What Size Solar Battery Do I Need for My Home?

At EcoFlow, we offer a range of solar solutions, such as the popular PowerOcean Home Battery, which allows for energy independence and a myriad of cost-saving benefits. Our team often gets asked, "What size solar battery do I need?" as needs can vary from property to property, and the choice you make matters.

You see, when you select the correct solar battery for your needs, it means you a) don't overspend on unnecessary capacity, b) maximise your energy efficiency, and c) ensure you have the right amount of storage to cater for your energy needs.

So, in this blog, we explain the various factors that go into answering that question and explain the solar battery size calculator UK consumers can use to determine the right option.

What do we mean when we ask - what size solar battery do I need? Are we talking about physical solar battery dimensions cm and inches? Well, that does also play a part in terms of installation, but the ‘size' aspect we're discussing has more to do with capacity, e.g. kWh (Kilowatt Hours) that it can provide on an ongoing basis.

Solar batteries come in a variety of sizes and types, so it can be tricky to understand which is right for your needs. However, your main aim is to ensure you have enough to cover your needs - and a little bit more. That's because you don't want to be at full capacity all the time, as it can lead to damage.

To avoid this damage during the battery selection process, you have to consider the usable battery, or Depth of Discharge (DoD), as it's otherwise known. Staying within these parameters - which typically comprise 90-95% of the battery's total capacity - will ensure maximum efficiency and extend the hardware's lifespan.

When considering the question, "What size solar battery do I need?" you'll see that they range from 1 kWh right up to 25 kWh. The higher the storage capacity, the more your system will cost you, but you'll be able to run your appliances for longer on a single charge.

Another term you should acquaint yourself with is Power Rating, which is an important number to watch out for. It indicates the maximum amount of power the battery can deliver at any particular time, again measured in kW. The reason this is important as it will determine how many appliances and home systems you’ll be able to run at the same time.

Conversely, battery capacity will determine how much time those appliances can run, so they’re effectively two sides of the same coin. When working out this figure, try and consider what will be used at peak times of the day. In the table below, you can get a good idea of how each appliance is rated in terms of running watts.

Essentially, you need to ensure that the power rating of the home battery you choose exceeds your maximum need at peak times, or you'll have to start choosing which appliances not to run.

Lastly, we have round-trip efficiency (RTE), which is basically a measure of how effectively the battery in question receives and stores energy. This is expressed as a percentage, and the closer it is to 100%, the lower the amount of energy that's lost during the process of charging and discharging.

For instance, when a home battery has an 85% RTE, it means that 85% of the energy stored will be returned for use. When deciding what size solar battery do I need for my home? you should be looking for options that have the highest possible number, as it will make it more cost-effective.

Several factors must be considered when choosing the right battery size for your home solar system. Let's examine each one.

The first point of consideration is the amount of energy that you typically need to run your home.
Generally speaking, an average UK family home uses around 9 kWh per day, meaning that a 10.8 kWh system would cover continuous power as needed and account for the DoD aspect described above.

If your home is small-to-medium in size and you, then a 3.6 kWh or a 7.2 kWh battery may meet your ongoing power requirements. However, if you want to be more specific about how much you use on a daily basis, there is a quick and easy way to do it.

If you're lucky enough to have a smart meter, you'll be able to get all the information, as well as track your usage in real-time.

Something else you need to think about when answering the question of what size solar battery do I need? is how much backup protection you want to have in place. Do you want to be protected against short grid power outages or for longer, which may necessitate the use of a larger battery capacity?

Should you be looking for something that would keep your home running for 24 hours, then you’re likely to need something with a 10 kWh capacity. If not, something smaller will suffice.

Another important element in the equation is the type of home battery you’re going to have fitted. There are lead-acid, saltwater, Nickel-Metal Hydride (NiMH), Nickel-Cadmium (NiCd) Batteries and Lithium Ion options to choose from.

Lithium Ion home batteries are known to be the most efficient, meaning that when choosing anything else, you might need a higher capacity.

'What size solar battery do I need for my home?' is a pertinent question when considering investing in a home battery setup, so you're right to ask it. As we can see, there’s no single answer, as it all depends on the type and size of home you have, the amount of energy you tend to use and the specific equipment that you’re having installed.

The good news is that the EcoFlow team is on hand to help you navigate what can be a minefield and find the perfect home battery solution for your needs. They’ll take the time to ask you a series of searching questions about what you’re looking for and recommend the ideal hardware for the job.

If you’re considering adding the benefits of a home solar system to your home and you’d like to know more, simply take a look at our website Homebattery.EcoFlow.com/uk. You’ll discover that it contains everything you need to know about the features and specifications of our industry-leading home battery solutions.

Alternatively, to chat about your needs with our team directly, just head to our homepage and click 'Order Now' to get a free quote tailored exactly to your needs.