What type of home battery should I install?

There are a few types of batteries on the market, including lithium-ion, lead acid, and flow batteries, each with its own pros and cons.

Lithium-ion

Lithium-ion batteries have emerged as the go-to choice for home energy storage. They're popular for household applications on account of their high energy density, allowing a large amount of electricity to be stored in a compact and lightweight package.

Unlike other battery technologies, lithium-ion cells are highly flexible, and able to be discharged regularly to 80 or 90 % of their capacity - and beyond - without impacting long-term performance.

The first commercial lithium-ion batteries became available in the mid-1980s and can today be found in mobile phones, laptops and electric vehicles. Lithium-ion is well-established as a battery technology and is evolving quickly, driven by innovations in electric vehicles and as a way of storing renewable energy at a domestic and grid scale.

Lead acid

Lead acid batteries are a tried and tested option that has been popular in large off-grid applications.

The technology has existed for more than 100 years, so is well understood, but offers a lower energy density than lithium-ion alternatives. Generally, a lead acid battery would be four times heavier than a lithium-ion system to achieve the same amount of energy storage.

The cycle life of lead-acid batteries also falls away sharply if they are discharged beyond 30 - 40% of their capacity regularly, so care is required. If cycle life and temperature are managed, lead acid batteries commonly can last for upward of 10 - 15 years.

Flow batteries

Describing a number of different variants, flow batteries store energy in a liquid electrolyte solution. They offer strengths over other technologies, in that they're able to be regularly discharged to 100% of their capacity without impacting lifespan and are able to withstand extreme temperatures.

Their disadvantages are their comparatively large size compared to lithium-ion and lead acid batteries, and higher price tag.