How Long Will a Home Battery Backup Last During a Power Outage?

A common question we get at BC Solar from homeowners in Columbus is:

“How long will my battery backup keep the power on during an outage?”

The honest answer: it depends.

What Determines Battery Backup Runtime?

Several key factors influence how long your home battery system will last during an outage:

• Battery size (measured in kWh)

• How many devices or circuits you’re powering

• Whether you have solar panels to recharge the batteries

• Efficiency and smart management of energy usage

Let’s break it down simply:

• A typical 10 kWh battery can power essential loads—like your refrigerator, Wi-Fi, a few lights, and outlets—for about 10-15 hours, depending on usage.

• With multiple batteries and a smart inverter setup, some of our customers in Columbus have run their full homes for several days without grid power.

• If you have solar panels with battery storage, your system can recharge itself during the day, giving you power resilience that can last indefinitely.

We don’t just design for “sunny day” scenarios—we design for real-world conditions in Ohio, like cloudy days and cold winters.

Examples from Real BC Solar Customers

• One Columbus homeowner with a single battery and solar runs essentials for over 24 hours during outages.

• Another family with three batteries and full-home solar ran their house for three straight days last winter when the grid failed—heat, lights, everything.

We Design for Your Needs

At BC Solar, we don’t believe in cookie-cutter installs. Brian and the team custom design each system to match:

• Your backup priorities (just essentials or whole-home?)

• The reality of your local utility reliability

• Your budget and long-term energy goals

We'll give you real numbers, and help you weigh the trade-offs.

FAQs

How many batteries do I need for full backup?

Most homes need two to three batteries (around 20–30 kWh total) for full-day backup without solar. With solar recharging, you may need less depending on your consumption and panel production.

Will solar panels keep charging batteries during an outage?

Yes, if you have the right inverter (like a Sol-Ark or similar hybrid inverter). Grid-tied-only systems will not charge batteries when the grid is down.

Can I choose what gets backed up?

Absolutely. We help you prioritize circuits—so your fridge and lights stay on, but maybe not your dryer. We call this critical load design.

Want to know what backup looks like for your home?
We’ll give you honest advice and real-life examples from your neighbors in Columbus.