How Big Does My Battery Need to Be?

Backup batteries aren't one-size-fits-all. Whether you're a homeowner looking for peace of mind during a power outage, or a business protecting critical systems, sizing your battery backup correctly is essential.

At BC Solar, we don’t guess — we engineer. Here’s what you need to know:

For Homeowners in Columbus

Most residential systems are designed to cover “essential loads” — the appliances and systems you absolutely need running during an outage. This usually includes:

• Fridge and freezer

• Wi-Fi router

• Lights in key areas

• Sump pump or well pump

• Furnace fan or small AC

For that kind of backup, most homes need between 10 to 30 kWh of battery storage.

👉 Want to back up your whole home, including HVAC? You’ll need more capacity — we’ll help you calculate exactly how much.

For Businesses in Central Ohio

Sizing for commercial backup depends on:

• What equipment is mission-critical (e.g., servers, refrigeration, safety systems)

• How long you want to run it during an outage

• Peak load management goals (more on this below)

Systems can range from 30 kWh to several hundred, depending on the operation. That’s why every commercial project starts with a load analysis and often includes data logging to track real-time usage.

💡 Good to know: BC Solar designs systems that don’t just protect against outages — they can also help reduce demand charges by shaving peak load spikes.

How We Size Your Battery

We use real-world data to design your system. Our process includes:

1. Understanding your goals — emergency backup vs. long-duration off-grid use

2. Reviewing electric bills or usage data (especially your peak usage)

3. Mapping your critical loads

4. Designing a system that balances capacity, budget, and future scalability

And we’re battery agnostic — whether it’s Sol-Ark, EG4, or Tesla Powerwall, we build the system around your needs, not what we’re paid to sell.

Real-World Example

One Columbus homeowner added a third battery to their system after realizing they wanted longer runtime during grid outages. Their setup now provides seamless power to their entire first floor, including fridge, lights, and internet, for over 48 hours.

FAQ: Battery Backup in Columbus

How long will a 10 kWh battery last during an outage?
It depends on what you're powering. If you're running only essentials like a fridge, lights, and a router, it could last 12–24 hours.

Can I add batteries later?
Yes. We design modular systems, so you can start with one battery and add more over time.

Can batteries charge from the grid if solar isn't producing?
Absolutely. Our systems can pull from the grid when needed — especially helpful during winter or multi-day storms.

Do I need solar panels to install a battery?
Not necessarily. In fact, some businesses use batteries without solar to reduce demand charges or provide backup for specific systems.

At BC Solar, we’re not just selling hardware — we’re helping you take control of your power.

📍 Serving Columbus, Ohio and surrounding communities.

Let’s design your system the right way, with no guesswork.

Call (614) 442-9700 or visit https://bc.solar to schedule a free site assessment.