When you add a battery, you also decide what it powers during an outage. You can back up a short list of key circuits or most of the home. Both work well. The right choice depends on what you need during an outage, how long you want stored power to last, and how much storage you're installing.
Backing up the essentials
With an essentials setup, you move the circuits you care most about to a separate subpanel, often called a critical loads panel. When the grid goes down, the battery powers that subpanel and nothing else.
A typical essentials list includes the refrigerator, some lights, the internet router, a few outlets for phones and laptops, and, on rural properties, the well pump. Those loads draw relatively little power, so a battery can run them longer on the same charge.
The tradeoff is that everything outside that panel goes dark during an outage. Larger loads such as an electric range, a dryer, or central air conditioning usually stay off the backed-up circuits. For many households, that's an easy trade. The things that matter most keep working, and the stored power stretches further.
Backing up most of the home
With a whole-home setup, the battery is connected so it can power most or all of your circuits during an outage. You don't have to think about which outlets work and which don't. The house runs much as it normally would.
That convenience comes with two considerations. Running more of the home uses stored power faster, so you'll want to be thoughtful about large appliances during a long outage. Supporting bigger loads also takes more battery capacity and output, which may mean more than one battery. Some heavy loads, like a well pump or air conditioner, draw a surge of power when they start, and the battery has to be able to supply it.
How to decide
A few questions usually settle it.
- What do you need during an outage? If the answer is the refrigerator, lights, internet, and a few outlets, an essentials setup covers it well. If you work from home, have family members who need the house fully running, or simply want outages to go unnoticed, whole-home backup may be worth it.
- How long do you want your stored power to last? The fewer circuits you back up, the further your charge goes. Because your solar panels recharge the battery during the day, even an essentials setup can carry you through a multi-day outage if you use it carefully.
- How much storage are you installing? Essentials backup fits comfortably with a single battery in many homes. Whole-home backup with large loads often calls for more. Our post on how many solar batteries you need covers sizing.
- What does your electrical panel allow? Some setups move circuits to a new subpanel. Others back up the main panel directly. Which one fits depends on your existing panel and how your home is wired, which we review during the site visit.
What this looks like in practice
Two households can reach different answers for good reasons.
A retired couple in a single-story home might back up the refrigerator, the kitchen and bedroom lights, the internet, the garage door, and a couple of outlets. They don't need the dryer or the oven during an outage, and keeping the list short means one battery can carry them through a long one.
A family with two people working from home and an electric car in the garage might want nearly everything on. Losing the office, the kitchen, or the ability to charge the car would disrupt their week. For them, whole-home backup with more storage is worth it, with the car charger set to run only when the battery has charge to spare.
Neither is the right answer for everyone. The point is to match the setup to how your household lives, including who's home during the day and what they rely on.
The middle ground
You don't have to choose between a small list and everything. Many homeowners back up most of the house but leave off one or two large loads they can live without during an outage. Others start with essentials and add storage later as their needs grow. Smart panels can also help, letting you turn individual circuits on or off from an app during an outage so you decide in the moment where your stored power goes.
Pair the setup with the right settings
Whichever setup you choose, your backup reserve setting controls how much charge is held aside for an outage. With an essentials setup, a modest reserve often goes a long way. With whole-home backup, holding more in reserve during storm season makes sense. Our post on home battery settings explains how to adjust it, and our storm season post covers how to get ready for winter.
We'll help you decide
During the site visit, we review your electrical panel, usage history, and the loads that matter most to you, then recommend a setup and battery size to match. If essentials make the most sense, we'll say so. If whole-home backup is worth it for your household, we'll explain what it takes.
We've designed battery storage systems across Marin, Sonoma, and Napa since 1984. We're 100% employee-owned, licensed as a General Contractor (B) and Electrical Contractor (C-10), and one of the first companies in California to obtain the state's C-46 solar license.
Want help choosing what your battery should power? Contact SolarCraft or call Sonoma/Napa 707.778.0568 or Marin 415.382.7717.
