Powerwall vs Enphase vs FranklinWH: A California Battery Comparison (2026)

Capacity (kWh) is the size of the tank — how much energy the battery stores and can deliver before it needs recharging. It sets how long you can run your loads. Continuous power (kW) is the size of the pipe — how much the battery can deliver at any one instant. It sets how much you can run at once (an AC compressor, an electric range, a well pump).

One caution when comparing capacity numbers: manufacturers define capacity differently — nominal energy, usable energy, or AC energy measured under specific test conditions are not the same figure. Don't assume two "kWh" numbers were measured the same way; use the exact capacity definition stated in the current datasheet and warranty for the specific model you're quoted.

A big tank with a small pipe can run a few lights and a fridge for a long time but will trip if you start a heat pump. A big pipe with a small tank can start heavy loads but drains fast. For whole-home backup you want both; for overnight bill-shifting under NEM 3.0, capacity usually matters more than peak power. Our home battery sizing calculator walks through how many kWh your specific loads need.

Solar panels produce DC power; your home uses AC. A DC-coupled approach captures panel energy on the DC side before it's converted, which is efficient and tidy for a new solar-plus-storage install. The Powerwall 3 fits here: it integrates a solar inverter and takes direct DC solar input (up to ~20 kW DC), so one box handles inverting and storage — and, depending on the approved configuration, it may also be used with AC-coupled solar. An AC-coupled battery (Enphase IQ, FranklinWH aPower 2) has its own inverter and connects on the AC side, which makes it straightforward to add onto an existing solar system without replacing your current inverter or microinverters.

Neither approach is universally better. If you already run Enphase microinverters, an Enphase battery is the most seamless match. If you're installing fresh solar and want backup in one unit, a Powerwall 3 with direct DC solar input can simplify the design. FranklinWH's AC-coupled aGate is built to orchestrate solar, battery, grid and even a backup generator together, which suits larger or more complex homes. The right answer falls out of your existing equipment, not a brand ranking.

A battery warranty usually promises a minimum capacity retention (for example, that it will still hold at least 70% of its original kWh at the end of the term) and sometimes a throughput or cycle limit — whichever comes first. Tesla warrants the Powerwall 3 for 10 years at ≥70% retention. Enphase covers the IQ Battery 5P and 10C for 15 years (up to roughly 6,000 cycles). FranklinWH backs the aPower 2 for 15 years or 60 MWh of throughput per unit at 70% retention, whichever comes first.

Two "15-year" warranties aren't identical: a cycle or throughput cap can matter if you cycle the battery hard every day. Ask what's guaranteed at end of term, whether labor and the inverter are covered, and who honors the claim — the manufacturer or your installer. A warranty is only as good as the company standing behind it a decade from now.

Honestly: it depends, and any installer who names a "best battery" before seeing your roof and your goals is skipping steps. As a neutral rule of thumb from what we install across Los Angeles — a Powerwall 3 pairs cleanly with new solar and delivers strong whole-home backup in one DC-coupled unit; the Enphase IQ line shines on existing microinverter systems and when you want to size storage in small, modular steps; the FranklinWH aPower 2 suits larger homes, heavier loads, and setups that need generator integration. All three carry legitimate multi-year warranties (Enphase and FranklinWH specify LFP chemistry; check Tesla's current Powerwall 3 datasheet for its chemistry disclosure). The deciding factors are your existing equipment, your backup vs savings priority, and your budget — not brand loyalty. We install all three, so we'll size and quote whichever genuinely fits your home.

Want to work out the numbers for your house first? Start with the battery sizing calculator, then talk to us at +1-323-844-7777.