What Size Home Battery Do I Need?
Choosing the right home battery size comes down to how much energy you use, when you use it, and what you want the battery to do — reduce bills, provide blackout backup, or both. Undersizing wastes the opportunity; oversizing wastes money.
Important Safety Warning
A battery installed without a compatible hybrid inverter won't provide blackout backup — it'll just go dead with the grid. Confirm your inverter specs before purchasing a battery.
Common Signs & Symptoms
- Solar panels generating more than you use during the day (excess exported to grid)
- High electricity bills despite having solar
- Interested in blackout protection for essential circuits
- Unsure whether 5kWh, 10kWh, or 13kWh+ is right for your home
Potential Causes
Why is this happening? Here are the most common reasons we see in WA homes:
- Most Perth households use 15–25kWh per day
- A 10kWh battery covers an average evening + night for a 3–4 person household
- Single-phase homes are limited to certain battery sizes without a switchboard upgrade
- Blackout backup requires a 'backup-capable' hybrid inverter, not just any battery
Troubleshooting Steps (DIY Safe)
- 1Find your average daily energy use on your electricity bill (look for kWh/day).
- 2Identify when you use most power: if it's evenings and nights, a 10kWh battery suits most homes.
- 3Decide if whole-home backup or just critical circuits (lights, fridge, phone charging) is the goal — this affects the inverter and wiring required.
- 4Get a solar/battery assessment from an accredited installer who can model your usage and suggest the right system size.
DIY vs Professional
In Western Australia, it is illegal to perform your own electrical work. While you can change a lightbulb or reset a switch, anything involving wiring or removing fittings must be done by a licensed electrician.
How we can help
If you haven't been able to resolve the issue with the steps above, it's time to call in the experts. Sparky Local carries the necessary diagnostic tools to identify the root cause quickly and safely.
Need a Professional?
Don't risk your safety. Our licensed electricians are available to assess and fix electrical issues properly.
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