Gridly
Home Battery Sizing Calculator
Find the right home battery size for your household. Enter your daily energy use, solar system, and backup goals to get a recommended battery capacity.
Check your electricity bill - typically 15-35 kWh for Australian households
Enter 0 if no solar
Energy used after 5pm - this is what the battery primarily covers
Your Results
Recommended minimum (kWh)
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covers evening load + backup goal
Recommended optimal (kWh)
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with 25% headroom for degradation
Daily cycles needed
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charge/discharge per day
Evening load covered
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Backup capacity
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Solar surplus (est.)
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Suggested Products
| Battery | Capacity | Price | Best For |
|---|---|---|---|
| Sungrow SBR HV | 9.6-25.6 kWh (modular) | From ~$4,500 | Flexible sizing |
| BYD Battery-Box HVM | 8.3-22.1 kWh (modular) | From ~$5,200 | Any inverter brand |
| Tesla Powerwall 3 | 13.5 kWh | ~$14,500 installed | Backup + performance |
| Enphase IQ Battery | 10.5-42 kWh | From ~$9,500 | Enphase solar owners |
Sizing rule of thumb
Size your battery to cover your evening load (5pm-11pm) with 20% headroom. Adding backup capacity beyond your evening load significantly increases cost - only worth it if your area has frequent outages or you have medical equipment.