A home battery backup system stores 10–20 kWh of electricity and delivers 5–11.5 kW of continuous power, enough to run your essential circuits (refrigerator, lights, Wi-Fi, medical devices, and select HVAC equipment) for 8–24 hours during a grid outage. In 2026, the most popular residential batteries cost $8,000–$16,000 installed and qualify for the 30% federal tax credit when paired with solar.
Whether you're buying a battery for backup power, solar self-consumption, time-of-use arbitrage, or all three — this guide covers every major product on the market with real specs, pricing, and performance comparisons.
Why Home Batteries Took Off (2020–2026)
The residential battery market has grown from a niche curiosity to a mainstream product category. Several converging forces drove this shift:
Grid reliability is declining in many regions. Texas experienced winter storm failures in 2021, California faces rolling blackouts during heat waves, and severe weather events are increasing in frequency nationwide. According to the EIA, the average U.S. customer experienced over 8 hours of power interruption in 2023 — double the average from a decade earlier.
Meanwhile, net metering policies are eroding. California's NEM 3.0 (effective April 2023) slashed solar export credits from ~$0.30/kWh to ~$0.05–$0.08/kWh, making battery storage essential for California solar ROI. Hawaii, Nevada, and several other states have implemented similar changes.
The 30% federal Inflation Reduction Act tax credit (effective through 2032) now applies to standalone batteries — they no longer need to be paired with solar to qualify. This single policy change expanded the addressable market significantly.
Top Home Batteries Compared (2026)
| Battery | Capacity (kWh) | Continuous Output (kW) | Peak Output (kW) | Round-Trip Efficiency | Warranty | Installed Price |
|---|---|---|---|---|---|---|
| Tesla Powerwall 3 | 13.5 | 11.5 | 18.5 | 97.5% | 10 yr | $12,500–$15,500 |
| Enphase IQ 5P | 5.0 | 3.84 | 7.68 | 96% | 15 yr | $6,500–$8,500 |
| Franklin WH aPower | 13.6 | 10 | 18 | 96% | 12 yr | $12,000–$15,000 |
| Sonnen ecoLinx | 12–20 | 8 | 8 | 95% | 10 yr (15k cycles) | $15,000–$25,000 |
| LG RESU Prime | 16 | 9.6 | 11 | 95% | 10 yr | $11,000–$14,000 |
| Generac PWRcell | 9–18 | 4.5–9 | 7.6 | 96.5% | 10 yr | $10,000–$18,000 |
| SolarEdge Home Battery | 10 | 5 | 7.5 | 94.5% | 10 yr | $9,000–$12,000 |
| BYD HVS/HVM | 5.1–22.1 | 5–12.8 | 5–12.8 | 95.3% | 10 yr | $7,000–$16,000 |
Prices shown are typical installed costs including battery, gateway/transfer switch, electrical work, permitting, and labor. Your actual cost may vary by $1,000–$3,000 depending on your location, electrical panel condition, and installer. All prices are before the 30% federal tax credit.
Detailed Product Breakdowns
Tesla Powerwall 3
The Powerwall 3 is Tesla's third-generation home battery and the most popular residential battery in the U.S. by volume. Key improvements over the Powerwall 2 include an integrated solar inverter (eliminating the need for a separate inverter), higher continuous output (11.5 kW vs 5 kW), and Tesla's whole-home backup capability.
Standout specs:
- 13.5 kWh usable capacity
- 11.5 kW continuous / 18.5 kW peak (enough to start a central AC compressor)
- Built-in 11.5 kW solar inverter (handles up to ~15 kW of panels)
- 97.5% round-trip efficiency (DC-coupled)
- Storm Watch feature — auto-charges before severe weather using NWS data
- Stackable up to 4 units (54 kWh, 46 kW continuous)
Limitations: Requires the Tesla app ecosystem, limited installer network compared to Enphase, and whole-home backup requires Tesla Gateway 2 which adds cost. Availability can vary by region.
Best for: Homeowners who want whole-home backup with solar integration and don't mind the Tesla ecosystem.
Enphase IQ 5P
Enphase took a modular approach: each IQ 5P unit stores 5 kWh and delivers 3.84 kW continuous. You stack multiple units to reach your desired capacity and output. This makes Enphase the most flexible system for right-sizing.
Standout specs:
- 5 kWh per unit (stack 1–12 units for 5–60 kWh)
- 3.84 kW continuous per unit
- LFP (lithium iron phosphate) chemistry — safer, longer lifespan
- 15-year warranty (best in class)
- Pairs natively with Enphase microinverters
- Each unit is compact (96 lbs) and wall-mountable
Limitations: Lower per-unit output means you need 3+ units ($19,500–$25,500) for whole-home backup. Cost per kWh is higher than competitors at lower capacities.
Best for: Homeowners with Enphase microinverter solar systems who want modular, reliable backup with an industry-leading warranty.
Franklin WH aPower
Franklin Whole Home has rapidly gained market share with an all-in-one design that rivals Tesla's specs at similar pricing. The aPower includes a built-in transfer switch and smart electrical panel that can manage circuit-level backup priorities.
Standout specs:
- 13.6 kWh usable capacity
- 10 kW continuous / 18 kW peak
- Built-in 200A transfer switch and smart load management
- Works with any solar inverter brand (DC or AC coupled)
- Intuitive app with per-circuit monitoring and control
- Stackable up to 15 units
Limitations: Newer company with less track record than Tesla or Enphase. Installation requires Franklin-certified electricians.
Best for: Homeowners who want whole-home backup with smart load management and installer-brand flexibility.
Sonnen ecoLinx
Sonnen (now owned by Shell) targets the premium market with a smart home integration focus. The ecoLinx connects with smart home systems (Control4, Savant, Crestron) and offers intelligent energy management.
Standout specs:
- 12–20 kWh configurable capacity
- 15,000 cycle warranty (roughly 15+ years of daily cycling)
- LFP chemistry
- Integrated smart home control
- Sonnen virtual power plant participation (earn credits in some markets)
Limitations: Highest cost per kWh. Lower peak output (8 kW) may not start large AC compressors. Premium-only positioning limits installer availability.
Best for: High-end homes with smart home systems seeking premium build quality and long cycle life.
How to Size Your Home Battery
Step 1: Identify What You Want to Back Up
The most common approach is "essential loads" backup — running critical circuits during an outage while leaving high-draw items (electric dryer, oven, pool pump, EV charger) offline.
| Load | Watts (Running) | Daily kWh |
|---|---|---|
| Refrigerator | 150–400 | 1.5–3.5 |
| LED lighting (whole home) | 200–500 | 2.0–5.0 |
| Wi-Fi router + modem | 20–40 | 0.5–1.0 |
| Phone/laptop charging | 50–150 | 0.5–1.5 |
| Sump pump | 500–1,000 | 0.5–2.0 |
| Garage door opener | 500–700 | 0.1–0.2 |
| Gas furnace blower | 400–800 | 3.0–6.0 |
| Window AC unit | 500–1,500 | 4.0–12.0 |
| Central AC (3 ton) | 2,500–3,500 | 8.0–18.0 |
| Medical devices (CPAP, O2) | 50–400 | 0.5–3.5 |
| Well pump | 750–2,000 | 1.0–4.0 |
Step 2: Calculate Your Backup Duration
For most homeowners, 8–12 hours of essential backup is sufficient to ride through typical outages. If you experience multi-day outages (hurricanes, ice storms), you'll want either multiple batteries or a battery + solar combination.
Essential loads only (no HVAC): 5–8 kWh/day → one 13.5 kWh battery lasts 1.5–2.5 days
Essential loads + window AC: 10–15 kWh/day → one 13.5 kWh battery lasts ~1 day
Whole home including central AC: 25–40 kWh/day → need 2–3 batteries or battery + solar to sustain
Real scenario: A family in Houston with a 13.5 kWh Powerwall 3 and 8 kW solar array experienced a 3-day outage during a summer storm. With careful load management (running AC only during peak afternoon hours, turning off at night), the solar panels recharged the battery each day. They maintained refrigeration, lighting, internet, and 6–8 hours of AC daily throughout the outage.
Step 3: Match Output to Starting Loads
Continuous output (kW) matters as much as capacity (kWh). Large motors (AC compressors, well pumps, sump pumps) draw 3–5× their running wattage during startup. A battery with only 5 kW continuous output cannot start a central air conditioner.
| Equipment | Running Watts | Starting Watts | Min Battery Output Needed |
|---|---|---|---|
| Central AC (3 ton) | 3,000 | 9,000–12,000 | 10+ kW peak |
| Well pump (1 HP) | 1,000 | 3,000–4,000 | 5+ kW peak |
| Sump pump (1/2 HP) | 500 | 1,500–2,000 | 3+ kW peak |
| Refrigerator | 200 | 800–1,200 | 2+ kW peak |
Critical for AC backup: If you want your battery to power central air conditioning during an outage, you need a system with at least 10 kW peak output. Tesla Powerwall 3 (18.5 kW peak) and Franklin WH aPower (18 kW peak) can handle this. Most Enphase and Sonnen configurations cannot start a central AC compressor unless you stack 3+ units.
Battery Chemistry: LFP vs NMC
Two lithium-ion chemistries dominate the home battery market:
| Feature | LFP (Lithium Iron Phosphate) | NMC (Nickel Manganese Cobalt) |
|---|---|---|
| Cycle life | 5,000–10,000+ cycles | 3,000–5,000 cycles |
| Safety | Very stable, minimal thermal runaway risk | Stable with proper BMS, rare thermal events |
| Energy density | Lower (larger/heavier) | Higher (more compact) |
| Temperature tolerance | Better in high heat | More sensitive to heat |
| Cost trend | Dropping rapidly | Relatively stable |
| Used by | Enphase, Sonnen, BYD, Franklin WH | Tesla (Powerwall 2), LG, SolarEdge |
The industry is moving decisively toward LFP. Tesla's Powerwall 3 uses NMC but achieves excellent thermal management. Most new entrants use LFP chemistry.
For homeowners, the practical difference is warranty cycles. An LFP battery warranted for 10,000 cycles will easily handle daily cycling for 25+ years. An NMC battery warranted for 4,000 cycles will last about 10–12 years of daily cycling.
Real-World Cost Analysis
Scenario 1: Battery for Backup Only (No Solar)
- System: Tesla Powerwall 3 + Gateway
- Installed cost: $14,000
- Federal tax credit (30%): -$4,200
- Net cost: $9,800
- Value: Peace of mind, food preservation, medical device backup, work-from-home continuity
- Financial return: Minimal unless you have frequent outages costing you $500+ each (spoiled food, hotel stays, lost wages)
Scenario 2: Battery + Solar for TOU Arbitrage (California NEM 3.0)
- System: 8 kW solar + 13.5 kWh battery
- Installed cost: $30,000
- Federal tax credit: -$9,000
- Net cost: $21,000
- Annual savings: $2,800 (solar generation + TOU shifting)
- Payback: 7.5 years
- 25-year savings: $49,000
Under NEM 3.0, storing solar energy in a battery and discharging during peak hours (4–9 PM at $0.40–$0.55/kWh) instead of exporting at $0.05–$0.08/kWh generates $600–$1,200 in additional annual value compared to a solar-only system.
Scenario 3: Battery for Virtual Power Plant (VPP) Income
Several utilities and companies now offer VPP programs that pay you to share your battery capacity:
| VPP Program | Payment | Requirements |
|---|---|---|
| Tesla Virtual Power Plant (TX, CA) | $0.50–$2.00/kWh discharged | Powerwall + Tesla app |
| OhmConnect (CA) | Variable, up to $1,000/year | Compatible battery |
| Green Mountain Power (VT) | $850/year lease credit | Powerwall or equivalent |
| ConnectedSolutions (MA, CT, RI) | $225–$275/kWh enrolled/year | Participating batteries |
VPP programs can offset 15–30% of your battery cost over its lifetime. Check with your utility and battery manufacturer to see which programs are available in your area. Tesla's VPP program is the most widespread, but utility-specific programs often offer better per-kWh rates.
Scenario 4: Full Energy Independence (Off-Grid Capable)
- System: 12 kW solar + 3× Powerwall 3 (40.5 kWh) + generator backup
- Installed cost: $58,000–$72,000
- Federal tax credit: -$17,400–$21,600
- Net cost: $40,600–$50,400
This setup can sustain a typical home (including central AC) for 1–3 days without sun. With solar recharging, it can operate indefinitely in most climates. A small propane generator provides additional backup for extended cloudy periods.
Installation: What to Expect
Timeline
| Phase | Duration |
|---|---|
| Site assessment & quote | 1–2 weeks |
| Permitting | 2–6 weeks (varies by jurisdiction) |
| Equipment procurement | 1–4 weeks |
| Installation day | 4–8 hours |
| Utility inspection & permission to operate | 1–4 weeks |
| Total: | 6–16 weeks |
Installation Requirements
Your electrical panel must have space for a battery gateway or transfer switch. Homes with older 100A or 150A panels may need a panel upgrade ($2,000–$4,000), which can be rolled into the total cost and covered by the tax credit.
Batteries are typically installed in garages, exterior walls, or utility rooms. They need a well-ventilated space with temperatures between 32°F and 110°F for optimal performance. Most batteries are NEMA 3R rated for outdoor installation but perform best in temperature-controlled environments.
Permit and code requirements vary significantly by jurisdiction. Some areas require separate permits for battery storage systems. Your installer should handle all permitting, but verify this is included in your quote. The 2023 and 2026 NEC codes have specific requirements for battery disconnect switches and signage.
Battery vs. Generator: Which Is Better for Backup?
| Feature | Home Battery | Standby Generator |
|---|---|---|
| Fuel source | Electricity (solar/grid) | Natural gas / propane / diesel |
| Transfer time | Instant (<200ms) | 10–30 seconds |
| Noise | Silent | 60–75 dB |
| Maintenance | None | Oil changes, filters, annual service |
| Runtime | 8–48 hours (battery size dependent) | Unlimited (with fuel) |
| Whole-home backup | Requires 2–3 batteries | Standard |
| Cost (installed) | $12,000–$35,000 | $5,000–$15,000 |
| Operating cost | $0 (with solar) | $3–$8/hour of fuel |
| Federal tax credit | 30% ITC eligible | Not eligible |
| Works in garage/indoors | Yes | No (CO risk) |
Bottom line: Batteries are better for frequent short outages (< 24 hours), TOU optimization, and solar integration. Generators are better for extended multi-day outages in areas without solar resources. Many homeowners install both — a battery for instant switchover and daily optimization, plus a smaller generator for extended events.
How to Choose the Right Battery for Your Home
Consider these decision factors:
Backup goals: Essential circuits only → 1 battery. Whole home with AC → 2+ batteries or high-output unit (Powerwall 3, Franklin WH).
Solar integration: Already have Enphase microinverters → Enphase IQ 5P for seamless integration. New solar + battery → Tesla Powerwall 3 (built-in inverter saves $2,000–$3,000).
Budget: Under $10,000 installed → Enphase IQ 5P (single unit) or SolarEdge. $12,000–$15,000 → Powerwall 3 or Franklin WH. $15,000+ → Multi-battery system or Sonnen premium.
Climate: Hot climates → prioritize LFP chemistry and outdoor-rated units. Cold climates → ensure the battery's operating range extends below your minimum winter temperature (most go down to -4°F to -13°F).
Key Takeaways
- A single 13.5 kWh battery (Tesla Powerwall 3, Franklin WH) covers essential backup for 1–2 days without solar
- Pair with solar for indefinite backup capability and 7–10 year payback through TOU arbitrage
- The 30% federal tax credit now applies to standalone batteries (no solar required) through 2032
- For central AC backup, you need at least 10 kW peak output — Powerwall 3 and Franklin WH qualify; most Enphase/Sonnen single-unit configs don't
- LFP chemistry is winning — longer cycle life, better safety, lower long-term cost
- VPP programs can offset 15–30% of your battery investment over its lifetime
- Batteries and generators complement each other — batteries for instant/daily use, generators for extended outages
Frequently Asked Questions
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