Calculator, battery size
Battery Size Calculator
Estimate a usable capacity range from your evening electricity usage and how many days of backup autonomy you want. Actual sizing is confirmed against your interval data.
Assumptions
Usable depth of discharge 90% · sizing buffer +15% for degradation and cold-weather performance. A range is shown because chemistry, inverter pairing and household load variability change the ideal capacity.
Recommended usable capacity
- Evening usage
- 12 kWh
- Autonomy target
- 1 day
- Recommended usable capacity
- 13.8 – 19.2 kWh
- Typical product bands
- 5–10 / 10–13.5 / 13.5–20 / 20 kWh+
Indicative only, subject to bill review and site assessment.
02Methodology
How we size a battery.
We take your evening usage, multiply by desired autonomy days, apply a depth-of-discharge factor and a safety buffer for degradation and cold weather. A proper design also checks your solar generation profile, inverter compatibility and panel layout.