Should I back up my whole home or only essential loads?

Home Battery Backup Planning · By Good Faith Energy · Last reviewed October 2026

Key takeaways

Start with what you need during an outage, not with the battery size.
Large loads such as central air, electric heat, pool pumps and EV charging use battery energy fastest.
Solar can recharge a battery during a multi-day outage, but winter days and cloudy weather produce less.
A written backup plan should list exactly which circuits stay on.

Two ways to plan backup

Whole-home backup connects the battery to your entire electrical panel. Everything can run, but your usage decides how long the battery lasts. Essential-loads backup moves selected circuits, such as the refrigerator, lights, internet, outlets and medical equipment, onto protected power so the battery lasts longer.

Neither option is automatically better. The right choice depends on your budget, how long outages typically last where you live, and which appliances you cannot go without.

What changes how long a battery lasts

Heating and cooling: central air and electric heat are usually the largest loads in a Texas home.
Time of year: winter outages combine high heating demand with fewer hours of sunlight.
Solar production: panels can recharge the battery during the day if the system is designed for backup.
Household habits: running the dryer, oven or EV charger during an outage shortens runtime quickly.

Questions to ask before you buy

Which circuits will stay on during an outage, in writing?
How many hours of runtime should I expect in summer and in winter, with my usage?
Will my solar recharge the battery while the grid is down?
Does my electrical panel need an upgrade to support backup?

Frequently asked questions

Can one battery run my air conditioner?

Sometimes, depending on the unit size and the battery's power output. Ask your installer to check your specific equipment and how it affects runtime.

Will the battery switch on automatically during an outage?

Most backup systems switch automatically within moments. Confirm how your system behaves before installation.

Have a question about your home?

Talk with a Good Faith Energy specialist for a free consultation.