2026 Battery Comparison
Tesla vs. Sigenergy vs. FranklinWH vs. Enphase
A side-by-side comparison of the four home battery systems we install most often in Southeastern Pennsylvania — with specs, capabilities, and our honest take on who each one is best for.
| Feature | Tesla Powerwall 3 | Sigenergy SigenStor | FranklinWH aPower 2 | Enphase IQ Battery |
|---|---|---|---|---|
| Usable capacity (per unit) | 13.5 kWh | 5.84 kWh / 8.76 kWh modules | 15 kWh | 5 kWh (5P) / 10 kWh (10C) |
| Maximum stack capacity | 54 kWh (4 units) | 48+ kWh per stack | 225 kWh (15 units) | Modular, no hard cap |
| Continuous power output | 11.5 kW | 11.5 kW | 10 kW (15 kW peak) | 3.84 kW (5P) / 7.08 kW (10C) |
| Battery chemistry | LFP (lithium iron phosphate) | LFP | LFP | LFP |
Why it matters: All four use LFP — the safest chemistry for residential use, with minimal fire risk vs. NMC. | ||||
| Integrated solar inverter | Yes, 6 MPPT | Yes, 4 MPPT | AC-coupled (separate) | Uses microinverters |
| Whole-home backup capable | Yes | Yes | Yes (with aGate) | Yes (min 20 kWh + System Controller) |
| Bidirectional EV charging (V2X / V2H) | Cybertruck only (Powershare) | Yes (V2H/V2X) | No | No |
| Generator integration | No | Yes (built-in) | Optional module | Coming soon |
Why it matters: Generator integration matters in rural areas with extended outages — you can charge the battery from a generator when solar can't keep up. | ||||
| AI / smart energy optimization | Cloud-based | Onboard AI + Smart Circuits | Smart Circuits | Cloud-based |
| Manufacturer warranty | 10 years | 10 years | 15 years / 60 MWh | 15 years |
| Mobile app | Tesla app | mySigen | FranklinWH app | Enphase Enlighten |
| Indoor / outdoor rating | Indoor + outdoor | Indoor + outdoor | Indoor + outdoor | Indoor + outdoor |
Specifications based on publicly available manufacturer data as of 2026. Verify current specs at the time of purchase.
Our take: who each battery is best for
Tesla Powerwall 3
Best for: Great bang for your buck. DC-coupled with an integrated 6-MPPT solar inverter means fewer components and a clean, polished install.
- DC-coupled = better efficiency and lower installed cost vs. AC-coupled alternatives
- Integrated 20 kW solar inverter with 6 MPPTs — fewer components
- Best-in-class app and seamless backup transitions
- V2X limited to Cybertruck only (Powershare)
- Fixed 13.5 kWh size — must buy whole units to expand
Sigenergy SigenStor
Best for: The price leader for DC-coupled systems, with the best modularity and lowest future expansion costs. Also the only system here with true V2X bidirectional EV charging.
- DC-coupled and typically the lowest cost per kWh installed
- Highly modular — 5.84 and 8.76 kWh modules, stackable to 48+ kWh, with inexpensive add-on cost
- Only system here with true V2X / V2H capability
- Onboard AI handles time-of-use arbitrage automatically
- Newer to the US market than Tesla / Enphase
- Smaller installer network — make sure your installer is certified
FranklinWH aPower 2
Best for: A strong AC-coupled retrofit option — ideal for adding battery storage to an existing solar system without replacing your current inverter.
- AC-coupled = works with virtually any existing solar inverter
- Largest scalable capacity (up to 225 kWh)
- Optional generator integration module
- Best warranty among AC-coupled systems (15 years / 60 MWh)
- AC-coupled = slightly lower round-trip efficiency than DC-coupled systems
- No V2X capability
Enphase IQ Battery
Best for: The natural choice if you already have Enphase microinverters — same app, same monitoring, seamless integration. Also a good AC-coupled retrofit option.
- Native integration with existing Enphase microinverter solar systems
- 15-year warranty — industry leading
- 5 kWh modules are the smallest building blocks here
- Lower per-unit power output than competitors
- Whole-home backup requires minimum 20 kWh of batteries + System Controller
- No V2X capability
How to actually pick one
The honest truth: any of these four batteries will keep your lights on in an outage and pair fine with PECO's 1:1 net metering. The differences come down to four questions:
- 1New solar + battery install? Go DC-coupled. Sigenergy is the price leader with the best modularity and the lowest future expansion costs. Tesla Powerwall 3 is also excellent — polished, proven, and great value with its integrated 6-MPPT inverter.
- 2Already have Enphase microinverters? Enphase IQ Batteries are the natural add-on — same app, same monitoring, native integration, plus a 15-year warranty. No new inverter needed.
- 3Adding battery to an existing non-Enphase solar system? FranklinWH aPower 2 is a strong AC-coupled retrofit — it works with virtually any existing inverter and scales to 225 kWh if you have a large home.
- 4Do you (or will you) own a compatible EV? Sigenergy's V2X is the only system here with true bidirectional charging — your car becomes a 60–100 kWh whole-home battery that also drives.
Frequently asked questions
What does a home battery cost installed in Southeastern PA?+
Installed pricing starts around $15,000 and varies depending on the battery system, storage capacity, electrical panel requirements, and site conditions. Every home is different, so the best way to get an accurate number is to request a free consultation — we'll walk through your specific setup and provide an itemized quote.
Do all four work with PECO's 1:1 net metering?+
Yes. All four are grid-tied capable and fully compatible with PECO net metering. The battery determines what happens during outages and time-of-use arbitrage — net metering is a separate function of the inverter and your interconnection agreement.
Which has the best warranty?+
FranklinWH and Enphase both offer 15-year warranties — FranklinWH's includes a 60 MWh throughput guarantee, which accounts for actual cycling. Tesla and Sigenergy are both 10 years. All four warranty 70%+ usable capacity at end of term.
Can I mix and match — say, Tesla solar with a Sigenergy battery?+
Generally no. Each manufacturer's battery talks to its own inverter and gateway. AC-coupling FranklinWH or Enphase to a different brand's solar inverter is possible; coupling Tesla Powerwall 3 or Sigenergy SigenStor to a third-party solar inverter is more limited because they're hybrid systems designed to manage the solar side themselves.
Are any of these eligible for incentives?+
Pennsylvania does not currently offer state-level battery rebates. The federal 30% residential clean energy credit ended December 31, 2025. New Jersey (Jersey Shore service area) has battery incentive programs — those vary by year. We confirm current eligibility during the consultation.
How long does battery backup last during an outage?+
Depends on capacity, your loads, and whether your solar is producing. As a rough rule: a 13.5 kWh battery powers a typical home for 12–24 hours of normal use, longer if loads are managed. With solar continuing to produce during the day, backup duration is effectively unlimited as long as the sun rises. Sigenergy + a compatible EV can extend backup to 2–4 days using the EV's 60–100 kWh battery.
Not sure which battery is right for your home?
We're certified installers for all four. We'll walk through your loads, backup goals, EV plans, and budget — and recommend the system that actually fits, not the one with the biggest marketing push.
Get a Battery Recommendation