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NuWatt designs, installs, and manages solar, battery, heat pump, and EV charger systems across 9 states. One company, one warranty, one point of contact.
Get a Free QuoteThree batteries NuWatt actively installs across the Northeast and Texas. Same LFP chemistry, same general size class — very different jobs. We picked these for whole-home backup, Enphase ecosystem matching, and generator integration respectively. Honest head-to-head from an installer that puts all three on roofs every week.
Pick the one that matches your use case. Powerwall 3 (13.5 kWh, 11.5 kW continuous) is the choice when you need whole-home backup including central AC and the highest ConnectedSolutions VPP earnings. Enphase IQ 10C (10 kWh, 7.08 kW, 15-year warranty) is the choice when you already run Enphase microinverters or want the longest warranty for the price. FranklinWH aPower 2 (15 kWh, 10 kW, IP67 outdoor-rated) is the choice when you need the most single-unit capacity, generator integration, or a coastal/outdoor install. All three are LFP chemistry — none have the thermal-runaway risk of older NMC batteries.
All three are LFP (same fundamental chemistry safety profile). The trade-offs are between capacity, continuous power, warranty term, and price.
Capacity
13.5kWh
Continuous
11.5kW
Peak
22 kW
Warranty
10 yr
Installed price (NuWatt)
$14,000–$16,500
≈ $1130/kWh installed
Capacity
10kWh
Continuous
7.08kW
Peak
10.5 kW
Warranty
15 yr
Installed price (NuWatt)
$12,000–$14,500
≈ $1325/kWh installed
Capacity
15kWh
Continuous
10kW
Peak
15 kW
Warranty
15 yr
Installed price (NuWatt)
$16,000–$19,000
≈ $1167/kWh installed
The honest answer to “which is best” depends on what you need the battery to do. Match your top-priority scenario below to the recommended battery.
Whole-home backup including central AC
Powerwall 3 starts motors up to 185 LRA — the only single-unit battery that reliably handles a 3-ton+ central AC compressor inrush without throttling.
You already have (or plan) Enphase microinverters
IQ 10C is AC-coupled and slots cleanly into the Enphase ecosystem (same monitoring app, same installer toolchain, same IQ Combiner). Avoids dual-vendor complexity.
Highest single-unit capacity / heavy loads / off-grid
15 kWh in one box, 10 kW continuous, IP67 (install outdoors), and the aGate controller integrates a backup generator natively. Best for true whole-home + extended-outage planning.
Longest warranty + highest cycle count
IQ 10C and aPower 2 both carry 15-year / 6,000-cycle warranties. The IQ 10C is the lower-cost path to that warranty tier; aPower 2 is best when you need the extra capacity.
Maximum ConnectedSolutions VPP revenue
11.5 kW continuous dispatch is the highest of any residential battery. On Eversource MA at $275/kW summer, a single Powerwall 3 earns roughly $3,160/yr summer + $570 winter ≈ $3,730 first-year potential before any solar self-consumption stacking.
Coastal / damp / outdoor install constraint
aPower 2 is IP67 rated — the only one of the three that is fully sealed for outdoor exposure. Powerwall 3 and IQ 10C are weather-resistant but prefer covered/garage installs in the Northeast.
Every spec a NuWatt designer pulls when sizing your system. Mobile-friendly horizontal scroll if your screen is tight.
| Spec | Powerwall 3 | IQ 10C | aPower 2 |
|---|---|---|---|
| Usable capacity | 13.5 kWh | 10 kWh | 15 kWh |
| Continuous output | 11.5 kW | 7.08 kW | 10 kW |
| Peak output (10 s) | 22 kW | 10.5 kW | 15 kW |
| Round-trip efficiency | 97% | 96% | 95% |
| Chemistry | LFP | LFP | LFP |
| Warranty | 10 yr / 5,000 cycles | 15 yr / 6,000 cycles | 15 yr / 6,000 cycles |
| Coupling | Hybrid (AC+DC) | AC-coupled | Hybrid (AC+DC) |
| Weight | 225 lb | 187 lb | 249 lb |
| Installed price (NuWatt) | $14,000–$16,500 | $12,000–$14,500 | $16,000–$19,000 |
| ≈ Price per usable kWh | $1037–$1222/kWh | $1200–$1450/kWh | $1067–$1267/kWh |
| Manufactured in | Lathrop, CA | USA (multi-site) | CA (assembly) |
ConnectedSolutions pays based on continuous kW dispatch — not kWh capacity. So the higher-power Powerwall 3 earns more per battery than the larger-capacity aPower 2. Numbers below use the Mass Save published rate of $275/kW annual (Eversource and National Grid identical), as of 2026.
Powerwall 3
$3,163
per year (11.5 kW × $275)
10-year potential
$31,630
IQ 10C
$1,947
per year (7.08 kW × $275)
10-year potential
$19,470
aPower 2
$2,750
per year (10 kW × $275)
10-year potential
$27,500
Stacking: ConnectedSolutions revenue is additive to your solar self-consumption savings (typically $400–$800/yr) and to time-of-use arbitrage ($200–$500/yr where TOU rates apply). It does not conflict with SMART 3.0 storage adders on the solar side of the system. See our ConnectedSolutions VPP guide for the full stacking math.
All three are LFP and engineered for daily cycling. Warranty terms are where the real differentiation lives.
Tesla Powerwall 3
10 years / 5,000 cycles
Standard Tesla 10-year warranty. Cycle count is enough for daily cycling for ~13 years before warranty cycle cap. Tesla's service network is the most established of the three.
Enphase IQ 10C
15 years / 6,000 cycles
The longest warranty term of the three. 6,000 cycles is roughly 16 years of daily cycling. Best warranty-per-dollar in this comparison.
FranklinWH aPower 2
15 years / 6,000 cycles
Same warranty tier as IQ 10C. Franklin is a newer brand than Tesla or Enphase — the 15-year warranty is the company's confidence signal about long-term reliability.
For a typical 2,000–3,000 sq ft Northeast home with central AC, Powerwall 3 is what we recommend by default. The 11.5 kW continuous + 22 kW peak output is the only single-unit battery that reliably starts a 3-ton+ AC compressor without throttling, and the ConnectedSolutions revenue per battery is the highest of the three. The 10-year warranty is shorter than the alternatives but Tesla's service track record makes it a non-issue in practice.
Two situations: (1) you already run Enphase microinverters — staying in-ecosystem avoids dual-monitoring complexity and saves $400–$800 on integration labor. (2) Warranty length matters to you specifically — the 15-year / 6,000-cycle term beats Powerwall 3 by 50% on cycles. Plan for two units (20 kWh total) if you need whole-home backup including AC.
Three situations: (1) you need 15 kWh in a single unit (rare for one battery, common for stacks). (2) You have a backup generator already — the aGate's native generator integration is best in class. (3) You need IP67 outdoor mounting (coastal install, no garage, lakeside cabin).
Single-product review
Tesla Powerwall 3 — full review
Deep dive on the 11.5 kW continuous + 22 kW peak output, Storm Watch behavior, and install caveats.
Single-product review
Enphase IQ Battery 10C — full review
15-year warranty math, IQ Combiner integration, and why the 10C usually beats stacking five 5Ps on cost.
Single-product review
FranklinWH aPower 2 — full review
aGate generator integration, IP67 outdoor install cases, and the 225 kWh max-stack ceiling.
Master guide
Best home battery 2026 — all picks
Full ranking across all battery classes including modular IQ 5P, smaller backup batteries, and our non-picks (Generac, LG).
Revenue stacking
ConnectedSolutions VPP — Massachusetts
How the $275/kW figure works, who pays it, and how to enroll. 227 MW of MA capacity is already on the program.
Get an installed quote
Configure your system — instant quote
Pick panels, inverter, and one of these three batteries. Real installed pricing in your zip in ~2 minutes.
