Solar Batteries Explained

Capacity is the number that misleads

Nominal capacity is what is printed on the box. Usable capacity is what you can actually draw. Compare usable figures or you are not comparing like with like.

Chemistry

Lithium iron phosphate dominates the domestic market now. It is chosen for cycle life and thermal stability rather than for energy density, which matters far less in a garage than it does in a car.

Hybrid or AC-coupled

Hybrid combines solar and battery in one inverter and is the tidier answer on a new build. AC-coupled adds a separate battery inverter and is the usual retrofit route. Neither is universally better.

Backup

Backup during a power cut is a design decision, not a standard feature. It needs a supported product and extra wiring, and it usually powers selected circuits rather than the whole house.

Warranties

Battery warranties are commonly written as around ten years or a stated number of cycles or a total energy throughput, whichever comes first — and they usually guarantee retained capacity rather than simply function. Read which of those applies before comparing two quotes.