Home batteries
Home batteries explained
Battery quotes use terms that aren't always obvious. Here's what they mean.
Key terms
Usable capacity (kWh)
How much energy you can actually draw from the battery. Compare this figure, not the total or 'nominal' size.
Power (kW)
How much the battery can deliver at once — which affects how many appliances it can run together.
Backup
The ability to keep some or all circuits powered in a grid outage. Needs specific equipment and wiring.
Coupling
DC-coupled batteries share a hybrid inverter with solar; AC-coupled batteries have their own inverter and are common for adding to existing systems.
Sizing a battery
A battery is typically sized around your evening and overnight usage and how much excess solar you have to charge it. A larger battery isn't always better if it can't be filled regularly.
If you're thinking about an electric vehicle, pool pump or heat pump in future, mention it — it can change the recommendation.
Frequently asked questions
Do I need solar to get a battery?
Most home batteries are paired with solar so they can store daytime solar energy for use at night. Some batteries can also charge from the grid. Installers can explain what suits your situation.
Will a battery keep my power on during a blackout?
Only if the system is designed and installed for backup. Not every battery setup provides backup power, so ask each installer specifically what will and won't run during an outage.
Can a battery be added to my existing solar system?
Often, yes. Depending on your current inverter, you may need a hybrid inverter or a battery with its own inverter (AC-coupled). Tell us about your existing system and installers will advise.