Sizing a Battery to Match Your Inverter
When pairing a solar battery with a hybrid inverter, it’s essential to match the battery’s continuous power output to the inverter’s rated output. While battery capacity (kWh) determines how much energy you can store, it’s the continuous power (kW) that dictates how much energy can be delivered to your home or business at any moment.
If the battery’s continuous output is lower than the inverter’s capacity, the inverter won’t be able to operate at full power — limiting performance during peak usage or backup mode. On the flip side, if the battery is oversized, you may not utilise its full potential unless you upgrade the inverter.
For optimal performance and return on investment, the goal is simple:
🔧 Match or slightly exceed the inverter’s output rating with your battery’s continuous power.
At Marshall Solar and Energy, we help you get this balance right — ensuring your system is powerful, efficient, and future-ready.
Example: Sungrow SH8.0RT + SBR096 with a 6 kW Load
System setup:
- Inverter: Sungrow SH8.0RT (8 kW rated output)
- Battery: SBR096 (9.6 kWh usable capacity, 3.84 kW continuous output)
- Load: 6 kW (household demand during peak tariff period)
- Tariff: Peak time (expensive grid power)
What Happens in This Scenario?
- The SBR096 battery can only continuously supply 3.84 kW.
- Your home is demanding 6 kW of power.
- The inverter will pull 3.84 kW from the battery, and the remaining 2.16 kW will be imported from the grid at peak prices.
- Even though your inverter can handle 8 kW, the battery is limiting the usable output due to its continuous power cap.
Key Insight:
Your inverter is capable, but the battery is underpowered for peak usage — so grid import still occurs even with a charged battery.
Recommended Fix:
To cover the full 6 kW load during peak times, you’d need at least an SBR160 battery (6.4 kW cont. output) or higher — such as SBR192 for future load growth or backup capacity.
| Battery | Usable Capacity | Cont. Power | SH5.0RS (5 kW) | SH6.0RS (6 kW) | SH8.0RS (8 kW) | SH10RS (10 kW) |
|---|---|---|---|---|---|---|
| SBR096 | 9.6 kWh | 3.84 kW | ✅ Inverter max power not available due to battery limit | ✅ Inverter max power not available due to battery limit | ⚠️ Inverter max power not available due to limitations of battery cont. power | ⚠️ Inverter max power not available due to limitations of battery cont. power |
| SBR128 | 12.8 kWh | 5.12 kW | ✅ Inverter full output possible | ⚠️ Inverter max power not available due to limitations of battery cont. power | ⚠️ Inverter max power not available due to limitations of battery cont. power | ⚠️ Inverter max power not available due to limitations of battery cont. power |
| SBR160 | 16.0 kWh | 6.40 kW | ⚠️ Capped @5 kW | ✅ Inverter full output possible | ⚠️ Inverter max power not available due to limitations of battery cont. power | ⚠️ Inverter max power not available due to limitations of battery cont. power |
| SBR192 | 19.2 kWh | 7.68 kW | ❌ Capped @5 kW | ⚠️ Capped @6 kW | ✅ Inverter full output possible | ⚠️ Inverter max power not available due to limitations of battery cont. power |
| SBR224 | 22.4 kWh | 8.96 kW | ❌ Capped @5 kW | ❌ Capped @6 kW | ✅ Inverter full output possible | ⚠️ Inverter max power not available due to limitations of battery cont. power |
| SBR256 | 25.6 kWh | 10.24 kW | ❌ Capped @5 kW | ❌ Capped @6 kW | ❌ Capped @8 kW | ✅ Inverter full output possible |
