Tesla Powerwall 3 Specs: Capacity, Power, Efficiency, And Price (2026)
The Tesla Powerwall 3 is a 13.5 kWh home battery with a built-in solar inverter, 11.5 kW continuous power output, and 97.5% round-trip efficiency. It replaced the Powerwall 2 in 2024 with a complete redesign: one box instead of two, more than double the continuous power, and no separate Gateway required. Here are the full specs, what changed, how many you need, and what it actually costs installed.
Complete Powerwall 3 Specifications
| Specification | Value |
|---|---|
| Usable energy capacity | 13.5 kWh |
| Continuous power (off-grid) | 11.5 kW |
| Continuous power (on-grid) | 10 kW |
| Peak power (10 seconds) | 22 kW |
| Solar input | Up to 11.5 kW DC |
| Battery chemistry | NMC (nickel manganese cobalt) |
| Round-trip efficiency | 97.5% |
| Dimensions | 43.25" x 24" x 7.6" (1,098 x 609 x 193 mm) |
| Weight | 287 lbs (130 kg) |
| Ingress protection | IP67 (dust-tight, submersible) |
| Operating temperature | -4 to 122 degrees F (-20 to 50 degrees C) |
| Mounting | Wall or floor, indoor or outdoor |
| Warranty | 10 years, 70% capacity retention, unlimited cycles |
| Scalability | Up to 4 units per system |
The 13.5 kWh figure is usable capacity, not total. Tesla manages the state-of-charge window internally, so you do not need to derate it yourself as you would with a generic lithium battery where you might limit depth of discharge to 80% or 90%.
The 11.5 kW continuous output is the standout number. This is the amount of power the Powerwall 3 can sustain indefinitely, and it is enough to run most US homes during an outage without any load shedding. For context, the average American home peaks at around 5 to 7 kW during normal use.
What Changed From Powerwall 2
The Powerwall 3 is not an incremental update. It is a ground-up redesign.
Built-in inverter. The Powerwall 2 was just a battery. It needed a separate Tesla Backup Gateway (or Gateway 2) to handle solar input and grid switching. The Powerwall 3 integrates the solar inverter, battery inverter, and automatic transfer switch into a single unit. This simplifies installation, reduces failure points, and saves wall space.
More than double the continuous power. The Powerwall 2 output 5 kW continuous, which was often the bottleneck during outages. An air conditioner compressor alone can draw 3 to 5 kW on startup. The Powerwall 3 pushes 11.5 kW continuous (22 kW peak), making whole-home backup realistic with a single unit for smaller homes.
Higher round-trip efficiency. The Powerwall 2 was rated at 90% round-trip efficiency. The Powerwall 3 reaches 97.5%. That improvement comes largely from eliminating one conversion step, since the solar DC goes directly into the battery without an external inverter in the path.
Same capacity. Usable capacity stayed at 13.5 kWh. Tesla focused the upgrade on power and integration rather than raw storage.
| Specification | Powerwall 2 | Powerwall 3 |
|---|---|---|
| Usable capacity | 13.5 kWh | 13.5 kWh |
| Continuous power | 5 kW | 11.5 kW |
| Peak power | 7 kW | 22 kW |
| Round-trip efficiency | 90% | 97.5% |
| Built-in inverter | No (needed Gateway) | Yes |
| Weight | 251 lbs | 287 lbs |
How Many Powerwalls Do You Need?
The answer depends on what you want to keep running during an outage and how long you need to last.
One Powerwall (13.5 kWh, 11.5 kW): Covers essential loads for most homes. A refrigerator (150 W), lights (200 W), WiFi router (15 W), phone charging (20 W), and a few outlets add up to roughly 400 to 500 W sustained. At that draw, a single Powerwall lasts 27 to 34 hours. Add a window AC unit (1,200 W) and it drops to around 8 hours.
Two Powerwalls (27 kWh, 23 kW): Covers whole-home backup for a typical 2,000 to 2,500 sq ft house. You can run central HVAC, kitchen appliances, washer/dryer, and general lighting. The 23 kW combined continuous output handles startup surges from compressors and motors. Runtime depends on usage but expect 12 to 24 hours without solar recharging.
Three Powerwalls (40.5 kWh, 34.5 kW): Needed for large homes, homes with electric heating, or homes that need multi-day backup without solar. Also necessary if you want to charge an EV at a useful rate during an outage.
If you have solar panels, the calculus changes. On a sunny day, your panels recharge the batteries during daylight hours, effectively extending backup indefinitely for moderate loads. The key constraint then becomes the overnight gap.
Powerwall 3 Price
Tesla does not publish a single fixed price. The installed cost varies by region, installer, and whether you are combining with a solar installation.
| Configuration | Estimated installed cost (before tax credit) | After 30% tax credit |
|---|---|---|
| 1 Powerwall | $9,200 - $12,000 | $6,400 - $8,400 |
| 2 Powerwalls | $17,000 - $22,000 | $11,900 - $15,400 |
| 3 Powerwalls | $25,000 - $32,000 | $17,500 - $22,400 |
The federal Residential Clean Energy Credit (Section 25D) covers 30% of the total installed cost of a battery storage system, including labor and materials. The battery does not need to be paired with solar panels to qualify, though it must be installed at a primary or secondary residence.
Some states offer additional incentives. California's SGIP (Self-Generation Incentive Program) can reduce costs by another $1,000 to $4,000 depending on your utility territory and income level.
Price per kWh. At $9,200 to $12,000 for 13.5 kWh, the Powerwall 3 costs $681 to $889 per kWh before incentives. After the 30% federal credit, it drops to $474 to $622 per kWh. This is competitive with other integrated home battery systems, though modular LFP options from manufacturers like EG4 and Sol-Ark can beat it on raw per-kWh cost if you are willing to handle more complex installation.
Pros And Cons
Pros:
- High continuous power (11.5 kW) handles whole-home backup without load management
- Built-in inverter simplifies installation and reduces component count
- 97.5% round-trip efficiency means minimal energy loss
- IP67 rating allows true outdoor installation
- Tesla app provides detailed monitoring and Storm Watch (pre-charges before severe weather)
- Stacks up to 4 units for large homes
Cons:
- NMC chemistry has shorter cycle life than LFP alternatives (though Tesla's warranty covers 10 years unlimited cycles)
- Only available through Tesla-certified installers, limiting competition on installation pricing
- 10-year warranty is shorter than Enphase (15 years) and some LFP competitors
- No direct DC coupling option for third-party inverters
- Tesla's installation timelines can be unpredictable depending on region
Powerwall 3 Vs Competitors At A Glance
| Battery | Capacity | Continuous power | Chemistry | Warranty | Estimated $/kWh installed |
|---|---|---|---|---|---|
| Tesla Powerwall 3 | 13.5 kWh | 11.5 kW | NMC | 10 years | $681 - $889 |
| Enphase IQ Battery 5P | 5 kWh | 3.84 kW | LFP | 15 years | $800 - $1,000 |
| Generac PWRcell | 9 - 18 kWh | 4.5 - 9 kW | NMC | 10 years | $700 - $900 |
| Franklin WH aPower | 13.6 kWh | 10 kW | LFP | 12 years | $750 - $950 |
| SolarEdge Home Battery | 9.7 kWh | 5 kW | LFP | 10 years | $800 - $1,000 |
The Powerwall 3's combination of high continuous power and integrated inverter makes it particularly strong for whole-home backup. The main tradeoff is the 10-year warranty with NMC chemistry versus the longer warranties offered by LFP-based competitors.
Calculator
Use this calculator to estimate charging times and solar panel requirements for battery systems:
| Chemistry | Efficiency | Cycle Life | Panel Watts |
|---|---|---|---|
| Lithium (LiFePO4) | 95% | 3,000–5,000 | 252 W |
| Deep Cycle AGM | 85% | 500–1,000 | 283 W |
| Lead-Acid Flooded | 80% | 300–500 | 300 W |
Tap to see sensitivity analysisSensitivity analysis
| Scenario | Value |
|---|---|
| Low (-20%) | 202 W |
| Expected | 252 W |
| High (+20%) | 302 W |
Battery chemistry has the biggest effect \u2014 switching from lead-acid to lithium reduces required panel watts by ~20%.
Keep Reading
Frequently Asked Questions
What is the usable capacity of the Tesla Powerwall 3?
How much does a Tesla Powerwall 3 cost installed?
How many Powerwalls do I need for whole-home backup?
Does the Powerwall 3 have a built-in inverter?
What is the warranty on the Tesla Powerwall 3?
What battery chemistry does the Powerwall 3 use?
Can I install Powerwall 3 outdoors?
What is the round-trip efficiency of the Powerwall 3?
How does the Powerwall 3 compare to the Powerwall 2?
Sources
- Tesla Powerwall 3 Official Product Page (specifications and ordering)
- Tesla Powerwall 3 Datasheet (PDF with full electrical and mechanical specs)
- DOE Battery Energy Storage Technical Reference (battery chemistry and performance)
- NREL — Cost Projections for Utility-Scale Battery Storage (2024 update)
- EnergySage — Tesla Powerwall 3 Review and Pricing Data (installer survey)
- IRS — Residential Clean Energy Credit (Section 25D, 30% battery tax credit)
- EIA — Battery Storage in the United States (installed capacity and trends)