS, May 2025, retrieved 2026-08-20, for electricians, benefit-loaded from BLS ECEC. The panels themselves are priced on our solar panel installation cost calculator.
- Material prices
- Modelled estimates, not sourced prices. No public, machine-readable source of US residential material prices exists, and we would rather say so than pretend otherwise. Each line carries its own uncertainty band. How we estimate them.
Contractor overhead and profit applied at 33–43% over direct cost. Data last reviewed 2026-08-24.
What this figure does not include
- Anything about your tax position
- ⚠️ Residential storage was covered by the federal residential clean energy credit, and the IRS page — read on 2026-08-24 — says that credit covers property installed through 31 December 2025 and is not available for anything placed in service after that. This page prices work, not tax positions. Check the IRS and a tax professional; state and utility programmes are separate and are not modelled here.
- The solar panels themselves
- Priced on our solar panel installation page. A battery works with or without solar — without it, it charges from the grid when electricity is cheap and runs the house when it is expensive, which is a completely different economic case.
- What your utility pays for exports, or charges at peak
- Whether a battery pays for itself outside of outages depends entirely on your tariff: time-of-use spreads, demand charges and export rates vary by utility and change. There is no national figure to publish and inventing one would be the least reliable thing on this page.
- A second battery
- Backing up air conditioning or an electric range realistically means more than one, and the cost is close to linear in the battery and much less than linear in everything else — the gateway, the subpanel and most of the labour are already paid for.
- A service upgrade if the panel is full
- The subpanel has to be fed and the gateway has to fit. On an old or full panel that becomes a service upgrade, priced on our electrical panel page.
- Replacing it at the end of its life
- A home battery has a warranty measured in years and cycles, and it does not last as long as the panels beside it. The replacement is a real future cost and it is not in this figure.
Questions people actually ask
How much does a solar battery cost?
$18,395 on this model in Atlanta for 13.5 usable kilowatt-hours retrofitted to an existing array — $12,447 to $24,343, or $1,363 per usable kWh. ⚠️ The battery itself is well under half of that. The rest is the backup gateway that disconnects you from the grid when it fails, a protected-loads subpanel, the mounting and the electrical work — and none of it scales with capacity, which is why 5 kWh costs $2,301 per usable kWh and 27 kWh costs $1,087. A second battery bought later is far worse value than the same capacity bought at once.
How much does it cost to add a battery to existing solar?
About $1,750 more than it would have cost to include at the start — $18,395 here against $16,645. ⚠️ The reason is electrical rather than commercial, which is worth knowing so you can tell a fair quote from a padded one: an existing array makes alternating current and a battery stores direct current, so a retrofit needs its own conversion stage where a battery designed in from the beginning could have shared one. It is still normally the right move rather than replacing a working inverter, and a retrofit quote should show it as its own line. If you are installing solar now and think you might want storage later, this is the number that argues for deciding now.
Is it worth getting a battery for solar panels?
Two things decide it, and neither is the price of the battery. ⚠️ The first: solar without storage does not keep your lights on in a power cut. The inverter shuts down so it cannot energise a line somebody is working on, so a house with panels and no battery is as dark as the house next door — which surprises almost everyone. The second: a battery does not back up a house, it backs up a subpanel of circuits you choose. On essentials this one runs 38.6 hours; back up most of the house including air conditioning and it runs 6.4. And against the other way of having power, our own models give $18,395 for this battery and $12,056 for a standby generator — which runs indefinitely on fuel, and is loud.
How much does a typical solar battery cost?
The trouble with "typical" is that batteries are advertised on nameplate capacity and sold on usable capacity, and those are different numbers. ⚠️ This model works in usable kilowatt-hours because usable is what you get: 13.5 kWh usable is about 15 kWh of nameplate, because a reserve is held back to protect the cells. Comparing two batteries on their nameplate figures compares the wrong number. On that basis the range here runs from $11,504 for 5 usable kWh to $29,351 for 27. One more thing that changes the answer and is nobody's headline figure: in a garage that freezes, add $1,000 to condition the space, or accept a battery that shrinks in winter.
Taken from Google’s “people also ask” results for this search on 2026-08-24, not invented.
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