When designing a solar-plus-storage system, the most common question is: "How much battery do I actually need?" The answer depends on your energy consumption, solar production, and backup goals. Let is break it down with real numbers.
What 5kWh Can Power
A 5kWh system is ideal for essential backup during grid outages. With a 5kWh battery, you can run:
- Refrigerator (150W × 24h = 1.8kWh/day) — continuous
- LED lights (10 × 10W × 5h = 0.5kWh/day) — comfortable lighting
- WiFi router (10W × 24h = 0.24kWh/day)
- Laptop/phone charging (0.3kWh/day)
- Total: ~3kWh/day — well within 5kWh capacity with margin
Runtime without solar: 8–12 hours for essential loads.
What 10kWh Can Power
Doubling to 10kWh unlocks significantly more capability. You can add:
- Television (100W × 5h = 0.5kWh/day)
- Microwave (1000W × 0.5h = 0.5kWh/day)
- Washing machine (500W × 2h = 1kWh/day, used during solar hours)
- Small water pump (0.5kWh/day)
- Total: ~6kWh/day — comfortable family living
Runtime without solar: 16–24 hours for a typical family home.
BESTAR Product Mapping
| Use Case | Recommended | Capacity |
|---|---|---|
| Essential Backup | Wall-Mounted 5kWh | 5.12kWh |
| Family Home | All-in-One 5kW | 5.12kWh |
| Extended Backup | Stackable 10kWh | 10.24kWh |
| Whole Home | HV Cabinet 20kWh | 20.48kWh |
Solar Panel Sizing
For optimal self-consumption, pair your battery with enough solar. A good rule of thumb:
- 5kWh battery → 3–4kW of solar panels
- 10kWh battery → 5–6kW of solar panels
- 20kWh battery → 8–10kW of solar panels
Not Sure Which Size Fits Your Home?
Send us your monthly electricity bill and we will design a custom system.
Get a Custom Design