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Blog | September 2021

How to buy home solar batteries

Home solar batteries can give you greater independence from the electricity grid than rooftop solar alone. A battery stores power generated by your solar panels to use when the sun goes down or on overcast days.

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Content Manager

Home solar batteries can give you greater independence from the electricity grid than rooftop solar alone. A battery stores power generated by your solar panels to use when the sun goes down or on overcast days.

But there's a lot of information on batteries out there, and it can all get a bit baffling! To make it easier to choose one, we’ve put together this guide to the basics of home solar batteries.

Some solar battery terminology

Here are a few of the terms you are likely to come across when researching home batteries to buy:

  • Storage size/capacity – refers to how much energy the battery can store, measured in kilowatt hours (kWh).
  • Power output – how much power (in kWh) the battery can deliver.
  • Depth of discharge – the relationship between how much the battery can store and how much it can deliver.
  • Cycles – a ‘cycle’ refers to one round of charging and discharging of the battery completely. While this process causes the battery to degrade over time, modern solar batteries should last many thousands of cycles.
  • Operating temperature range – this is the temperature range batteries need to function within. Batteries tend to be temperature sensitive and may stop functioning at very high or low temperatures.

Types of home solar batteries

The most common battery on the market today is the lithium-ion battery. Lithium batteries generally have good longevity (e.g. several thousand cycles) and can operate within a wide range of temperatures.

There are a few types of lithium-ion batteries available. One example is the lithium-ion phosphate or LFP battery. sonnen’s home batteries are entirely LFP since its very beginning in 2010.

5 factors to consider when buying a home battery

There are some key things to look at when buying the best solar batteries for your requirements.

  • Size – the size you need depends on several factors, such as how much grid independence you want, the size of your solar panel array, your household usage, your budget, and whether you are home during the day.
  • Lifespan – look for a battery with good longevity. With normal use and temperatures, a solar battery should last at least 10 years.
  • How much you could save – with solar panels and a home battery you could potentially save a lot on your electricity bills. But it’s important to have an idea of how much before you invest in one. sonnen has created a handy tool to help you work out what savings you could potentially achieve.
  • Customer support and warranties – it's not just about the solar battery price. Look at the warranty that comes with the battery and the level of customer support the company offers post-installation.
  • Government assistance – check to see if your state or territory government offers subsidies or interest-free loans you might be eligible for.

The sonnen advantage

If it’s a total solar energy solution you are looking for, sonnenBatterie is scalable and comes with the option of two innovative energy offers.

Here are some of the features:

  • Multi-stage storage system up to 15kWh that can be built up in blocks of 2.5kWh. This means you can start small and build your energy storage system over time, according to your needs and budget.
  • 10-year warranties (or 10,000 cycles).
  • Inbuilt AC/DC inverter, intelligent energy management system, usage measurement technology, and predictive charging.
  • Ability to work during a blackout with sonnenProtect (not all home battery brands are capable of operating during outages).
  • Peak efficiency of 98%.
  • Cobolt free LFP technology which contains zero heavy metals.
  • Smart energy management software – energy at your fingertips, monitor and track your usage in real-time.
  • Designed and made in Germany
  • You can choose an energy plan to help manage costs, such as the sonnenFlat monthly fixed fee plan, or sonnenConnect which allows customers to stay with their existing energy retailer and receive a daily reward to support the grid.

We hope our basic guide has made it easier for you to make your decision about buying a home solar battery.

Get in touch with our team if you would like to know more, or take our free online energy savings calculator here to see the estimated savings you could make over 10 years.