How can a home battery help in an emergency and when not?
WouterDecember 15, 2025
emergency power supplies with home batteries explained
Suppose: the power goes out. Not for a few minutes, but really long-term. The house goes dark, wifi goes down, devices stop working. Exactly such scenarios the national emergency plan describes: make sure you can save yourself in the first days when emergency services and grid operators can't be everywhere yet.
A home battery can make a huge difference then, depending on which home battery and configuration you choose. Here's what a home battery does for you during an emergency, what its limitations are, and how, with the right configuration, you can continue to use even large power consumers.
What a home battery means for you during an outage
When the lights go out at a neighbor's house, your house will continue to work. A home battery ensures that you:
- have lights
- can charge your phone and other small appliances
- your refrigerator and possibly your freezer continue to run
- wifi or other communication facilities remain online
- essential household appliances can continue to function properly
This happens automatically and without fuel or emissions. Especially during a failure, this gives security and continuity in the home.
But that only applies to systems that can actually provide backup. And that's where the big difference is.
Not every home battery is an emergency power system
There are roughly four types of solutions, and that difference is crucial.
1. Plug-in batteries with outlets
These are portable batteries that you can literally plug into. They are simple and flexible. During a power outage, you can plug devices directly into them, such as a lamp, phone charger or emergency communication equipment.
They are useful as an emergency supply, but are limited to individual devices. They do not power your home as a whole.
2. Home batteries connected to the meter box without a backup function
This is the standard configuration you see most often. The battery works in conjunction with the grid and solar panels, but drops out as soon as the grid goes down. This sounds contradictory, but is both a safety choice and an engineering feature. Without additional hardware, the inverter can't form an independent grid and the battery can't provide power in the event of an outage.
So, in a true emergency situation, you have no use for this. The battery is full, but your home is still de-energized.
3. Home batteries with partial backup
With these systems, a selection of groups are connected to the battery. Consider lighting, outlets for daily use, refrigerator and communication devices. Heavier consumers are deliberately included or excluded, depending on the system.
In the event of a power failure, the system automatically switches over. However, the power is limited by the inverter. Large appliances such as a washing machine or charging station are often placed outside the backup.
This is often a good balance between cost, technology and functionality. For this type of solution, systems from Anker SOLIX or SolarEdge Technologies are often chosen in practice.
4. Home batteries with full home backup
These are the most comprehensive systems. They can power the entire home during an outage. This requires a heavier inverter and an installation explicitly designed for it.
Brands such as Sigenergy Netherlands, Enphase Energy and HYXiPOWER are strong in this. This is the closest thing to off-grid, although even here the total capacity remains ultimately finite.
With this type of system, a larger battery capacity is often chosen. In the battery settings, you can define how much energy is always reserved for emergency power. In winter, this reserve is usually set higher than in summer because of the lower solar yield.
Those who want maximum security even in the event of prolonged outages choose an emergency power configuration with a smart energy port. This allows a generator to be connected to recharge the batteries if necessary.
And what about solar panels during an outage?
Many people think, "I have solar panels, so I always have power." Unfortunately, that doesn't work automatically.
In most installations, the inverter shuts down as soon as the grid goes down. Result: the sun is shining, but you can't use the power.
What does work is choosing the right configuration:
- an inverter capable of emergency power and powered by the battery during an outage
- solar panels connected directly to the battery in a backup configuration
Only then can you continue to generate during the day and recharge your battery. That makes the difference between a few hours and several days of self-sufficiency.
The use of large energy consumers during emergency power
Many communications about emergency power say that appliances such as heat pumps, electric water heaters, electric stoves and washing machines cannot be used on a battery. For small systems, this is true. However, the whole story is more nuanced.
For batteries of, say, 10 kWh or more, combined with a powerful inverter and a grid-forming home battery, it is possible to use heavier appliances as well, provided the system is technically designed to do so. For example:
- the refrigerator and freezer continue to function
- a heat pump for space heating or hot water
- washing clothes or using the dishwasher
- cooking on induction
In the summer, a system with enough solar panels and storage can be self-sustaining, as long as the energy consumption is adjusted accordingly. In that case, a self-sustaining, self-generating energy system is created.
Choices in energy use during emergency power
Emergency power is all about making choices. Every device you turn on consumes energy. That is why it is important to determine what is really needed at that moment.
That means:
- deploy energy-intensive devices only when functionally necessary
- take into account the remaining battery capacity and emergency power duration
- adjust inverter power and battery capacity to the intended use
Based on these principles, an emergency power system can be purposefully designed and realized. In doing so, it also helps to adjust your expectations during an outage. The house does not have to be fully heated to 22 degrees, and an electric car does not have to be fully charged immediately in such a situation.
Internet and communication during emergency power
During a power outage, the Internet is not naturally available, even if your modem and router are powered via a home battery. If the outage extends across the street, neighborhood, city or larger area, often the Internet provider's infrastructure is down as well. Consider district cabinets and exchanges that have no or limited emergency power themselves. In that case, the network remains unreachable, regardless of whether you still have power at home.
For those who want to maintain Internet access even during prolonged outages, alternatives such as mobile Internet or satellite Internet, for example through Starlink, are an option. These types of solutions function independently of the local network infrastructure, but do require additional equipment and power.
Which emergency power solution suits your situation?
This article has discussed four different home battery emergency power solutions. Which solution suits you best depends on your personal situation and expectations. How many solar panels do you have, how far do you want to be prepared for emergencies or a power grid that may become less reliable, what equipment do you want to be able to continue to use during an outage and what budget fits.
There is no standard solution that works for everyone. It is about finding the right balance between capacity, power, autonomy and comfort, tailored to your home and use.
If you want, SunCharged can think with you and design and realize a suitable emergency power system based on that.
