Combien de temps pouvez-vous exécuter une maison sur la batterie?

Combien de temps pouvez-vous exécuter une maison sur la batterie?
When the power goes out, the first question on everyone’s mind is, "How long will this last?" If you have a home battery backup, your next question is, "How long will my power last?" Understanding the runtime of your system is key to having true peace of mind and energy resilience.

The length of time you can run your house on battery backup depends entirely on two key factors: the energy capacity of your battery system (mesuré en kilowattheures, or kWh) and the amount of power your home is consuming (your electrical load). A typical modern wall-mounted battery backup of 10-15 kWh might run essential appliances for 12-24 heures, while a larger system could last for days, especially when recharged by solar panels.

An image of a home during a power outage, with the house lit up and powered by a sleek wall-mounted battery, with a clock graphic showing the hours passing.
Home Battery Backup Runtime During an Outage

À Gycx Solaire, we specialize in designing battery backup systems that meet our clients’ specific needs for runtime and energy independence. It’s not about a one-size-fits-all answer, but about creating a tailored solution. Let’s explore some of the most common questions about home battery backup.

Is a 10kW battery enough to run a house?

A 10kWh battery is a very popular size for home energy storage, but is it enough to run your entire house? It’s a great question, but first, we need to clarify terminology: the capacity of a battery is measured in kWh (kilowattheures), which is the amount of energy it stores.

UN 10kWh battery is often enough to run the essential circuits in a typical house for many hours or even overnight. This includes things like your lights, refrigerator, internet modem, fans, and some medical devices. Cependant, a single 10kWh battery is generally not enough to run an entire house, especially with large, power-hungry appliances like central air conditioning, for an extended period.

An infographic showing a 10kWh battery easily powering
What a 10kWh Battery Can Realistically Power

Plonger plus profondément: Sizing for Essentials vs. Whole Home

The answer to "is it enough?" depends on your goal.

  • Running Essentials: If your goal is to keep critical devices running during an outage, a 10kWh battery is a fantastic solution. If your essential loads add up to a continuous draw of 500 watts, a 10kWh battery could power them for nearly 20 heures (10,000 Wh / 500 W = 20 heures).
  • Running the Whole House: To run everything as normal, you need to consider your peak loads. A central air conditioner alone can draw 3,000-5,000 watts. If your total load is 4,000 watts (4 kW), that same 10kWh battery would only last 2.5 heures (10 kWh / 4 kw = 2.5 heures).

This is why modern wall-mounted battery backups are often modular. You can install a single 10kWh or 13.5kWh unit to cover essentials, or you can "stack" two or three units together to achieve the 20-30+ kWh capacity needed for true whole-home backup. À Gycx Solar, our design process starts with a load analysis to help you decide which level of backup is right for you.

Are battery backups better than generators?

For decades, the go-to solution for power outages was a fossil-fuel generator. But with the rise of modern battery backups, which option is better for today’s homeowner?

For most residential applications, un battery backup system is better than a generator. Batteries offer instantaneous and silent operation, produce no emissions, require virtually no maintenance, and can be seamlessly integrated with solar panels to recharge with clean energy. While generators may offer a lower initial cost for high power output, they are noisy, require ongoing fuel storage and maintenance, and create harmful exhaust fumes.

A comparison table showing a battery backup with icons for
Battery Backup vs. Generator Comparison

Plonger plus profondément: Comparaison de tête à tête

Let’s look at the key differences:

FonctionnalitéBattery Backup (BESS)Portable/Standby Generator
Response TimeInstantaneous. Power is seamless, you might not even notice the grid is down.Delayed. Requires manual start-up or an automatic transfer switch with a 10-30 second delay.
Noise LevelVirtually Silent. You’ll hear a quiet hum from the inverter at most.Very Loud. Can be disruptive to you and your neighbors.
FuelStores electricity from the grid or solar. No fuel required.Requires a constant supply of gasoline, propane, or diesel.
EntretienMinimal. No moving parts, no oil changes.Regular. Requires oil changes, fuel stabilizer, and periodic test runs.
EmissionsNone. Clean and safe to have installed in a garage or utility room.Harmful exhaust fumes (Carbon Monoxide). Must be placed far from windows and doors.
Running CostVery low or free when charged with solar.High and variable, depending on fuel prices.
IntegrationPerfect for solar self-consumption and maximizing your solar investment.A completely separate system.

While a generator might still have a place for some specific off-grid or industrial applications requiring very long runtimes without sun, for modern home resilience, a clean, quiet, and automatic battery backup system is the superior choice.

Do battery backups use a lot of electricity?

Does a battery backup system waste a significant amount of energy just by being connected and ready? It’s a fair question to ask whether the system itself is an energy drain.

Non, modern battery backup systems do not use a lot of electricity. They are designed to be highly efficient. The main energy "cost" is a small loss during the charging and discharging process, known as round-trip efficiency. A high-quality lithium battery system has a round-trip efficiency of 85-95% ou plus, meaning very little energy is wasted. They also have a minimal standby power draw to keep their electronics online and ready.

An illustration showing 10kWh of energy going into a battery system, with an arrow showing 9.5kWh of usable energy coming out, labeled
High Efficiency of Modern Battery Backups

Plonger plus profondément: Efficiency and Standby Loads

Let’s break down the energy a BESS uses:

  • Efficacité aller-retour (Rte): This is the main factor. If you put 10 kWh of solar energy into a battery with 95% Rte, you will get 9.5 kWh of usable electricity back out. Le 0.5 kWh is lost as heat during the conversion and chemical processes. This is a very low loss compared to other forms of energy storage. Older lead-acid systems, Par exemple, have a lower RTE of around 80-85%.
  • Standby/Idle Consumption: The system’s inverter and Battery Management System (GTC) need to be powered on 24/7 to monitor the system and be ready to provide power instantly. This standby load is typically very small, often between 20-100 watts. While it consumes some energy over a 24-hour period, it’s a tiny fraction of what the system can store and deliver.
  • Self-Discharge: As we’ve discussed in other articles, the battery itself will slowly lose a tiny amount of charge over time (1-3% per month for LFP lithium). Cependant, since the system is always connected, the float charge from the inverter easily compensates for this.

Compared to the massive amount of energy a wall-mounted battery backup can save you by storing solar power or the invaluable security it provides during an outage, the small amount of energy it uses to operate is negligible.

How many years does a battery backup last?

A battery backup system is a significant investment in your home’s infrastructure. How long can you expect this investment to last before it needs to be replaced?

A modern wall-mounted battery backup that uses LFP (Phosphate de fer au lithium) Chimie de batterie is a long-term asset with an expected operational lifespan of 10 à 20 années. These systems are typically backed by a 10-year manufacturer’s warranty that guarantees a certain level of performance, giving you confidence in their durability. This is a huge leap forward from older lead-acid battery systems, which often required replacement every 3-7 années.

A home with a wall-mounted battery and a calendar next to it flipping through 10+ years, indicating a long and reliable service life.
Long Lifespan of a Modern Home Battery Backup

Plonger plus profondément: The Makings of a Long-Lasting Battery System

The longevity of a modern battery backup is a result of several key technological advancements:

  • LFP Chemistry: Lithium Iron Phosphate is incredibly stable and robust. It can handle being charged and discharged daily for thousands of cycles without significant degradation. A battery rated for 6,000 cycles could theoretically last for over 16 years with one cycle per day.
  • Advanced Battery Management System (GTC1. ): The BMS is the battery’s guardian. It protects the cells from stressful conditions like overcharging, décharge excessive, et des températures extrêmes, all of which are crucial for extending its life.
  • Proper Thermal Management: The BESS enclosure, whether it’s a wall-mounted battery unit or a cabinet, is designed to dissipate heat and keep the cells operating in their ideal temperature range. This prevents premature aging.
  • The Warranty: A 10-year warranty is the industry standard for reputable home energy storage systems. It typically guarantees that the battery will retain a certain amount of its original capacity (Par exemple, 70%) by the end of the warranty term.

Gycx Solar Story: "When we talk to customers, we emphasize that they’re not just buying a battery, they’re investing in a decade or more of energy security. We exclusively use LFP-based systems from top manufacturers because their proven longevity ensures our clients receive the best possible long-term value."


Donc, are battery backups worth it? For homeowners seeking protection from power outages and a way to maximize their solar investment, the answer is a clear yes. A modern wall-mounted battery backup provides quiet, faire le ménage, and instantaneous power that is far superior to a generator. And with a lifespan of over a decade, it’s a durable and valuable addition to any home.

If you’re ready to explore how a battery backup can provide energy resilience for your family, our expert team at Gycx Solar is here to help you choose and size the perfect system. Contactez-nous dès aujourd'hui pour une consultation professionnelle!


  1. Comprendre le concept de BMS vous aidera à mieux comparer et comprendre les concepts de données liées à la batterie. Cela vous aidera à sélectionner le produit qui répond le mieux à vos besoins auprès de notre entreprise.

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