To calculate how long your home solar battery will last during a power outage (or off-grid use), you'll need two key details:
- ① Your battery's usable capacity (in kWh)
- ② Your home's power consumption (in kW)
While no solar battery calculator fits all scenarios, you can estimate backup time manually or with online tools using this core formula:
Backup Time (hours) = Usable Battery Capacity (kWh) ÷ Connected Load (kW)
Example:
A typical 10kWh battery storage powering essential circuits (e.g., lights + refrigerator: 0.4kW~1kW) will last 10–24 hours during a blackout.
1. Understanding Solar Battery Amp Hours (Ah) & Watt-Hours
Your battery's capacity is crucial. It's measured in Amp Hours (solar battery Ah) or Watt-Hours (Wh).
- For example, a 48V solar power battery rated at 100Ah stores 4,800Wh (48V x 100Ah).
This tells you how much energy is available before needing a solar battery charge.
2. Calculate Your Solar Battery Bank Size
To calculate solar battery bank needs, list appliances you want to back up and their wattage. Add up their total daily Watt-Hour use. Decide how many days of backup you need (e.g., 1 day).
Multiply: Total Daily Use x Backup Days = Required solar battery storage capacity.
This solar battery sizing ensures your home solar battery meets your goals.
3. Using a Solar and Battery Calculator
A good solar and battery calculator simplifies the process! Please enter your location, typical energy use, desired backup appliances, and the size of your solar panel and battery system. The solar battery calculator then estimates:
- ✔ How long will my solar battery last during an outage.
- ✔ The ideal solar battery bank size for your needs.
- ✔ How to calculate charging time of battery by solar panel based on your solar array size.
⭐Here you can use the this useful Online Calculator (Input Your Data): Battery & Inverter Calculator Tool
4. Get the Right Backup Power
Using a solar battery charge calculator eliminates the need for guesswork. Know your solar battery amp hour capacity and consumption to confidently size your home solar battery system for dependable power when you need it most.