How Do Solar Batteries Work

The goal is simple. Store excess solar power for use later when it would have otherwise been sent to grid and paid as a Feed-In-Tariff.

Solar feed-in-tariffs have been on the decline due to the increasing up-take of solar on many homes and businesses. On the contrary, energy prices have significantly increased during the evening when the grid is short on supply. This has meant that energy storage via solar batteries has become more attractive than ever. Homes need stored power during the peak demand times when power prices are at their maximum.

Solar batteries have seen significant development and improvement over the past 5 years. Both size and battery chemistry have seen significant improvements while cost has remained relatively flat. This has meant that the value proposition of a battery has improved dramatically as they can do a lot more now and are safer than ever.

The two most popular brands in the battery market are Tesla Powerwall II and Sungrow HV Batteries.

When do you need a hybrid inverter?

Some batteries known as AC Coupled batteries come with their inverter built into the battery. This means you don't need a separate Hybrid inverter to handle the charge and discharge function of the battery. Tesla is an example of an AC Coupled battery.

Sungrow on the other hand is a DC Coupled Battery. This means that a Hybrid Inverter is required to act as the brains of the unit. This can be handy because the Hybrid allows us to connect solar panels as well. This results in a more efficient charging process and can also save costs as it may mean you don't need a normal inverter to connect the solar.

Modular Batteries

Sungrow HV Battery is a modular battery that is stacked in 3.2kWh modules. This provides a distinct advantage over other batteries as the cost to upgrade or adjust the size is less significant than conventional batteries like the Tesla Powerwall II.

One of the advantages of working with a team like us at Virtual Power Co is that we can expertly guide you on when to upgrade and add more modules based on your monitoring data.

Blackout / UPS

Any good battery can provide an emergency power supply, or blackout protection as it's more commonly known. This works quite simply for normal single phase homes. When the power goes out, the inverter connected to the battery (or inside the battery in the case of the Tesla) will sense that the grid connection has failed. This will then result in an automatic changeover to the battery in a split second, returning full power to the home. (This function is limited to the SH10.0RS Hybrid Inverter which we will recommend if you require full home backup).

On three phase homes, there is currently no battery that can provide full three-phase backup. It should be noted that it will almost never be possible to provide a backup solution capable of spinning a three phase motor (such as a 3 phase air conditioner) as no hybrid inverter or battery solution presently can generate the phase difference required to spin the motor.

Sungrow has shown a new generation of three phase hybrid inverters that will be capable of providing backup to all single phase circuit breakers that are split across all three phases. This is in essence almost equivalent to full home back-up and likely the closest we will get to a working solution. We expect this solution to be available in late Q2 2024. If you are confused by this, don't worry, it is quite technical. You may benefit from requesting an in-home consultation with one of our consultants who can explain this in detail for your situation.


Tesla and Sungrow both provide 10 year warranties on their products.

Tesla's warranty covers up to 30% degradation over a ten-year period or up to 3600 cycles in total (which covers almost one full cycle per day).

Sungrow covers up to the minimum of 40% degradation over a ten-year period or a minimum throughput energy which is often 1.14x the batteries original capacity discharged once per day over ten years.

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