Thinking about solar battery storage? Here's what to keep in mind | Infinite Energy

Thinking about solar battery storage? Here’s what to keep in mind

Thinking about solar battery storage? Here's what to keep in mind

Written by Infinite Energy

If you have solar panels on your roof, it’s likely you have considered investing in solar battery storage, after all, there is an obvious benefit to storing your unused electricity to use at night rather than exporting to the grid. In this blog, we’ll discuss what to look out for if you decide to add a solar battery to your solar power system.

How does solar battery storage work?

Battery storage allows you to store your unused solar electricity in a battery for later use, rather than sending it back to the grid for a feed-in tariff. The stored solar power can then be used at night when your system isn’t generating electricity, which is generally the time when most people are consuming the most energy. Certain batteries can even continue to supply power to your home in the event of a blackout, so you can keep your essential appliances like fridges and lights running.

What do you need to consider when shopping for solar batteries?

When considering investing in a solar battery to use for energy storage, it is important to compare apples with apples. Some of the best ways to ensure you are comparing batteries correctly is to consider and compare the following:

  • Battery life and warranty
    A battery’s lifespan is roughly somewhere from five to 15 years, depending on what solar battery brand you invest in. Warranties for batteries are generally stated in years or cycles, which refers to the cycle of the battery charging and discharging. For example, the sonnenBatterie has a warranty of 10 years or 10,000 cycles (whichever comes first).
  • Power capacity
    The power capacity of the solar battery refers to the total amount of electricity that the battery can hold. Solar batteries are usually stackable, meaning you can have multiple battery storages at home to increase their capacity. An example of this is the BYD battery Box Premium which can be increased in storage capacity in increments of 2.8 kWh, taking the battery to a maximum of 22.1 kWh capacity, plus the battery can have 3 maximum-capacity BYD batteries connected together, creating an incredible 65.1 kWh of battery storage.
  • Depth of discharge (DoD)
    The depth of discharge, or DoD, measures the degree to which a battery can be used relative to its total capacity. If a battery has a 100% DoD it means you can use the full battery storage amount to power your home. If a battery has a 94% DoD, it means you can use up to 94% of the battery capacity, for example, for a 2.5kWh battery, you can use down to 2.35kWh before the battery needs to charge again.
  • Your power requirements
    Generally, most Australian households use up to 20kW per day, depending on their household size and their energy requirements. Most people would use at least 10 units at night for their consumption for things like lights, fridge, TV and cooking appliances. This doesn’t factor in additional power-hungry appliances as well, such as reverse-cycle heating and air-conditioning. You will need to ensure that the battery you invest in will be large enough to accommodate your energy needs overnight with your stored solar energy to reduce your reliance on more expensive, grid-supplied energy
  • Price per kilowatt hour
    If you come across a suspiciously cheap price on a solar battery, it is well worth looking into the price per kilowatt hour. Solar batteries can often be priced more competitively when it they are of smaller size. To get a better idea of the true cost divide the price by size of the battery to find out what the price per kilowatt hour will be.
  • Other considerations
    It is also important to investigate how long the battery manufacturer has been in the market, particularly if they are a brand that you have not heard of before. Also consider whether the brand has an Australian presence or local offices which is important when it comes to dealing with service, repairs and warranties.

Why are some solar batteries cheaper than others?

There has been a big marketing push for batteries recently, with some companies promoting solar batteries for as little as $4,000, which is obviously quite a deal. But as the old saying goes, if it sounds too good to be true, it normally is! As an example, we have compared two popular solar batteries using the considerations above.


Tesla Powerwall 2


Battery life

10 years/ “unlimited cycles”

5 years/ 6,000 cycles

Power Capacity




96.4% 13.5kWh

96% (2.8kW)

Hours of standard electricity coverage

6 hours (usage @2kW/hour)

1.5 hours (usage @2kW/hour)

Sale price



Price per kWh




As you can see from the above, while the price of the Tesla Powerwall 2 might be more upfront, the cost per kWh means it actually works out to be more efficient to use than the much cheaper HIVE battery, will supply your home with more energy overnight and will last a lot longer based off the battery life and warranty conditions, which ultimately saves you significantly more money in the long run.

Investing in solar battery storage for your solar power system is a big investment, and one that should be considered carefully, we hope the information we have provided will help you to consider your options with more confidence. If you would like further information on whether battery storage is suitable for your situation, get in touch with us by arranging a call-back, or give us a call on 1300 074 669.

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