How Long Will a Home Battery Last in a Power Outage? A Las Vegas Runtime Guide

When the lights go out, the only number that matters is how many hours you have left. The honest answer to "how long will a home battery last?" is: it depends on what you ask it to run. The good news is that the math is simple, and once you see it, you can plan a Las Vegas home backup system that covers the hours you actually care about instead of guessing.

The one formula you need

Battery runtime comes down to this:

Hours of runtime ≈ usable battery capacity (kWh) ÷ the power you're drawing (kW)

If a battery holds 6 kWh of usable energy and your house is pulling 0.5 kW (500 watts), you get roughly 12 hours. Pull 2 kW and you get about 3 hours. Same battery, very different night.

That's why two neighbors with the same battery can report completely different results. One ran a fridge, Wi-Fi, and a few lights. The other tried to run the whole house.

What typical loads draw

These are rough, typical ranges. Your own appliances will vary, so check the labels or let us measure.

• Refrigerator: averages around 100–200 watts over time (it cycles on and off)
• Wi-Fi router and modem: about 20–40 watts
• LED lights: roughly 10 watts per bulb
• TV: about 60–150 watts
• Phone and laptop charging: small, usually under 100 watts combined
• Central air conditioning: often 3,000 watts or more while running
• Electric oven or dryer: several thousand watts

A "critical loads" setup (fridge, internet, lights, charging) often sits well under 500 watts on average. That's the kind of load a home battery can carry through a long evening and night.

Why air conditioning changes everything

In Southern Nevada summers, AC is the load everyone wants and the one that drains a battery fastest. A central unit pulling around 3 kW can empty a 6 kWh battery in about two hours. That doesn't mean AC is off the table. It means you size for it on purpose, with more capacity, a smaller zone, or a plan to run it in shorter cycles.

Solar recharge stretches the clock

A battery alone is a countdown. Add solar panels and the clock can reset every day. In Las Vegas, strong sun means panels can refill a meaningful share of a battery during daylight, so a multi-day outage becomes a cycle: use stored power at night, recharge by day.

This is where pairing an Anker SOLIX home battery with Watchdog solar panels pays off. The panels don't need to power the whole house. They just need to put back what your critical loads used overnight.

Three ways to get more hours

1. Trim the load. Decide ahead of time what really needs power. Fridge and internet usually make the cut. The electric dryer doesn't.
2. Add capacity. Many home battery systems can expand with extra battery modules, so you can start smaller and grow.
3. Add solar. Daytime recharge is the difference between "we made it through the night" and "we're fine all week."

A quick example

Say your critical loads average 400 watts and your usable capacity is 6 kWh. That's about 15 hours before solar. If panels put back several kWh during the day, you can keep the fridge cold and the router on through a multi-day outage without touching a generator.

Want AC too? Then we'd look at a larger battery bank, a dedicated circuit, or a smaller unit for one room. Every one of those is a sizing decision, not a guess.