Savant Power Storage 20 vs FranklinWH aPower 2
A straight, side by side read on specs and warranties, with the honest caveats. Every figure is from the manufacturer datasheet; sources are at the bottom.
| Spec | Savant Power Storage 20 | FranklinWH aPower 2 |
|---|---|---|
| Chemistry | LiFePO4 | LFP |
| Usable capacity | 18 kWh | 15 kWh |
| Continuous power | 12.5 kW | 10 kW |
| Peak power | 30 kW | 15 kW |
| Round-trip efficiency | 93.8% | 90% |
| Warranty | 10 years, warrantied to 73 MWh or 3,650 cycles, with an estimated 75 percent capacity retention at 10 years | 15 years or 60 MWh throughput, whichever comes first |
| Backup scope | Whole-home capable | Whole-home capable |
| Inverter | Integrated | Integrated |
What actually differs
- More usable capacity: the Savant Power Storage 20 offers 18 kWh vs 15 kWh, so at that size it carries more of your home for longer per charge.
- More continuous power: the Savant Power Storage 20 sustains 12.5 kW vs 10 kW, which matters for running big loads like an AC at once.
- Longer warranty term: the FranklinWH aPower 2 is warranted 15 years vs 10, though always read the throughput or cycle cap too.
- Different chemistry: the Savant Power Storage 20 is LiFePO4 and the FranklinWH aPower 2 is LFP. For a battery that never moves, LFP's safety and cycle life usually beat NMC's higher energy density.
- Efficiency is not apples to apples here: the Savant Power Storage 20 quotes 93.8% (Round trip efficiency per the Savant Power Storage 20 specification sheet) and the FranklinWH aPower 2 quotes 90% (grid to battery to load (AC round trip)), so do not read the raw numbers as a direct ranking.
Which one pays off is a numbers question.
Neither spec sheet tells you the payback in your home. That comes from your rate plan and incentives.
Run the Worth It calculator →Power Storage 20 vs aPower 2 FAQ
Is the Savant Power Storage 20 or the FranklinWH aPower 2 better?
Neither is universally better. The Savant Power Storage 20 carries more usable capacity (18 kWh vs 15 kWh), while the smaller unit can cost less and fit tighter spaces. The right pick depends on your home's loads, backup needs, and budget, not the brand on the box.
What is the difference in usable capacity between the Savant Power Storage 20 and the FranklinWH aPower 2?
The Savant Power Storage 20 offers 18 kWh and the FranklinWH aPower 2 offers 15 kWh of usable capacity.
Which has more continuous power, the Savant Power Storage 20 or the FranklinWH aPower 2?
The Savant Power Storage 20 sustains 12.5 kW continuous vs 10 kW, which matters for running big loads like an air conditioner at once.
Which has the longer warranty, the Savant Power Storage 20 or the FranklinWH aPower 2?
The FranklinWH aPower 2 is warranted 15 years vs 10 for the Savant Power Storage 20. Read the throughput or cycle cap too, since that can limit coverage before the year count does.
Is the Savant Power Storage 20 or the FranklinWH aPower 2 cheaper?
Neither spec sheet tells you the installed cost or the payback in your home. That depends on your electricity rate plan and local incentives, so run the numbers for your address rather than comparing sticker prices.
Sources
Source: Savant Power Storage 20 Specification Sheet (009-2477-00). Specs verified 2026-07-01. Figures are per single unit at beginning of life; confirm the current datasheet with your installer.
Source: FranklinWH aPower 2 datasheet, Dec 2025. Specs verified 2026-07-01. Figures are per single unit at beginning of life; confirm the current datasheet with your installer.