Buying Guide
How to Buy Home Batteries
Everything you need to know before buying a home battery. Size it right, choose wisely, and avoid common mistakes.
By Bec Ramirez
10 min read
The federal rebate takes about $3,610 off a 14 kWh battery installed before 1 January 2027, when it steps down.
Current battery rates end 1 January 2027 · 80 days remaining
What size battery do you need?
| Your Evening Usage | Recommended Size | Backup Duration | Typical Home |
|---|---|---|---|
| Low evening usage (5 to 8 kWh) | 5 to 6 kWh | 4 to 6 hours essentials | Small household, mostly daytime use |
| Average evening usage (10 to 15 kWh) | 10 kWh | 8 to 10 hours essentials | Average family, some evening appliances |
| High evening usage (15 to 20 kWh) | 13 to 15 kWh | 12+ hours essentials | Large family, AC, pool pump |
| Very high / whole home backup | 20+ kWh | 24+ hours whole home | Large home, EV, complete independence |
Your ideal battery size is roughly equal to your daily solar export. Check your inverter app or ask your retailer for your average daily export figure.
Buying checklist
Common mistakes to avoid
Buying too large a battery
Problem: Spending extra money on capacity you wont use daily. Payback takes longer.
Solution:Match battery size to your evening usage and solar export, not maximum capacity available.
Ignoring power output (kW)
Problem: A large battery with low power output cant run high-draw appliances like air conditioning.
Solution:Check both capacity (kWh) AND power output (kW). Match power to your peak demand.
Assuming all batteries do backup
Problem: Many batteries require additional hardware for blackout backup, adding $500 to $2,000.
Solution:If backup is important, confirm it is included and which circuits will be backed up.
Not checking inverter compatibility
Problem: Some batteries only work with specific inverters. May need expensive upgrades.
Solution:If adding to existing solar, confirm the battery works with your current inverter.
Battery installations are a bigger investment than panels alone, so installer stability matters even more. Over 270solar companies have collapsed in Australia since 2010, each leaving its customers without a workmanship warranty. Before committing, check our collapsed solar companies tracker and make sure your installer has been trading for at least 5 years.
Your battery rebate, checked before you sign
The federal rebate takes about $3,610 off a 14 kWh battery installed before 1 January 2027, when it steps down. One Why Solar Approved installer near you, and fifteen minutes with a solar expert before you sign.
Current battery rates end 1 January 2027 · 80 days remaining
Questions to ask installers
Helpful resources
The next step
If you're considering a home battery system, Bec and the team can match you with one Why Solar Approved installer near you for a free written quote, and fifteen minutes with a solar expert before you sign.
Written by
Aussie Mum & Energy Expert
Helps families switch to solar with practical, real-world advice. Bec focuses on the financial side: rebates, bill savings and financing options, so everyday Australians can see real value from going solar.
If you have any questions about the information in this guide, email hello@whysolar.com.au or call +61 2 5657 6527.