Battery Storage

What is a Home Battery?

There are a few different home battery options on the market that you can choose from. For starters, you’ll need to assess your homestead to see if it’s a good fit for a home battery or to see if your current system can be better utilized.

Last updated

June 30, 2024

Author: Matt from Currents

Learn about energy for your home or business.

A home battery is a storage system in which energy from the power grid or a nearby renewable energy source like wind and solar is stored in. It’s a piece of technology that allows you to store energy, from the grid or from your solar panels, in order to power your home and appliances.

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A home battery can be used as a backup energy source during times when the grid is down; for example, when a storm cuts the power, and you need to power the fridge to keep your food fresh or keep your A/C powered on. It can also be used to reduce your utility bills through time-of-use rates.

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Tesla powerwall — Tesla Powerwall powering a home

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Time of use, or TOU, is an opt-in utility program that allows you to pay a lower rate when using power during off-peak hours and a higher rate during on-peak hours. During peak hours, electricity will have a higher price because there is tons of demand for heating, cooling, EV charging and more.

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Time of use reflects the true cost of this electricity supply and demand by reducing prices during off-peak hours (typically overnight), allowing homeowners to take advantage of significantly lower prices leading to huge utility bill savings. Batteries empower you to do this.

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Homes usually have higher energy demands in the mornings and evenings, leaving the afternoon a good time for a home battery to source energy from the sun (if it’s hooked up to solar power). You can use a home battery backup without solar by keeping it on the grid behind-the-meter or by allowing it to store your rooftop solar power in the daytime, and discharging the power to your appliances at night.

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Here at Currents, we’ll get into what a home battery actually is, and you can decide if you need to purchase one or not to use in your home.

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What is a Home Battery?

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Electricity powers appliances and keeps the lights and A/C on. Without it, we’d not be able to do tasks like work from home at the computer comfortably or cook food using vegetables and meat refrigerated in the fridge. That’s why storing energy can be important - for the times when we lose access to the grid, the place where we normally receive our energy, and we need power.

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FranklinWH home battery — Franklin home battery system

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Most, if not all, home batteries on the current market are lithium-ion, which is a rechargeable battery that has charge/discharge cycles. A lithium-ion battery is capable of holding more energy than a regular battery of the same size, thus having a better performance including a better battery life and faster charging.

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While lithium-ion batteries are known to be sensitive to high heat temperatures, modern lithium-ion battery technology allows for the battery to not degrade in extreme heat as much as it otherwise would or could. There are other battery chemistries on the market, however lithium-ion has shown to be the most cost-effective at scale for now.

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As for how many batteries it takes to power a home, a home battery backup system can take anywhere from 1 to 4 to 10 batteries depending on your home, your energy requirements, and the batteries themselves. Home batteries are expected to last 10 to 12 years, or less, if the battery itself putters out before then (the warranty may or may not cover this).

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Do You Need a Home Battery?

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Home batteries are a reliable source of energy during a blackout, and thus it’s really not the most necessary purchase for a home-owner on the grid who doesn’t experience common losses of connection to the grid.

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However, we believe that every home of the future will have a home battery of some sort due to rising electricity prices across the country and an increase in renewables. Because of this, home batteries can make sense for homes without solar panels.

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Benefits include significant reduction in your utility bills, a more resilient neighborhood, and more.

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While most home batteries today are lithium ion, we believe the idea of a “home battery” will soon include major appliances like induction stoves, water heaters (a thermal battery), and more.

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rooftop solar panels — Home batteries pair well with rooftop solar

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For now, most home batteries make sense to store solar energy. Because net metering is being phased out across the country, home batteries make it a no brainer to store the power you produce on-site at your home. Purchasing solar for your home is a good start and you can consider purchasing a home battery later on, as popular batteries are AC-coupled and can be connected to solar already installed very easily.

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FAQs

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What else will I need for a home battery upgrade?

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Most homes will require an electrical service upgrade to attach a home battery system. An electrical service upgrade means swapping out your electrical panel for something that can handle a larger electrical load, namely a 200 amp panel rather than 100 amp panel. In order to know what you’ll need, we suggest reaching out to Currents. Our installation partners will require a few photos of your electrical panel to determine which upgrades work best.

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How much does a home battery cost?

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The average cost of a home battery is between $5,000 - $15,000. Your residential battery storage requirements may be around 10.1 kWh, which is the amount of battery storage the average home requires. The cost depends on the battery itself - the brand, the capacity, the type, installation, backup power, and the features included. This price only includes the battery itself, not other components needed or wanted, such as solar.

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Which home battery is best?

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For residential energy storage, the Tesla home battery, the Powerwall, is the best battery on the market today and costs around $8,000 plus installation costs. The Powerwall comes with options to install solar with your purchase at your residential home or to install the system without it. You can qualify for federal tax credits during your purchase. A close second to the Powerwall is the FranklinWH battery system, and Enphase makes the popular IQ battery.

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What is the best battery backup for a home?

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The best battery backup for a home is the Tesla Powerwall. The Powerwall has an energy capacity of 13.5 kWh and, depending on the model you choose, a continuous on-grid power of 5 kW for the Powerwall 2, 7.6 kW for the Powerwall+, or 11.5 kW for the Powerwall 3. All Tesla Powerwall models come with great backup power, a compact size, the ability to scale, and a 10-year warranty.

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How big of a battery would you need to power a house?

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The average home uses around 20 kWh of electricity per day, making a 10kWh battery large enough to be practical in the evening and overnight for a 3-bedroom home. The size of battery needed to power a house is determined by the size of your home, your appliances, and your energy usage patterns. A 5 to 6 kWh battery could work for an energy-efficient and energy-conscious home, but a completely off-grid system would require anywhere from 12 kWh to 30 kWh of battery capacity.

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