Get the facts, not the hype.
A side-by-side built to run the full 22-year lifecycle, including the major costs and assumptions.
Figures are nominal and use the assumptions shown below.
A battery’s upfront purchase price is only part of the comparison. The model also allows for relevant replacement costs, inverter life, battery capacity assumptions, cleaning, rebates, tariffs and supply charges over the full comparison period.
Every major assumption is visible and editable below.
Warranties guarantee a floor, not a cliff-edge: most 2026 home batteries promise 60–80% of original capacity at the 10-year mark, and real LFP cells often do better. This chart is deliberately conservative and uses the warranty floor, resetting at each replacement.
Cumulative net position each year: total spend so far (system, STCs/rebates, cleaning, replacements) subtracted from cumulative bill savings.