How Is a Battery Sized?
There's no one-size-fits-all answer. The right battery size depends on two things:
- What you want to back up
- How large your solar system is
What You Want to Back Up
Whole-home backup:
- Requires more capacity
- Powers everything (AC, dryer, all circuits)
- Higher cost, shorter backup duration
Critical circuits only:
- Requires less capacity
- Powers essentials (lights, refrigerator, router)
- Lower cost, longer backup duration
💡 Most Venture Home battery installations back up critical circuits, not the entire home.
Your Solar System Size
- Larger solar system → can recharge battery faster during outages
- Smaller solar system → may need larger battery to get through cloudy periods
The Conversation That Drives the Recommendation
When you contact us, it helps to think about:
- What would you want powered during an outage?
- How long do outages typically last in your area?
- Do you have medical equipment or other critical needs?
- What's your budget?
We'll design the system around your specific goals.
Common Battery Sizes
| Battery | Typical Backup (Essentials) | Best For |
|---|---|---|
| 10-13 kWh | 12-24 hours | Most homes, critical circuits |
| 20-27 kWh | 24-48 hours | Larger homes, longer outages |
| 40+ kWh | 2+ days | Whole-home backup, medical needs |
With solar charging: Duration extends significantly on sunny days
Related Articles
- [[battery-add-on|Adding a Battery to Your Existing Solar System]] — Full process and compatibility
- [[battery-duration-factors|How Long Will My Battery Last?]] — Understanding backup duration
- [[backup-reserve|What Is Backup Reserve and How Should I Set It?]] — Optimizing your backup
Ready to explore battery options? Contact Customer Success at 800-203-4158.